Anovulation in the prevention of cytotoxic-induced follicular attrition and ovarian failure

Inhibitors of apoptosis protect the ovarian reserve from cyclophosphamide

Cancer therapy can cause off-target effects including ovarian damage, which may result in primary ovarian insufficiency in girls and premenopausal women. Loss of ovarian follicles within the ovarian reserve leads to ovarian endocrine dysfunction and impaired fertility. Cyclophosphamide (CPA), a commonly used chemotherapeutic and immunosuppressant agent, is a gonadotoxic agent that destroys ovarian cells by crosslinking DNA. To protect the ovary against CPA damage, we sought to precisely map the mechanism by which the ovarian reserve is depleted by CPA. We found that CPA specifically depletes primordial follicles without affecting primary and secondary follicles in three independent murine strains (CD-1, C57BL/6J and BALB/cJ) in vivo. We directly tested the effect of the active metabolite of CPA, 1 μM 4-hydroxyperoxycyclophophamide (4-HC), in vitro and confirmed the loss of primordial oocytes but no change in the number of primary and secondary follicles. We demonstrated that phospho-AKT (p-AKT) and cleaved PARP (cPARP) are present in primordial oocytes 3 days after CPA injection, consistent with the role of these markers as part of the apoptotic cascade. Interestingly, p-AKT positive primordial oocytes co-expressed cPARP. Treatment of animals with specific inhibitors of apoptotic pathway components, ETP46464 and CHK2, blocked 4-HC‒induced DNA damage in vitro. These data suggest that CPA targets primordial germ cells in the ovarian reserve by stimulating apoptosis pathways. Adjuvant therapies to protect primordial germ cells from the off-target effects of CPA may reduce the risk of POI.

Ovarian protection with gonadotropin-releasing hormone agonists during chemotherapy in cancer patients: From biological evidence to clinical application

Survivorship issues are an area of crucial importance to be addressed as early as possible by all health care providers dealing with cancer patients. In women diagnosed during their reproductive years, the possible occurrence of chemotherapy-induced premature ovarian insufficiency (POI) is of particular concern being associated with important menopause-related symptoms, psychosocial issues as well as infertility. Temporary ovarian suppression by administering a gonadotropin-releasing hormone agonist (GnRHa) during chemotherapy has been studied to reduce the gonadotoxic impact of chemotherapy thus diminishing the chance of developing POI. Despite more than 30 years of research in both preclinical and clinical settings, the performance of this strategy has remained highly debated until recently. In particular, the potential mechanisms of action for the protective effects of GnRHa during chemotherapy are still not clearly identified. Nevertheless, important novel research efforts in the field have better elucidated the role of this option that is now endorsed for clinical use by several guidelines. This manuscript aims at providing an extensive overview of the literature on the use of temporary ovarian suppression with GnRHa during chemotherapy in cancer patients by addressing its biological rationale, the available preclinical and clinical evidence as well as the still existing grey zones in this field that future research efforts should address.

Low-dose metronomic delivery of cyclophosphamide is less detrimental to granulosa cell viability, ovarian function, and fertility than maximum tolerated dose delivery in the mouse

Chemotherapy can cause early menopause or infertility in women and have a profound negative impact on the quality of life of young female cancer survivors. Various factors are known to influence the risk of chemotherapy-induced ovarian failure, including the drug dose and treatment duration; however, the scheduling of dose administration has not yet been evaluated as an independent risk factor. We hypothesized that low-dose metronomic (LDM) chemotherapy scheduling would be less detrimental to ovarian function than the traditional maximum tolerated dose (MTD) strategy. In vitro, MTD cyclophosphamide exposure resulted in decreased proliferation and increased granulosa cell apoptosis, while cells treated with LDM cyclophosphamide were not different from untreated controls. Treatments of MTD cyclophosphamide induced high levels of follicle atresia and enhanced follicle recruitment in mice. In contrast, LDM delivery of an equivalent dose of cyclophosphamide reduced growing follicle numbers, but was not associated with higher levels of follicle atresia or recruitment. MTD cyclophosphamide induced significant vascular disruption and DNA damage in vivo, while LDM chemotherapy with equal cumulative amounts of cyclophosphamide was not different from controls. MTD chemotherapy also had a negative effect on mouse-fertility outcomes. Our findings suggest that LDM scheduling could potentially minimize the long-term effects of cyclophosphamide on female fertility by preventing follicle depletion from enhanced activation.

