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Emergency IVF versus ovarian tissue cryopreservation: decision making in fertility preservation for female cancer patients

      Hundreds of thousands of women in their reproductive years are diagnosed with cancer each year. As the number of female patients who survive cancer increases, the demand for effective and individualized fertility preservation options grows. Currently there are limited clinical options for fertility preservation, and the paucity of publications describing clinical experience and outcomes data has limited accessibility to these options. Decision making for patients diagnosed with cancer requires up-to-date knowledge of the efficacy and safety of available techniques. This article describes a step-by-step approach to evaluation of the cancer patient and presents an accumulation of clinical experience with challenges unique to patients with breast cancer and leukemia. Current data on reproductive outcomes of fertility preservation techniques are examined, demonstrating increasing evidence that these techniques are becoming effective enough to offer routinely to patients facing gonadotoxic cancer therapies, including those still considered to be “experimental.”

      Key Words

      Discuss: You can discuss this article with its authors and with other ASRM members at http://fertstertforum.com/chungk-ovarian-tissue-cryopreservation-oncofertility/
      Hundreds of thousands of women in their reproductive years are diagnosed with cancer each year. By age 39 years, 1 in 51 women will have been diagnosed with an invasive cancer (

      Altekruse SF, Kosary CL, Krapcho M, Neyman N, Aminou R, Waldron W, et al. SEER cancer statistics review, 1975–2007. Bethesda, MD: National Cancer Institute. Available at: http://seer.cancer.gov/csr/1975_2007/. Last accessed March 8, 2013.

      ), and as the societal trend to delay child-bearing continues, many of these women will have not yet started or completed their families (

      National Center for Health Statistics. Birth rate for women age 15–44. Available at http://www.cdc.gov/nchs/pressroom/04facts/birthrates.htm. Accessed October, 29, 2008.

      ). Steady advances in cancer treatment have greatly improved survival rates, but population-based studies have demonstrated a consistent 30%–50% reduction in the probability of having a live birth in cancer survivors compared with control subjects (
      • Green D.M.
      • Whitton J.A.
      • Stovall M.
      • Mertens A.C.
      • Donaldson S.S.
      • Ruymann F.B.
      Pregnancy outcome of female survivors of childhood cancer: a report from the Childhood Cancer Survivor Study.
      ,
      • Magelssen H.
      • Melve K.K.
      • Skjaerven R.
      • Fosså S.D.
      Parenthood probability and pregnancy outcome in patients with a cancer diagnosis during adolescence and young adulthood.
      ,
      • Cvancarova M.
      • Samuelson S.O.
      • Magelssen H.
      • Fosså S.D.
      Reproduction rates after cancer treatment: experience from the Norwegian Radium Hospital.
      ), mainly owing to treatment strategies including chemotherapy and radiation. The potential for infertility is a considerable source of distress for patients with cancer, and there is a strong desire among survivors to have their own biologic offspring after completing cancer treatment (
      • Schrover L.R.
      • Rybicki L.A.
      • Martin B.A.
      • Bringelsen K.A.
      Having children after cancer: a pilot survey of survivors’s attitudes and experiences.
      ,
      • Reinmuth S.
      • Liebeskind A.K.
      • Wickmann L.
      • Bockelbrink A.
      • Keil T.
      • Henze G.
      • et al.
      Having children after surviving cancer in childhood or adolescence: results of a Berlin survey.
      ,
      • Hammond C.
      • Abrams J.R.
      • Syrjala K.L.
      Fertility and risk factors for elevated fertility concern in 10-year hematopoietic cell transplant survivors and case-matched controls.
      ).
      Recent evidence supports an increased frequency of referrals from oncologists to reproductive endocrinologists, and the demand for effective and individualized fertility preservation (FP) options grows (
      • Forman E.J.
      • Anders C.K.
      • Behera M.A.
      A nationwide survey of oncologists regarding treatment-related infertility and fertility preservation in female cancer patients.
      ,
      • Lee S.
      • Heytens E.
      • Moy F.
      • Ozkavukcu S.
      • Oktay K.
      Determinants of access to fertility preservation in women with breast cancer.
      ,
      • Quinn G.P.
      • Vadaparampil S.T.
      • Lee J.H.
      • Jacobsen P.B.
      • Bepler G.
      • Lancaster J.
      • et al.
      Physician referral for fertility preservation in oncology patients: a national study of practice behaviors.
      ). There are relatively few clinical options for fertility preservation, and, because of limited data on clinical outcomes, they have been considered experimental. The present article examines current data on clinical outcomes of FP techniques, including those labeled experimental, and provides increasing evidence that emergency IVF, oocyte cryopreservation, and ovarian tissue cryopreservation are effective enough to consider offering routinely to patients facing gonadotoxic cancer therapies. With this knowledge, clinical use of these techniques will be facilitated and the designation of the “experimental” label will be challenged.

      Approach to cancer patients referred to fertility preservation clinic

      Counseling of cancer patients considering FP procedures involves estimating the risk of sterilization and infertility from the upcoming cancer therapy. Decision-making and clinical application of FP strategies to specific cancer situations requires up-to-date knowledge of the efficacy and safety of all available techniques. This is of critical importance in determining whether the risks of undergoing an invasive FP procedure are warranted.

       Cancer Treatment and Ovarian Damage

      With increasing female life, progressive loss of primordial follicles occurs, resulting in the age-related decline in female fertility (
      • Faddy M.J.
      • Gosden R.G.
      A model conforming the decline in follicle numbers to the age of menopause in women.
      ,
      • Wallace W.H.
      • Kelsey T.W.
      Human ovarian reserve from conception to the menopause.
      ). At any age, ovarian follicles are vulnerable to agents that cause DNA damage, including ionizing radiation and chemotherapy. These anticancer treatments cause a reduction in the ovarian follicle reserve in a dose-dependent manner, and can ultimately induce amenorrhea and premature ovarian failure (
      • Meirow D.
      Reproduction post-chemotherapy in young cancer patients.
      ). Alternatively, partial ovarian injury can occur, in which the reduction in primordial follicle stockpiles is manifested by infertility and a shortened reproductive lifespan despite resumption of menses after cancer treatment (
      • Meirow D.
      Reproduction post-chemotherapy in young cancer patients.
      ). In these cases, postcancer treatment markers of ovarian reserve (antral follicle count, FSH, antimüllerian hormone [AMH], inhibin B) can resemble levels seen in perimenopausal women (
      • Bath L.E.
      • Wallace W.H.
      • Shaw M.P.
      • Fitzpatrick C.
      • Anderson R.A.
      Depletion of ovarian reserve in young women after treatment for cancer in childhood: detection by anti-müllerian hormone, inhibin B and ovarian ultrasound.
      ).