Orthotopic transplantation of cryopreserved mouse ovaries and gonadotrophin releasing hormone analogues in the restoration of function following chemotherapy-induced ovarian damage

Therapy advances are constantly improving survival rates of cancer patients, however the toxic effects of chemotherapy drugs can seriously affect patients' quality of life. In women, fertility and premature ovarian endocrine dysfunction are of particular concern. It is urgently we find methods to preserve or reconstruct ovarian function for these women. This study compares GnRHa treatment with ovarian tissue cryopreservation and orthotopic transplantation in a chemotherapy-induced ovarian damage murine model. 56 inbred Lewis rats were divided into 4 treatment groups: Saline control (group I); cyclophosphamide only (group II); cyclophosphamide plus GnRHa (group III); cyclophosphamide and grafting of thawed cryopreserved ovaries (group IV). Body weight, estrous cycle recovery time, ovarian weight, morphology and follicle count, as well as breeding and fertility were compared among groups. Only group IV was able to restore to normal body weight by the end of the observation period and resumed normal estrous cycles in a shorter time compared to other treatment groups. There was a decrease in primordial follicles in all treatment groups, but group III had the greatest reduction. Although, there was no difference in pregnancy, only one animal littered normal pups in group II, none littered in group III and four littered in group IV. Thus, cryopreservation and orthotopic transplantation of ovarian tissue can restore the fertility of rats subjected to chemotherapy in a manner that is superior to GnRHa treatment. We also observed increased rates of hepatic, splenic and pulmonary haemorrhage in group III, suggesting there may be synergistic toxicity of GnRHa and cyclophosphamide.

Gonadotrophin-releasing hormone agonists for fertility preservation: unraveling the enigma?

STUDY QUESTION

Can gonadotrophin-releasing hormone agonists (GnRH-a) preserve long-term fertility when administered prior to and concomitantly with chemotherapy?

SUMMARY ANSWER

GnRH-a display a differential protective effect on fertility, depending upon the specific chemotherapy-induced mechanism of ovarian injury.

WHAT IS KNOWN ALREADY

The role of GnRH-a in fertility preservation has been constantly debated and their use is considered experimental due to conflicting clinical evidence and paucity of data regarding their mechanism for ovarian protection.

STUDY DESIGN, SIZE, DURATION

In vivo model: 7-8 weeks old imprinting control region (ICR) mice were injected with GnRH-a (Leuprolide-acetate) or saline prior to and concomitantly with cyclophosphamide, doxorubicin or saline and sacrificed at various time-points on a longitudinal follow-up; 24 h (n = 36), 1 week (n = 40), 1 month (n = 36) and 9 months (n = 66) post chemotherapy treatment. Blood samples were drawn on Day 0 and on a monthly basis after chemotherapy treatment. On the day of sacrifice, blood samples were drawn and ovaries excised and processed for either immunohistochemistry (IHC), protein or RNA extraction. In vitro model: 21-23 days old Wistar-derived rats were sacrificed, their ovaries excised and primary granulosa cells (PGC) were either isolated for in vitro culture, or processed for immunofluorescence (IF) as well as for protein or RNA extraction.

MATERIALS, SETTING, METHODS

Ovarian reserve was estimated by serial measurements of serum anti-mullerian hormone (AMH), quantified by the AMH Gen II ELISA assay. Ovarian AMH and phosphorylated Akt (pAkt) were detected by immunoblotting. Vascular endothelial growth factor (VEGF) was measured by quantitative PCR. Ovarian GnRH receptor (GnRHR), AMH and CD34 were visualized by IHC, and apoptosis was evaluated using TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labeling (TUNEL).