       Radiation-induced reproductive damage

      Cancer patients scheduled for abdominal, pelvic, and total body irradiation are at risk for infertility, shortened reproductive life span, and premature ovarian failure due to loss of primordial follicles. The degree of ovarian damage is determined by the total irradiation dose, location, fractionation schedule, and age at the time of treatment, with older women being at greater risk for ovarian failure. Radiosensitivity of the human ovary resulting in 50% loss of primordial follicles (LD50) is estimated to be 2 Gy (
      • Wallace W.H.
      • Thomson A.B.
      • Kelsey T.W.
      The radiosensitivity of the human oocyte.
      ). Age-related effective sterilizing dose (ESD) is 20.3 Gy at birth, 16.5 Gy at 20 years of age, and 14.3 Gy at 30 years of age (
      • Wallace W.H.
      • Thomson A.B.
      • Saran F.
      • Kelsey T.W.
      Predicting age of ovarian failure after radiation to a field that includes the ovaries.
      ,
      • Meirow D.
      • Biederman H.
      • Anderson R.A.
      • Wallace W.
      Toxicity of chemotherapy and radiation on female reproduction.
      ). Delayed onset of premature ovarian failure due to partial depletion of the ovarian reserve is common. When combined with chemotherapy, mainly alkylating agents, the risk of ovarian failure is further increased.
      Consultation prior to abdominal and pelvic irradiation should also consider damage to the uterus, because the patient should be aware of the possible future need for a gestational carrier. Uterine function can be affected by radiation doses of 14–30 Gy. After radiation exposure in childhood, reductions in uterine volume and endometrial thickness can be expected, leading to an increased risk of miscarriage, second-trimester pregnancy loss, preterm delivery, and low birth weight (
      • Critchley H.O.D.
      • Wallace W.H.B.
      • Shalet S.M.
      • Mamtora H.
      • Higginson J.
      • Anderson D.C.
      Abdominal irradiation in childhood; the potential for pregnancy.
      ,
      • Larsen E.C.
      • Schmiegelow K.
      • Rechnitzer C.
      • Loft A.
      • Muller J.
      • Andersen A.N.
      Radiotherapy at a young age reduces uterine volume of childhood cancer survivors.
      ). Uterine damage is usually irreversible, but some studies reported improvement in endometrial thickness in response to hormone replacement therapy (
      • Bath L.E.
      • Critchley H.O.D.
      • Chambers S.E.
      • Chambers S.E.
      • Anderson R.A.
      • Kelnar C.J.
      • Wallace W.H.
      Ovarian and uterine characteristics after total body irradiation in childhood and adolescence: response to sex steroid replacement.
      ).

       Chemotherapy-induced ovarian damage

      The risk of ovarian damage is strongly affected by age at the time of treatment, with older patients being more likely to experience ovarian failure (
      • Meirow D.
      Reproduction post-chemotherapy in young cancer patients.
      ,
      • Petrek J.A.
      • Naughton M.J.
      • Case L.D.
      • Paskett E.D.
      • Naftalis E.Z.
      • Singletary S.E.
      • et al.
      Incidence, time course, and determinants of menstrual bleeding after breast cancer treatment: a prospective study.
      ,
      • Goodwin P.J.
      • Ennis M.
      • Pritchard K.I.
      • Trudeau M.
      • Hood N.
      Risk of menopause during the first year after breast cancer diagnosis.
      ). The risk of ovarian failure is determined also by the type and regimen of chemotherapy, and these are highly relevant during consultation and decision about an FP procedure (
      • Meirow D.
      Reproduction post-chemotherapy in young cancer patients.
      ). For patients with breast cancer or Hodgkin lymphoma, common combination regimens and the reported rates of ovarian failure are presented in Table 1 (
      • Goodwin P.J.
      • Ennis M.
      • Pritchard K.I.
      • Trudeau M.
      • Hood N.
      Risk of menopause during the first year after breast cancer diagnosis.
      ,
      • Partridge A.H.
      • Burstein H.J.
      • Winer E.P.
      Side effects of chemotherapy and combined chemohormonal therapy in women with early-stage breast cancer.
      ,
      • Burstein H.J.
      • Winer E.P.
      Primary care for survivors of breast cancer.
      ,
      • Najafi S.
      • Djavid G.E.
      • Mehrdad N.
      • Rajaii E.
      • Alavi N.
      • Olfatbakhsh A.
      • et al.
      Taxane-based regimens as a risk factor for chemotherapy-induced amenorrhea.
      ,
      • Whitehead E.
      • Shalet S.M.
      • Blackledge G.
      • Todd I.
      • Crowther D.
      • Beardwell C.G.
      The effect of combination chemotherapy on ovarian function in women treated for Hodgkin’s disease.
      ,
      • Mackie E.J.
      • Radford M.
      • Shalet S.M.
      Gonadal function following chemotherapy for childhood Hodgkin’s disease.
      ,
      • Kreuser E.
      • Felsenberg D.
      • Behles C.
      • Seibt-Jung H.
      • Mielcarek M.
      • Diehl V.
      • et al.
      Long-term gonadal dysfunction and its impact on bone mineralization in patients following COPP/ABVD chemotherapy for Hodgkin’s disease.
      ,
      • Brusamolino E.
      • Lunghi F.
      • Orlandi E.
      • Astori C.
      • Passamonti F.
      • Baraté C.
      • et al.
      Treatment of early-stage Hodgkin’s disease with four cycles of ABVD followed by adjuvant radio-therapy: analysis of efficacy and long-term toxicity.
      ,
      • Hodgson D.C.
      • Pintilie M.
      • Gitterman L.
      • Dewitt B.
      • Buckley C.A.
      • Ahmed S.
      • et al.
      Fertility among female Hodgkin lymphoma survivors attempting pregnancy following ABVD chemotherapy.
      ,
      • Behringer K.
      • Breuer K.
      • Reineke T.
      • May M.
      • Nogova L.
      • Klimm B.
      • Schmitz T.
      • et al.
      German Hodgkin’s Lymphoma Study Group
      Secondary amenorrhea after Hodgkin’s lymphoma is influenced by age at treatment, stage of disease, chemotherapy regimen, and the use of oral contraceptives during therapy: a report from the German Hodgkin’s Lymphoma Study Group.
      ). In bone marrow transplantation candidates, preparative regimens of total body irradiation and/or multiple-agent chemotherapy cause consistently high rates of amenorrhea and ovarian failure, ranging from 72% to 100%. In contrast, medications used for the first line treatment for acute myeloid leukemia (AML) are not toxic to the ovaries, and clinical studies on AML survivors indicate that the chemotherapy protocols used are not associated with increased rate of acute ovarian failure or diminished ovarian reserve (
      • Meirow D.
      Reproduction post-chemotherapy in young cancer patients.
      ,
      • Meirow D.
      • Biederman H.
      • Anderson R.A.
      • Wallace W.
      Toxicity of chemotherapy and radiation on female reproduction.
      ,
      • Chemaitilly W.
      • Mertens A.C.
      • Mitby P.
      • Whitton J.
      • Stovall M.
      • Yasui Y.
      • et al.
      Acute ovarian failure in the childhood cancer survivor study.
      ). Not infrequently, cancer patients desire to perform FP procedures even when there is no plan for gonadotoxic treatment or after completion of cancer treatment. Decisions regarding FP options should take into consideration factors that influence the likelihood of diminished ovarian reserve after cancer treatment, including the common recommendation made by oncologists to wait 2–5 years after cancer treatment before attempting to conceive, and, in carriers of the BRCA mutation, the recommendation of bilateral oophorectomy by age 40 years.
      Table 1Reported ovarian failure rates by age and combination chemotherapy regimen in breast cancer and Hodgkin lymphoma patients (References
      • Goodwin P.J.
      • Ennis M.
      • Pritchard K.I.
      • Trudeau M.
      • Hood N.
      Risk of menopause during the first year after breast cancer diagnosis.
      ,
      • Partridge A.H.
      • Burstein H.J.
      • Winer E.P.
      Side effects of chemotherapy and combined chemohormonal therapy in women with early-stage breast cancer.
      ,
      • Burstein H.J.
      • Winer E.P.
      Primary care for survivors of breast cancer.
      ,
      • Najafi S.
      • Djavid G.E.
      • Mehrdad N.
      • Rajaii E.
      • Alavi N.
      • Olfatbakhsh A.
      • et al.
      Taxane-based regimens as a risk factor for chemotherapy-induced amenorrhea.
      ,
      • Whitehead E.
      • Shalet S.M.
      • Blackledge G.
      • Todd I.
      • Crowther D.
      • Beardwell C.G.
      The effect of combination chemotherapy on ovarian function in women treated for Hodgkin’s disease.
      ,
      • Mackie E.J.
      • Radford M.
      • Shalet S.M.
      Gonadal function following chemotherapy for childhood Hodgkin’s disease.
      ,
      • Kreuser E.
      • Felsenberg D.
      • Behles C.
      • Seibt-Jung H.
      • Mielcarek M.
      • Diehl V.
      • et al.
      Long-term gonadal dysfunction and its impact on bone mineralization in patients following COPP/ABVD chemotherapy for Hodgkin’s disease.
      ,
      • Brusamolino E.
      • Lunghi F.
      • Orlandi E.
      • Astori C.
      • Passamonti F.
      • Baraté C.
      • et al.
      Treatment of early-stage Hodgkin’s disease with four cycles of ABVD followed by adjuvant radio-therapy: analysis of efficacy and long-term toxicity.
      ,
      • Hodgson D.C.
      • Pintilie M.
      • Gitterman L.
      • Dewitt B.
      • Buckley C.A.
      • Ahmed S.
      • et al.
      Fertility among female Hodgkin lymphoma survivors attempting pregnancy following ABVD chemotherapy.
      ,
      • Behringer K.
      • Breuer K.
      • Reineke T.
      • May M.
      • Nogova L.
      • Klimm B.
      • Schmitz T.
      • et al.
      German Hodgkin’s Lymphoma Study Group
      Secondary amenorrhea after Hodgkin’s lymphoma is influenced by age at treatment, stage of disease, chemotherapy regimen, and the use of oral contraceptives during therapy: a report from the German Hodgkin’s Lymphoma Study Group.
      ).
      Chemotherapy regimenAge, yReported ovarian failure rate
      Breast cancer
       AC<300%
      30–3913%
      ≥4057%–63%
       FAC<300%
      30–3910%–25%
       CMF<3019%
      30–3951%–77%
      ≥4083%–98%
       + Taxanes79% (OR 4.05)
      Hodgkin lymphoma
       MVPP61%
       ChlVPP53%
       COPP/ABVD78%
       BEA/COPPOR 3.55
       ABVDUnlikely to cause ovarian failure
       BMT72%–100%
      Note: Definitions for ovarian failure vary by study. ABVD = doxorubicin, bleomycin, vinblastine, dacarbazine; BEA = bleomycin, etoposide, doxorubicin; BMT = bone marrow transplantation; AC = doxorubicin, cyclophosphamide; ChlVPP = chlorambucil, vincristine, procarbazine, prednisone; CMF = cyclophosphamide, methotrexate, fluorouracil; COPP = cyclophosphamide, vincristine, procarbazine, prednisone; FAC = fluorouracil, doxorubicin, cyclophophasmide; MVPP = mechlorethamine, vincristine, procarbazine, prednisone; OR = odds ratio.

       Evaluation of Patients Considering Fertility Preservation Procedures

      After the risk of sterilization from the upcoming cancer therapy has been elucidated, current health status, ovarian reserve, and time available before cancer treatment must be assessed. Pretreatment measures of antral follicle count and serum FSH and AMH have been reported to predict long-term ovarian function after chemotherapy in women (
      • Brougham M.F.
      • Crofton P.M.
      • Johnson E.J.
      • Evans N.
      • Anderson R.A.
      • Wallace W.H.
      Anti-mullerian hormone is a marker of gonadotoxicity in pre- and postpubertal girls treated for cancer: a prospective study.
      ) and in prepubertal girls (
      • Anderson R.A.
      • Cameron D.A.
      Pretreatment serum antimüllerian hormone predicts long-term ovarian function and bone mass after chemotherapy for early breast cancer.
      ) and should be considered during consultation. However, in many cases these parameters are not available in time. Those patients with good health, good ovarian reserve, ample time for FP, and high risk of sterilization are most likely to benefit from FP procedures. Decisions in other candidates must be individualized though the degree of fertility impairment after cancer therapy can be difficult to predict.
      Different types of cancer are associated with distinct challenges and concerns, which in turn influence the optimal approach to FP. These include hormone-sensitive tumors because of concerns about the safety of traditional ovarian stimulation protocols, which induce supraphysiologic serum E2 levels. In patients with leukemia and lymphoma, anemia and thrombocytopenia may necessitate transfusion before egg retrieval, and there is the risk of malignant contamination of the ovaries, precluding future transplantation of thawed ovarian tissue. Lymphoma patients may present with large thoracic masses causing airway obstruction, inferior or superior vena cava compression or pericardial tamponade. Cervical cancer patients may have bulky tumors impeding transvaginal access to the ovaries, or may have transposed ovaries requiring transabdominal egg retrieval.
      After initial evaluation of the patient and careful consideration of the risks and benefits of FP procedures, currently available methods to preserve fertility should be discussed and individually tailored to the patient.