MAIN RESULTS AND THE ROLE OF CHANCE

Cyclophosphamide-induced ovarian injury caused a prompt decrease in AMH level (P < 0.01) and a further long-term decline in serum AMH (P = 0.017), indicating damage to the ovarian reserve. Pretreatment with GnRH-a diminished AMH-decrease (P < 0.05) and maintained serum AMH level in the long run (P < 0.05). Doxorubicin-exerted ovarian-vascular-injury is also displayed by an acute increase in ovarian VEGF level (P < 0.05) and a sustained decrease in serum AMH level (P < 0.001). This was followed by ovarian recovery manifested by increased neovascularization. GnRH-a delayed the recovery in AMH level and decreased the level of VEGF (P < 0.001), thus interfering with the vascular recovery subsequent to doxorubicin-induced vascular damage.

LIMITATIONS, REASONS FOR CAUTION

To portray the differential mechanism of each chemotherapy, cyclophosphamide and doxorubicin were given separately, whereas most of the clinical protocols include several types of chemotherapies. Thus, future study should explore a prospective evaluation of various chemotherapies, as well as combined chemotherapeutic protocols.

WIDER IMPLICATIONS OF THE FINDINGS

Our study demonstrates that different chemotherapy agents affect the ovary via diverse mechanisms and thus the administration of GnRH-a concomitantly, could be beneficial to a subpopulation of patients treated with cyclophosphamide-based protocols.

STUDY FUNDING/COMPETING INTERESTS

This work was partially supported by a grant from the Israel Science Foundation (ISF) to I.B.-A. The authors have no conflict of interest to disclose.

Tocotrienol preserves ovarian function in cyclophosphamide therapy

INTRODUCTION

Cyclophosphamide (CPA) chemotherapy leads to ovarian failure and infertility. Tocotrienol (T3) is an antioxidant and anti-inflammatory agent. The role of T3 in ovarian protection throughout chemotherapy remains unclear.

AIM

To investigate the role of T3 in the preservation of female fertility in CPA treatment.

METHOD

Sixty female mice were divided into five treatment groups, namely, normal saline, corn oil only, T3 only, CPA and CPA + T3. The treatment was given for 30 days, followed by administration of gonadotrophin to induce ovulation. After killing, both ovaries were collected and examined histologically.

RESULTS

There was significant reduction in ovarian size in the CPA group compared with the normal group (CPA versus normal, mean area ± SD; 0.118 ± 0.018 vs. 0.423 ± 0.024 cm(2); p ≤ 0.005), whilst concurrent administration of T3 with CPA leads to conservation of ovarian size (CPA + T3 vs. CPA, mean area ± SD; 0.285 ± 0.032 vs. 0.118 ± 0.018 cm(2); p ≤ 0.005). Ovaries in CPA group showed abnormal folliculogenesis with accompanied reduced ovulation rate, follicular oedema, increased vascularity and inflammatory cell infiltration. These changes were reversed by concurrent T3 administration.

CONCLUSION

Co-administration of T3 with CPA confers protection of ovarian morphology and function in vivo. These findings contribute to the further elucidation of CPA effect on ovary and suggest the potential of T3 use in preserving fertility in chemotherapy.

Cyclophosphamide triggers follicle activation and "burnout"; AS101 prevents follicle loss and preserves fertility

Premature ovarian failure and infertility are major side effects of chemotherapy treatments in young cancer patients. A more thorough understanding of the mechanism behind chemotherapy-induced follicle loss is necessary to develop new methods to preserve fertility in these patients. We show that the alkylating agent cyclophosphamide (Cy) activates the growth of the quiescent primordial follicle population in mice, resulting in loss of ovarian reserve. Despite the initial massive apoptosis observed in growing, though not in resting, follicles of Cy-treated mice, differential follicle counts demonstrated both a decrease in primordial follicles and an increase in early growing follicles. Immunohistochemistry showed that granulosa cells were undergoing proliferation. Analysis of the phosphatidylinositol 3-kinase signaling pathway demonstrated that Cy increased phosphorylation of proteins that stimulate follicle activation in the oocytes and granulosa cells. Coadministration of an immunomodulator, AS101, reduced follicle activation, thereby increasing follicle reserve and rescuing fertility after Cy, and also increased the efficacy of Cy against breast cancer cell lines. These findings suggest that the mechanism in Cy-induced loss of ovarian reserve is accelerated primordial follicle activation, which results in a "burnout" effect and follicle depletion. By preventing this activation, AS101 shows potential as an ovarian-protective agent, which may be able to preserve fertility in female cancer patients.