       Ovarian Stimulation and In Vitro Fertilization for Embryo and Oocyte Banking

      For decades, embryo banking was the only method of FP that was not considered to be investigational by the American Society for Reproductive Medicine (ASRM) (
      Practice Committee of American Society for Reproductive Medicine; Practice Committee of Society for Assisted Reproductive Technology. Mature oocyte cryopreservation: a guideline.
      ). All centers offering assisted reproductive technologies (ART) have relatively vast experience with IVF and embryo cryopreservation, and pregnancy rates from cryopreserved embryos are generally well known within each program. Ideal candidates have a male partner or are willing to use donor sperm, and are able to safely delay the start of cancer therapy to allow for ovarian stimulation. For cancer patients without a male partner, oocyte cryopreservation is a real option and is no longer considered to be experimental (
      Practice Committee of American Society for Reproductive Medicine; Practice Committee of Society for Assisted Reproductive Technology. Mature oocyte cryopreservation: a guideline.
      ).
      Embryo and oocyte banking procedures must be completed before initiation of cancer therapies. Previous chemotherapy is likely to decrease the response to ovarian stimulation, and if attempted within 2–3 months of exposure, the ovaries do not respond or no oocytes are retrieved (
      • Meirow D.
      • Schiff E.
      Appraisal of chemotherapy effects on reproductive outcome according to animal studies and clinical data.
      ). Moreover, there are concerns that growing follicles exposed to chemotherapy may yield morphologically and genetically abnormal oocytes (
      • Meirow D.
      • Schiff E.
      Appraisal of chemotherapy effects on reproductive outcome according to animal studies and clinical data.
      ,
      • Kujjo L.L.
      • Chang E.A.
      • Pereira R.J.
      • Dhar S.
      • Marrero-Rosado B.
      • Sengupta S.
      • et al.
      Chemotherapy-induced late transgenerational effects in mice.
      ,
      • Bar-Joseph H.
      • Ben-Aharon I.
      • Rizel S.
      • Stemmer S.M.
      • Tzabari M.
      • Shalgi R.
      Doxorubicin-induced apoptosis in germinal vesicle (GV) oocytes.
      ). Administration of chemotherapy during follicle maturation has been shown to have deleterious effects on reproductive outcome, including high abortion and malformation rates as indicated by animal studies (
      • Kujjo L.L.
      • Chang E.A.
      • Pereira R.J.
      • Dhar S.
      • Marrero-Rosado B.
      • Sengupta S.
      • et al.
      Chemotherapy-induced late transgenerational effects in mice.
      ). Such adverse effects are not observed in primordial follicles that survive long term after chemotherapy exposure, because there is no increased risk of birth defects in women who conceive years after chemotherapy (
      • Winther J.F.
      • Boice Jr., J.D.
      • Mulvihill J.J.
      • Stovall M.
      • Frederiksen K.
      • Tawn E.J.
      • et al.
      Chromosomal abnormalities among offspring of childhood-cancer survivors in Denmark: a population-based study.
      ). Thus, cancer patients are advised not to perform IVF cycles and to delay attempts to conceive until ≥6 months (time needed for human oocyte maturation) from completion of chemotherapy (
      • Meirow D.
      • Schiff E.
      Appraisal of chemotherapy effects on reproductive outcome according to animal studies and clinical data.
      ).

       Selection of Ovarian Stimulation Protocols

       Timing

      Whether cryopreserving oocytes or embryos, the approach to selecting the stimulation protocol in the cancer population differs from that in the general infertility population, in part because of the limited amount of time available for FP before initiation of cancer treatments. In a study of breast cancer patients (19 patients) who underwent IVF for FP, the time from referral to oocyte retrieval did not result in a significant delay in the start of chemotherapy (median 32 days, range 13–66 days) suggesting that the timing of breast cancer treatments may allow for ovarian stimulation (
      • Baynosa J.
      • Westphal L.M.
      • Madrigrano A.
      • Wapnir I.
      Timing of breast cancer treatments with oocyte retrieval and embryo cryopreservation.
      ). However, in patients with acute leukemia, chemotherapy can not be delayed and there is no time for an IVF cycle, but ovarian tissue cryopreservation can be performed after chemotherapy (see subsequent section). GnRH antagonist protocols are generally preferred over long protocols owing to shorter duration of stimulation, lower exogenous gonadotropin requirements, and lower incidence of ovarian hyperstimulation syndrome (OHSS) (
      • Al-Inany H.G.
      • Youssef M.A.
      • Aboulghar M.
      • Broekmans F.
      • Sterrenburg M.
      • Smit J.
      • et al.
      Gonadotrophin-releasing hormone antagonists for assisted reproductive technology.
      ). The need to minimize the risk of OHSS is particularly important in cancer patients, because it could result in a delay of cancer treatment. Exogenous gonadotropins are conventionally initiated in the early follicular phase, or after pretreatment with oral contraceptive pills (OCP). However, significant increased duration of stimulation and gonadotropin requirement with OCP pretreatment has been reported (
      • Griesinger G.
      • Venetis C.A.
      • Marx T.
      • Diedrich K.
      • Tarlatzis B.C.
      • Kolibianakis E.M.
      Oral contraceptive pill pretreatment in ovarian stimulation with GnRH antagonists for IVF: a systematic review and meta-analysis.
      ).
      To avoid delay of chemotherapy initiation, ovarian stimulation has been initiated (40 cancer patients) in the luteal phase of the cycle or “at random,” and the number of mature oocytes were successfully retrieved was not statistically differently from follicular phase cycles (
      • von Wolff M.
      • Thaler C.J.
      • Frambach T.
      • Zeeb C.
      • Lawrenz B.
      • Popovici R.M.
      • et al.
      Ovarian stimulation to cryopreserve fertilized oocytes in cancer patients can be started in the luteal phase.
      ). The luteal-phase protocol uses GnRH antagonist to induce immediate luteolysis with daily injections of recombinant FSH until follicular maturity. Evidence supporting the feasibility of initiating ovarian stimulation at unconventional phases of the menstrual cycle (days 4, 5, 11, 14, and 17) has since been published, and in all cases, multiple mature oocytes were retrieved, ranging in number from six to thirty (
      • Nayak S.R.
      • Wakim A.N.
      Random-start gonadotropin-releasing hormone (GnRH) antagonist–treated cycles with GnRH agonist trigger for fertility preservation.
      ). Also when in vitro maturation (IVM) was used, the total number of mature oocytes at 48 hours was similar between luteal- and follicular-phase IVM (
      • Maman E.
      • Meirow D.
      • Brengauz M.
      • Raanani H.
      • Dor J.
      • Hourvitz A.
      Luteal phase oocyte retrieval and in vitro maturation is an optional procedure for urgent fertility preservation.
      ).

       Selecting gonadotropin dose and predicting response to stimulation

      Standard predictors of ovarian response, including day 3 FSH, E2, and AMH levels, are often not available until the start of stimulation. Patient age and antral follicle count can be helpful in estimating the gonadotropin dose, and it is common to decide on the dose on the day that stimulation is to be initiated. The aim is to select a stimulation protocol and dose that will yield an optimal number of oocytes but minimize the risk of OHSS. Because the presence of malignancy is known to adversely affect fertility in male cancer patients, even before exposure to gonadotoxic treatments, there is speculation that female cancer patients may also demonstrate reduced fertility and reduced response to gonadotropins before radiation or chemotherapy. A recent study of 223 cancer patients undergoing ovarian stimulation before chemotherapy reported significantly fewer oocytes and higher risk of poor response (four or fewer oocytes) in the cancer patients compared with a control group of patients undergoing IVF for male-factor infertility (
      • Domingo J.
      • Guillén V.
      • Ayllón Y.
      • Martínez M.
      • Muñoz E.
      • Pellicer A.
      • et al.
      Ovarian response to controlled ovarian hyperstimulation in cancer patients is diminished even before oncological treatment.
      ). Evaluation of AMH levels in 84 female patients with breast cancer and 64 patients with lymphoma before chemotherapy administration, compared with healthy control subjects, found significantly lower ovarian reserve in the lymphoma group. That study also showed significantly fewer oocytes in the lymphoma group compared with those with breast cancer, although the patients with lymphoma were significantly younger (
      • Lawrenz B.
      • Fehm T.
      • von Wolff M.
      • Soekler M.
      • Huebner S.
      • Henes J.
      • et al.
      Reduced pretreatment ovarian reserve in premenopausal female patients with Hodgkin lymphoma or non-Hodgkin-lymphoma—evaluation by using antimüllerian hormone and retrieved oocytes.
      ). Low ovarian responce was also suggested in a small group of BRCA1 carriers (
      • Oktay K.
      • Kim J.Y.
      • Barad D.
      • Babayev S.N.
      Association of BRCA1 mutations with occult primary ovarian insufficiency: a possible explanation for the link between infertility and breast/ovarian cancer risks.
      ). Differences in ovarian response among different cancer types should be further evaluated, because other studies have indicated that there is no difference in response between cancer patients and control subjects (
      • Pal L.
      • Leykin L.
      • Schifren J.L.
      • Isaacson K.B.
      • Chang Y.C.
      • Nikruil N.
      • et al.
      Malignancy may adversely influence the quality and behaviour of oocytes.
      ,
      • Knopman J.M.
      • Noyes N.
      • Talebian S.
      • Krey L.C.
      • Grifo J.A.
      • Licciardi F.
      Womenwith cancer undergoing ART for fertility preservation: a cohort study of their response to exogenous gonadotropins.
      ,
      • Quintero R.B.
      • Helmer A.
      • Huang J.Q.
      • Westphal L.M.
      Ovarian stimulation for fertility preservation in patients with cancer.
      ).

       Ovarian stimulation regimens in breast cancer patients

      The choice of ovarian stimulation regimen in patients with breast cancer is particularly complex. Because estrogen has been implicated in the pathogenesis of breast cancer, concerns that elevated E2 serum levels during ovarian stimulation could propagate breast cancer cell proliferation have led to the development of several alternative approaches. Natural-cycle IVF avoids supraphysiologic E2 levels but yields unacceptably low numbers of oocytes for cancer patients. Letrozole is an aromatase inhibitor that effectively suppresses plasma levels of E2 and is commonly used in the treatment of postmenopausal women with breast cancer. When used in conjunction with exogenous gonadotropins, multiple follicle development occurs without a significant rise in serum E2 (
      • Oktay K.
      • Buyuk E.
      • Libertella N.
      • Akar M.
      • Rosenwaks Z.
      Fertility preservation in breast cancer patients: a prospective controlled comparison of ovarian stimulation with tamoxifen and letrozole for embryo cryopreservation.
      ). In a group of 79 patients that underwent ovarian stimulation with gonadotropins and letrozole, the hazard ratio for recurrence was not increased and survival was not compromised (
      • Azim A.A.
      • Costantini-Ferrando M.
      • Oktay K.
      Safety of fertility preservation by ovarian stimulation with letrozole and gonadotropins in patients with breast cancer: a prospective controlled study.
      ).
      Tamoxifen is a nonsteroidal antiestrogen that has proven efficacy as both an ovulation induction agent and a potent suppressor of breast carcinogenensis. It can be used in doses of 20–60 mg to stimulate the ovaries, and has been reported to yield greater numbers of oocytes when exogenous gonadotropins are added to stimulation protocol (
      • Oktay K.
      • Buyuk E.
      • Libertella N.
      • Akar M.
      • Rosenwaks Z.
      Fertility preservation in breast cancer patients: a prospective controlled comparison of ovarian stimulation with tamoxifen and letrozole for embryo cryopreservation.
      ). Tamoxifen has also been used for protection against high serum E2 levels during conventional ovarian stimulation protocol in breast cancer patients. Breast cancer patients underwent long GnRH-agonist or antagonist ovarian stimulation for FP and were cotreated with tamoxifen (20 mg) throughout stimulation, yielding a mean of 8.4 and 10.5 eggs, respectively, indicating that that coadministration of tamoxifen during conventional ovarian stimulation does not interfere with response. Long-term follow up of this patient cohort (2–9 years) suggested that the risk of cancer recurrence and late mortality are not increased by use of this stimulation strategy, supporting the observation that tamoxifen provides protection of the breast in the presence of high E2 levels in nonmenopausal patients (
      • Meirow D.
      • Shulman A.
      • Levron J.
      • Maman E.
      • Farber B.
      • Kaufman B.
      • et al.
      Fertility preservation using ART and embryo cryopreservation prior to chemotherapy in breast cancer patients. New and safe protocol for ovarian stimulation.
      ).

       Outcomes in Embryo Banking

      Although there is substantial clinical experience with embryo cryopreservation across ART centers in noncancer patients, there is a paucity of outcome data on embryo cryopreservation in cancer patients. A European registry study reported fewer oocytes and embryos with increasing maternal age in cancer patients and, using a German IVF registry, calculated estimated 2-pronuclei–stage survival to be 80%, pregnancy rate 20% per embryo transfer (ET), and live birth rate 15% per ET (
      • Lawrenz B.
      • Jauckus J.
      • Kupka M.
      • Strowitzki T.
      • von Wolff M.
      Efficacy and safety of ovarian stimulation before chemotherapy in 205 cases.
      ). Small case series reporting delivery rates after embryo cryopreservation in cancer patients have been published reporting that 50% of patients ultimately had live births resulting from their cryopreserved embryos (
      • Robertson A.D.
      • Missmer S.A.
      • Ginsburg E.S.
      Embryo yield after in vitro fertilization in women undergoing embryo banking for fertility preservation before chemotherapy.
      ,
      • Michaan N.
      • Ben-David G.
      • Ben-Yosef D.
      • Almog B.
      • Many A.
      • Pauzner D.
      • et al.
      Ovarian stimulation and emergency in vitro fertilization for fertility preservation in cancer patients.
      ). Although it is common to estimate frozen embryo implantation potential with the use of data from the age-matched infertile population, it is possible that implantation rates in the cancer population may be higher, because they are presumably fertile at the time of embryo cryopreservation. Larger series are needed to determine whether this is indeed the case.