Mechanistic action of mesenchymal stem cell injection in the treatment of chemically induced ovarian failure in rabbits

BACKGROUND

No curative treatment is known for primary ovarian failure; however, mesenchymal stem cells (MSCs), through self-renewal and regeneration, push the trial to evaluate their role in the treatment of ovarian failure. The aim of this study was to explore the impact of MSCs on cyclophosphamide (CTX)-induced ovarian failure in rabbits and to clarify the mechanism(s) by which MSCs exert their action.

METHODS

Thirty-five adult female rabbits were injected with CTX to induce ovarian failure. Five rabbits were euthanized after the last injection of CTX for histological examination. The others (30 rabbits) were further subdivided into two groups: group 1 (ovarian failure group, 15 rabbits) received no treatment; group 2 (ovarian failure and MSC recipient group, 15 rabbits) received MSCs isolated from extracted bone marrow of male rabbits.

RESULTS

A decrease of follicle-stimulating hormone and an increase of estrogen and vascular endothelial growth factor (VEGF) levels in the MSC recipient group versus the ovarian failure group were found. Weak caspase-3 expression and +ve proliferating cell nuclear antigen staining after MSC injection were detected. Cytological and histological examinations showed increased follicle numbers with apparent normal structure of ovarian follicles in the MSC recipient group. Moreover, Y chromosome-containing cells from male donors were present within the ovarian tissues in group 2.

CONCLUSIONS

The current study suggests that intravenous injection of MSCs into rabbits with chemotherapy-induced ovarian damage improved ovarian function. MSCs accomplish this function by direct differentiation into specific cellular phenotypes and by secretion of VEGF, which influence the regeneration of the ovary.

Preservation of ovarian function and fertility despite gonadotoxic chemotherapy

The author aims to review the various strategies and avenues for fertility preservation despite gonadotoxic chemotherapy in young women. The recent increase in the survival of young patients has increased the worldwide attempts toward fertility preservation. The currently utilized methods are sperm cryopreservation and banking in male patients, and cryopreservation of embryos, unfertilized oocytes and ovarian tissue, as well as administration of gonadotropin-releasing hormone agonists (GnRH-a) before and during the gonadotoxic chemotherapy in young female patients. For those patients in whom pelvic irradiation is planned, ovariopexy is suggested. Since none of the suggested methods are ideal and none guarantees future fertility, a combination of several methods may optimize patients' chance of fertility preservation. GnRH-a co-treatment may reduce ovarian damage significantly in female patients treated with gonadotoxic chemotherapy. GnRH-a should be considered for women of reproductive age receiving gonadotoxic chemotherapy in addition to assisted reproduction and cryopreservation of embryos, oocytes and ovarian tissue.

Pharmacological interventions for fertility preservation during chemotherapy: a systematic review and meta-analysis