       Outcomes in Oocyte Banking

      Although the use of oocyte cryopreservation has expanded rapidly in recent years it was still considered to be experimental by the ASRM until October 2012. There is evidence of increasing efficacy and growing acceptance for this technology, with >50% of ART clinics in the United States currently offering oocyte cryopreservation as a means of FP for patients with and without cancer (
      • Rudick B.
      • Opper N.
      • Paulson R.
      • Bendikson K.
      • Chung K.
      The status of oocyte cryopreservation in the United States.
      ,
      • Cobo A.
      • Meseguer M.
      • Remohí J.
      • Pellicer A.
      Use of cryo-banked oocytes in an ovum donation programme: a prospective, randomized, controlled, clinical trial.
      ). Most published reports describe outcomes related to efficiency and safety of the technology with donor oocytes or when used as an adjunct to IVF in the infertile population. In a survey of ART clinics in the United States, the median reported fertilization rate of thawed oocytes with the use of ICSI was 67%, and the median reported pregnancy rate per cycle was 33% (
      • Rudick B.
      • Opper N.
      • Paulson R.
      • Bendikson K.
      • Chung K.
      The status of oocyte cryopreservation in the United States.
      ). The largest review of perinatal outcomes after oocyte cryopreservation analyzed outcomes in 936 live births and found that the rate of congenital abnormalities (1.3%) was not increased compared with the rate in spontaneously conceived infants (
      • Noyes N.
      • Porcu E.
      • Borini A.
      Over 900 oocyte cryopreservation babies born with no apparent increase in congenital anomalies.
      ). Although these results are not specific to the cancer population, they justify FP using this technology in cancer patients, and the recent removal of the “experimental” label should improve accessibility and increase the likelihood of insurance coverage for oocyte cryopreservation.

       Embryo and Oocyte Banking in Cancer Survivors

      Some cancer patients may present for fertility counseling after they have completed their cancer therapy. In survivors who have resumed regular menses, chemotherapy-induced ovarian injury has been evidenced by elevated FSH levels and reduced levels of AMH, inhibin B, and antral follicle counts, all indicative of a shortened reproductive lifespan, eventually leading to premature ovarian failure (
      • Su H.I.
      • Sammel M.D.
      • Green J.
      • Velders L.
      • Stankiewicz C.
      • Matro J.
      • et al.
      Antimullerian hormone and inhibin B are hormone measures of ovarian function in late reproductive-aged breast cancer survivors.
      ,
      • Su H.I.
      • Chung K.
      • Sammel M.D.
      • Gracia C.R.
      • DeMichele A.
      Antral follicle count provides additive information to hormone measures for determining ovarian function in breast cancer survivors.
      ,
      • Gracia C.R.
      • Sammel M.D.
      • Freeman E.
      • Prewitt M.
      • Carlson C.
      • Ray A.
      • et al.
      Impact of cancer therapies on ovarian reserve.
      ). In anticipation of this shortened window of reproductive potential, embryo or oocyte cryopreservation may be offered to these young patients with diminished ovarian reserve if they are not yet ready to conceive. However, on many occasions the yield is low owing to severely compromised ovarian reserve.

      Ovarian tissue cryopreservation

      Ovarian tissue cryopreservation is an alternative strategy for FP, indicated in patients who have a high risk of ovarian failure after cancer treatment. Although it is considered to be investigational by the ASRM, its distinct advantages have led to increasing use of this technology and promising results in recent years. In the recently revised Practice Committee Opinion, ovarian tissue cryopreservation and its current status were not addressed (
      Practice Committee of American Society for Reproductive Medicine; Practice Committee of Society for Assisted Reproductive Technology. Mature oocyte cryopreservation: a guideline.
      ). It is the only option available for prepubertal girls, and may be the best option for patients who should start their chemotherapy or radiation straightaway. Surgical removal of ovarian tissue causes no delay in cancer treatment initiation and yields an abundance of primordial follicles. In young cancer patients who have recently been exposed to chemotherapy treatments, ovarian tissue cryopreservation is the only option to preserve fertility, because it mainly preserves primordial follicles, which are not subject to the deleterious effects of chemotherapy on growing and mature follicles. At Chaim Sheba Medical Center, about 50% of patients have already been exposed to chemotherapy before ovarian tissue harvesting.

       Techniques for Ovarian Tissue Cryopreservation and Transplantation

      More than 25 live births with cryopreserved ovarian tissue have been reported thus far, all as a result of orthotopic (pelvic) transplantation of thawed pieces of ovarian cortex. A comprehensive review described in detail the first 13 live births achieved in ten women who underwent transplantation of cryopreserved ovarian tissue (
      • Donnez J.
      • Silber S.
      • Andersen C.Y.
      • Demeestere I.
      • Piver P.
      • Meirow D.
      • et al.
      Children born after autotransplantation of cryopreserved ovarian tissue. a review of 13 live births.
      ). The amount of ovarian tissue removed varied from cortical biopsies measuring ∼1.0 × 0.5 cm to removal of an entire ovary. Techniques used to remove small biopsy segments from the ovaries are not recommended in current practice, because many follicles are lost during freezing/thawing/transplantation procedures (
      • Meirow D.
      • Nugent S.F.
      • Schenker J.G.
      • Gosden R.G.
      • Rutherford A.J.
      A laparoscopic technique for obtaining ovarian cortical biopsies for fertility conservation in cancer patients.
      ).
      Immature egg retrieval can be performed under transvaginal ultrasound guidance before laparoscopy for IVM. Additionally, when ovarian tissue is prepped for cryopreservation by removing the medulla and dividing the cortical tissue into 5 × 10-mm pieces (
      • Meirow D.
      • Baum M.
      • Yaron R.
      • Levron J.
      • Hardan I.
      • Schiff E.
      • et al.
      Ovarian tissue cryopreservation in hematologic malignancy: ten years’ experience.
      ), oocyte cumulus complexes from antral follicles may also be collected. This “combined procedure” provides a possible second means to potential pregnancy in addition to the future transplantation of cryopreserved tissue (
      • Domingo J.
      • Guillén V.
      • Ayllón Y.
      • Martínez M.
      • Muñoz E.
      • Pellicer A.
      • et al.
      Ovarian response to controlled ovarian hyperstimulation in cancer patients is diminished even before oncological treatment.
      ,
      • Revel A.
      • Laufer N.
      • Ben Meir A.
      • Lebovich M.
      • Mitrani E.
      Micro-organ ovarian transplantation enables pregnancy: a case report.
      ). However, it should be used only in patients who were not exposed to chemotherapy during the previous 6 months owing to concerns about the effects of chemotherapy on maturing follicles.
      To date, all reported live births from cryopreserved ovarian tissue used slow-freezing protocols, although vitrification protocols have been described (
      • Kagawa N.
      • Silber S.
      • Kuwayama M.
      Successful vitrification of bovine and human ovarian tissue.
      ,
      • Sheikhi M.
      • Hultenby K.
      • Niklasson B.
      • Lundqvist M.
      • Hovatta O.
      Clinical grade vitrification of human ovarian tissue: an ultrastructural analysis of follicles and stroma in vitrified tissue.
      ). Preliminary in vitro studies comparing slow freezing and vitrification have yielded conflicting results. Whereas some investigators demonstrated excellent oocyte viability from vitrified ovarian strips and their ability to resume folliculogenesis (
      • Amorim C.A.
      • Dolmans M.M.
      • David A.
      • Jaeger J.
      • Vanacker J.
      • Camboni A.
      • et al.
      Vitrification and xenografting of human ovarian tissue.
      ), others reported fewer primordial follicles and lower AMH production from vitrified compared with slow-frozen human ovaries (
      • Oktem O.
      • Alper E.
      • Balaban B.
      • Palaoglu E.
      • Peker K.
      • Karakaya C.
      • et al.
      Vitrified human ovaries have fewer primordial follicles and produce less antimüllerian hormone than slow-frozen ovaries.
      ).
      The primary goal of ovarian tissue storage is to reimplant a few thawed cortical strips into the patient (i.e., autotransplantation) once the patient has completed cancer treatment, is disease free, and desires pregnancy. Pieces of ovarian cortex can be grafted to orthotopic (pelvis) or heterotopic (subcutaneous) sites, each having distinct advantages and disadvantages. Despite the significantly more invasive nature of orthotopic transplantation, its proven efficacy in restoration of ovarian function and fertility makes it the favored approach. Ideally, the graft should be placed on the remaining ovary but if this is not possible, orthotopic placement in the pelvis is an effective option. This can be performed either by transplantation of thawed ovarian strips bellow the cortex, decortication of the atrophic in situ ovary followed by reimplantation of thawed ovarian pieces directly on to the ovarian medulla or creation of a peritoneal window adjacent to the ovarian hilum. Large strips (8–10 × 5 mm) and small cubes (2 × 2 mm) were both shown to restore ovarian endocrine function effectively after orthotopic reimplantation (Fig. 1). Transplantation of ultrathin (350 μm) slivers of thawed ovarian tissue termed “ovarian micro-organs” has also been described, which achieved a successful live birth in a patient who previously failed to achieve pregnancy when conventional ovarian strips were used (
      • Meirow D.
      • Baum M.
      • Yaron R.
      • Levron J.
      • Hardan I.
      • Schiff E.
      • et al.
      Ovarian tissue cryopreservation in hematologic malignancy: ten years’ experience.
      ).
      Figure thumbnail gr1
      Figure 1Orthotopic reimplantation of thawed ovarian cortical fragments by different surgical approaches. (A) Large ovarian cortical strips 0.5 × 1.0 cm prepared for transplantation. (B) Transplantation of large ovarian strips beneath the cortex of atrophic ovary (reprinted with permission from J. Dor and D. Meirow). (C) Orthotopic transplantation of large ovarian strip on the broad ligament. (reprinted with permission from S. Silber and D. Meirow). (D) Insertion of ultrathin ovarian fragment into peritoneal pocket
      (reprinted with permission from F. Azem and A. Amit).

       Outcomes of Ovarian Tissue Grafting

      Endocrine indicators that the ovarian graft is functioning typically rise a few months after transplantation. The average time reported to first menses was 4.7 months, and the duration of graft functioning has varied from 9 to >86 months (
      • Janse F.
      • Donnez J.
      • Anckaert E.
      • de Jong F.H.
      • Fauser B.C.
      • Dolmans M.M.
      Limited value of ovarian function markers following orthotopic transplantation of ovarian tissue after gonadotoxic treatment.
      ). Pregnancies and live birth after transplantation were reported by natural conception (
      • Donnez J.
      • Dolmans M.M.
      • Demylle D.
      • Jadoul P.
      • Pirard C.
      • Squifflet J.
      • et al.
      Livebirth after orthotopic transplantation of cryopreserved ovarian tissue.
      ) or after IVF (
      • Meirow D.
      • Levron J.
      • Eldar-Geva T.
      • Hardan I.
      • Fridman E.
      • Zalel Y.
      • et al.
      Pregnancy after transplantation of cryopreserved ovarian tissue in a patient with ovarian failure after chemotherapy.
      ). Of reported live births from orthotopic autotransplantation in cancer patients, the time interval between reimplantation and first pregnancy ranged from 6 to 11 months. There are no reports of adverse pregnancy outcomes or congenital abnormalities after ovarian tissue transplantation.
      The effectiveness of the procedure is difficult to estimate, because these reports are coming from different centers, patients were evaluated by different groups, and different techniques were used for collecting, freezing, and transplantation of ovarian tissue. There are insufficient data on the number of failed transplantations performed and publications mostly represent successes. Therefore, it is not possible to estimate overall success rates nor to evaluate the “effectiveness of techniques” and factors used to improve transplantation outcome. However, these results are important, because they contribute clinical outcome data indicating that ovarian tissue transplantation is a successful procedure. At Sheba Medical Center, stored ovarian tissue was transplanted in seven patients suffering from ovarian failure after chemotherapy (aged 23–42 eyars). Spontaneous menstruation returned in all patients. All patients underwent IVF cycles (1–11 cycles per patient), and oocytes were successfully retrieved in 70% of cycles, the number of oocytes collected was 1–2 per cycle, and fertilization rates were high. Four of the seven patients conceived (57%) (

      Meirow D, Raanani H, Brengauz M, Dor J. Results of one center indicate that transplantation of thawed ovarian tissue is effective. Repeated IVF reveals good egg quality and high pregnancy rate. Meeting of the European Society of Human Reproduction and Embryology (ESHRE), Istanbul, Turkey, 2012.

      ).

       Potential Malignant Cell Contamination in Cryopreserved Ovarian Tissue

      One of the main concerns of transplanting thawed ovarian tissue in cured cancer patients is the potential for reintroduction of malignant cells which could propagate cancer recurrence. Preoperative imaging with ultrasonography and computerized tomographic scan can identify patients with overt ovarian involvement and prevent unnecessary laparoscopies. Routine histology is used but commonly does not identify malignant contamination of the tissue. In a study of 18 leukemia patients—six with chronic myeloid leukemia (CML) and twelve with acute lymphoblastic leukemia (ALL)—no malignant cells were seen by histologic and immunohistochemical analysis. However, by highly sensitive reverse-transcription polymerase chain reaction (RT-PCR), molecular markers for leukemic cells were positive in 2 of 6 CML patients and 7 of 10 evaluable ALL patients (
      • Dolmans M.M.
      • Marinescu C.
      • Saussoy P.
      • van Langendonckt A.
      • Amorim C.
      • Donnez J.
      Reimplantation of cryopreserved ovarian tissue from patients with acute lymphoblastic leukemia is potentially unsafe.
      ). The clinical significance of positive PCR in ovarian tissue is not known. Although there are as yet no reports of cancer recurrences in human recipients of transplanted ovarian tissue, animal studies have demonstrated intraperitoneal growth of leukemic masses after transplantation of ovarian tissue from ALL patients (
      • Dolmans M.M.
      • Marinescu C.
      • Saussoy P.
      • van Langendonckt A.
      • Amorim C.
      • Donnez J.
      Reimplantation of cryopreserved ovarian tissue from patients with acute lymphoblastic leukemia is potentially unsafe.
      ). Therefore, there is significant concern about the safety of ovarian tissue grafting in patients with a history of leukemia. However, RT-PCR can detect evidence of leukemic cells in patients with CML and can lead to the decision to avoid tissue grafting (
      • Meirow D.
      • Hardan I.
      • Dor J.
      • Fridman E.
      • Elizur S.
      • Ra’anani H.
      • et al.
      Searching for evidence of disease and malignant cell contamination in ovarian tissue stored from hematologic cancer patients.
      ). Alternatively, if highly sensitive RT-PCR does not show evidence of leukemic cells in the stored ovarian tissue, transplantation can be performed safely, as was done in another patient with CML who underwent transplantation of ovarian tissue collected before bone marrow transplantation (

      Meirow D, Raanani H, Brengauz M, Dor J. Results of one center indicate that transplantation of thawed ovarian tissue is effective. Repeated IVF reveals good egg quality and high pregnancy rate. Meeting of the European Society of Human Reproduction and Embryology (ESHRE), Istanbul, Turkey, 2012.