The rate of chemotherapy-induced ovarian failure (CIOF) has been reported as 14-100% and is age- and agent-dependent. The role of GnRH analogs (GnRHa) and oral contraceptives (OC) in the prevention of CIOF is questionable. We performed a systematic review and a meta-analysis of studies assessing the efficacy of hormonal interventions in reducing CIOF in cancer or systemic lupus erythematosus (SLE) patients treated with chemotherapy. MEDLINE, EMBASE, and conference proceedings were searched until October 2009. From 504 potentially relevant references, 21 comparative studies were included for review and analysis. Data were collected to determine the risk ratio (RR) for amenorrhea, FSH levels, pregnancy rate, and biomarkers for ovarian reserve. Sixteen studies (SLE: 4 studies, 85 patients; malignancy: 12 studies, 596 patients) which assessed GnRHa for fertility preservation prior to chemotherapy were included in the meta-analysis. Five studies which evaluated the use of OC were systematically reviewed. Meta-analysis revealed that GnRHa are effective in reducing amenorrhea rates in all patients (RR 0.26, 95% CI 0.14-0.49). Pregnancy rate was higher in the GnRHa arm. The advantage of GnRHa was shown only in observational studies, but not in randomized controlled trials. Biomarkers for ovarian reserve were similar in both arms. Studies evaluating the efficacy of oral contraceptives in preserving ovarian function showed inconclusive results. GnRHa appears to improve menstruation resumption. Nevertheless, randomized prospective trials are less conclusive for their real value in conserving ovarian reserve and pregnancy. Large-scale prospective randomized trials are warranted to evaluate the role of GnRHa in preventing CIOF.

Assessment of fertility protection and ovarian reserve with GnRH antagonist in rats undergoing chemotherapy with cyclophosphamide

BACKGROUND

Reproductive function following chemotherapy is of increasing importance given that survival rates are improving. We assessed whether a gonadotropin-releasing hormone antagonist (GnRHant; cetrorelix) could promote ovarian protection against damage due to chemotherapy.

METHODS

Forty-two female Wistar rats were used in this study. Animals were divided into four groups: group I (n=9) received placebo twice; group II (n=12) received placebo+cyclophosphamide (CPA); group III (n=12) received GnRHant+CPA; and group IV (n=9) received GnRHant+placebo. After medication, the estrous cycle was studied through vaginal smears. Rats were mated, pregnancy was documented and the number of live pups evaluated. Afterwards, rat ovaries were removed and prepared for histological studies. The ovarian cross-sectional area was measured and follicles were counted.

RESULTS

Cyclic changes in vaginal smears were observed in all but one animal after treatment, but group II had a significantly lower rate of animals with proestrus or estrus (p<0.01). The offspring was markedly reduced by CPA treatment (group II, 3.00+/-1.33 pups vs. group I, 11.44+/-0.78 pups, p<0.01) and this effect was partly reversed by pre-treatment with GnRHant (group III, 7.00+/-1.31 pups). The ovarian cross-sectional area was not significantly different between groups, neither was the number of individual follicle types. However, rats in Group IV had a higher total number of ovarian follicles than those in the control group (17.1+/-1.22 vs. 10.9+/-0.70, p<0.05).

CONCLUSION

The use of a GnRHant before CPA chemotherapy provided protection of fertility.

Hormonal strategies for fertility preservation in patients receiving cyclophosphamide to treat glomerulonephritis: a nonrandomized trial and review of the literature

BACKGROUND

Prepubertal patients receiving chemotherapy are relatively resistant to cyclophosphamide-induced germinal cell alterations. We studied the possible protective effect of testosterone and triptorelin to inhibit gonadal activity in men and women receiving cyclophosphamide, respectively.

STUDY DESIGN

Nonrandomized trial.

SETTING & PARTICIPANTS

28 consecutive patients, 11 men and 17 women, from a university medical center with various forms of glomerulonephritis, treated with cyclophosphamide.

INTERVENTION

Men received cyclophosphamide plus testosterone; women were divided into 2 groups: 13 patients (group A) received cyclophosphamide plus triptorelin; 4 (group B) received only cyclophosphamide.

OUTCOMES & MEASUREMENTS

Serum follicle-stimulating hormone (FSH) and serum luteinizing hormone levels and, in addition, sperm counts and testosterone levels in men and estradiol levels in women were measured before and after treatment with cyclophosphamide.