      ).
      To optimize the safety of storage and transplantation of ovarian tissue in patients with leukemia we follow the protocol depicted in Figure 2. Paitents with AML or ALL need urgent treatment and IVF is not an option. At this time numerous leukemic cells are present in the bone marrow and the blood. Because chemotherapy for AML has no significant effect on ovarian reserve (
      • Meirow D.
      • Biederman H.
      • Anderson R.A.
      • Wallace W.
      Toxicity of chemotherapy and radiation on female reproduction.
      ), we recommend starting chemotherapy immediately without storing ovarian tissue. Only AML patients that subsequently will require additional high-dose chemotherapy and/or bone marrow transplantation are referred for ovarian tissue harvesting, owing to high sterilization risks. At this stage, because the blood is clean from leukemic cells and in most cases there are no leukemic cells in the bone marrow, the chance of finding leukemic cells in the ovary is vastly reduced. In any case, before reimplantation, the ovarian tissue is tested for minimal residual disease using the most sensitive methods. In ALL patients, the first chemotherapy courses also are typically not sterilizing. Collecting ovarian tissue may be performed after a few cycles of chemotherapy when testing indicates no evidence of leukemic cells in the blood. In contrast, mature or immature egg collection is not recommended at this stage, owing to decrease or no response to ovarian stimulation, genetically abnormal oocytes, and deleterious effects on reproductive outcome, including high abortion and malformation rates, as indicated by animal studies (
      • Meirow D.
      • Schiff E.
      Appraisal of chemotherapy effects on reproductive outcome according to animal studies and clinical data.
      ,
      • Kujjo L.L.
      • Chang E.A.
      • Pereira R.J.
      • Dhar S.
      • Marrero-Rosado B.
      • Sengupta S.
      • et al.
      Chemotherapy-induced late transgenerational effects in mice.
      ,
      • Bar-Joseph H.
      • Ben-Aharon I.
      • Rizel S.
      • Stemmer S.M.
      • Tzabari M.
      • Shalgi R.
      Doxorubicin-induced apoptosis in germinal vesicle (GV) oocytes.
      ).
      Figure thumbnail gr2
      Figure 2Different approaches for fertility preservation in young female patients diagnosed with acute leukemia. AML = acute myeloid leukemia; ALL = acute lymphoblastic leukemia. *See the text for explanations of why not recommended.
      Several small studies have evaluated ovarian tissue from patients with breast cancer for the presence of malignant cell contamination with the use of routine histology and immunohistochemistry. Analysis of portions or the entire ovarian cortex did not detect breast cancer cells (
      • Sánchez-Serrano M.
      • Novella-Maestre E.
      • Roselló-Sastre E.
      • Camarasa N.
      • Teruel J.
      • Pellicer A.
      Malignant cells are not found in ovarian cortex from breast cancer patients undergoing ovarian cortex cryopreservation.
      ,
      • Rosendahl M.
      • Timmermans Wielenga V.
      • Nedergaard L.
      • Kristensen S.G.
      • Ernst E.
      • Rasmussen P.E.
      • et al.
      Cryopreservation of ovarian tissue for fertility preservation: no evidence of malignant cell contamination in ovarian tissue from patients with breast cancer.
      ). In seven patients suffering from Ewing sarcoma, there was no evidence of sarcoma cells in the ovaries from pathologic/molecular studies. However, in one patient, RT-PCR showed the specific translocation marker unique for the disease (
      • Abir R.
      • Feinmesser M.
      • Yaniv I.
      • Fisch B.
      • Cohen I.J.
      • Ben-Haroush A.
      • et al.
      Occasional involvement of the ovary in Ewing sarcoma.
      ). All of these results emphasize that ovarian tissue should be examined for traces of malignancy at both pathologic and molecular levels before the grafting. However, for most cancers (solid and hematologic) there are still no reliable molecular markers.

      Alternative approaches to use of cryopreserved ovarian tissue

      Alternative methods for use of the cryopreserved tissue are theoretically possible: IVM of follicles isolated from the ovarian cortex to avoid transmission of malignant cells; and whole-ovary vascular transplantation to reduce follicular loss due to tissue ischemia. However, the efficacy of these methods has not yet been proven in humans. Studies of follicle IVM with the use of a bioengineered culture system have demonstrated the ability to develop secondary follicles to antral-stage follicles with steroidogenic competence (
      • Xu M.
      • Barrett S.L.
      • West-Farrell E.
      • Kondapalli L.A.
      • Kiesewetter S.E.
      • Shea L.D.
      • et al.
      In vitro grown human ovarian follicles from cancer patients support oocyte growth.
      ). This technology has not been reported to produce a human live birth and can not be offered as FP technique to patients. Whole intact ovary transplantation might avoid the ischemia time associated with graft revascularization. However, there are no reports of success from whole-ovary cryopreservation, and transplantation is a technically difficult surgical procedure. Only a single live birth has been reported so far after transplantation of a fresh (not cryopreserved) ovary (
      • Silber S.J.
      • Grudzinskas G.
      • Gosden R.G.
      Successful pregnancy after microsurgical transplantation of an intact ovary.
      ). In contrast, autotransplantation of cryopreserved pieces of ovarian tissue is a relatively robust procedure that can be repeated over time, has relatively long graft survival, and has yielded the largest cohort of live births, making it the favored approach at this time.

      Conclusion

      It is estimated that more than one-third of young women exposed to cancer therapy develop premature ovarian failure. As increasing numbers of these women survive their cancer and many desire their own biologic offspring, fertility preservation has emerged as an important part of optimizing quality of life among survivors. Because many young women with cancer present with unique challenges and concerns, the optimal approach to fertility preservation must be individualized, and embryo cryopreservation is certainly not the ideal choice for all patients. The data presented herein suggest that, although embryo cryopreservation is still considered to be the “gold standard,” oocyte cryopreservation can be an effective means of fertility preservation for cancer patients facing potentially gonadotoxic treatments. Ovarian tissue cryopreservation is a promising technique, and not infrequently it is the only option that can be offered. The accumulated experience reported in this paper adds significantly to the available data on clinical outcomes and challenges the concept that FP techniques in cancer patients should be labeled “experimental.”

      References

      1. Altekruse SF, Kosary CL, Krapcho M, Neyman N, Aminou R, Waldron W, et al. SEER cancer statistics review, 1975–2007. Bethesda, MD: National Cancer Institute. Available at: http://seer.cancer.gov/csr/1975_2007/. Last accessed March 8, 2013.

      2. National Center for Health Statistics. Birth rate for women age 15–44. Available at http://www.cdc.gov/nchs/pressroom/04facts/birthrates.htm. Accessed October, 29, 2008.

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