RESULTS

All 10 men became azoospermic or severely oligospermic during treatment; after 12 months, all except 1 had a normal sperm count and FSH levels were normal. In women during cyclophosphamide therapy, amenorrhea occurred in all patients. After cessation of therapy, all women in group A started to menstruate regularly, and at the end of follow-up, ovulatory cycles were demonstrated in all women. Hormone levels showed no significant changes throughout the observation period. Six women conceived, and the pregnancies were brought to term successfully without complications. In group B, all 4 women developed sustained amenorrhea; serum FSH and luteinizing hormone levels at the end of therapy and follow-up were significantly higher with respect to baseline; estradiol levels at the end of follow-up were significantly lower compared with baseline and corresponding values in group A.

LIMITATIONS

The substudy in men is uncontrolled, the substudy in women is nonrandomized.

CONCLUSIONS

The study suggests a protective effect of testosterone and triptorelin against cyclophosphamide-induced gonadal damage in men and women with various forms of kidney disease, respectively.

Gonadotropin-releasing hormone agonist decreases chemotherapy-induced gonadotoxicity and premature ovarian failure in young female patients with Hodgkin lymphoma

OBJECTIVE

To minimize the gonadotoxic effect of chemotherapy by the cotreatment with a GnRH agonistic analogue (GnRH-a).

DESIGN

Prospective nonrandomized study with concurrent and historical controls.

SETTING

University medical center.

PATIENT(S)

One hundred fifteen female patients with Hodgkin lymphoma (HL).

INTERVENTION(S)

Sixty-five patients received a monthly injection of GnRH-a, administered before starting chemotherapy until its conclusion, up to a maximum of 6 months. Thirty-five patients were treated with ABVD and 76 with a procarbazine-containing regimen. This group was compared with a control group of 46 women who were treated concurrently with similar chemotherapy (n = 26) without GnRH-a or were historical controls (n = 20).

MAIN OUTCOME MEASURE(S)

Cyclic ovarian function (COF) versus premature ovarian failure (POF).

RESULT(S)

The ovarian function could be determined in 111 patients. In the GnRH-a/chemotherapy group, 63 out of 65 patients resumed ovulation and regular menses (96.9 %), compared with 63% of the 46 control subjects. Twenty of the 22 patients in the BEACOPP/escalated BEACOPP/GnRH-a cotreatment resumed cyclic ovarian function versus 9 of the 14 in the chemotherapy-only group. All 17 MOPP/ABV/GnRH-a cotreated patients resumed COF versus 11 of the 22 in the chemotherapy-only group. There was no significant effect of the GnRH-a cotreatment regarding COF in the ABVD group. There were no significant differences in the cumulative doses of the various alkylating agents between the two groups.

CONCLUSION(S)

Cotreatment with GnRH-a may reduce ovarian damage significantly in female patients treated for HL and should be considered in addition to assisted reproduction for women in reproductive age receiving gonadotoxic chemotherapy.

Absence of conclusive evidence for the safety and efficacy of gonadotropin-releasing hormone analogue treatment in protecting against chemotherapy-induced gonadal injury

Every year, an increasing number of women with malignant and nonmalignant diseases is successfully treated with cytotoxic chemotherapy and/or radiotherapy. Many of these patients suffer from infertility and gonadal failure as a result of these treatments. At present, these patients may resort to assisted-reproduction techniques to protect their future childbearing potential before the implementation of cytotoxic therapy. While embryo cryopreservation is an established technology, oocyte and ovarian tissue freezing techniques are still investigational. Nevertheless both of these techniques have resulted in live births. Apart from assisted-reproduction techniques, it has been extensively debated whether administration of gonadotropin-releasing hormone (GnRH) analogues in conjunction with chemotherapy can protect ovarian reserve against cytotoxic insult. In this manuscript, we debate the rationale for the effectiveness of GnRH analogue coadministration in preservation of fertility by reviewing the literature, and provide preliminary data to support our views.

Fertility preservation in young women undergoing breast cancer therapy

Breast cancer accounts for one third of all neoplasms seen in reproductive-age women and affects tens of thousands of women each year in that age group. The adjuvant chemotherapy regimens used for the treatment commonly affect fertility and cause premature ovarian failure. There have been recent advances in the field of fertility preservation, which can allow many of these breast cancer survivors to have children in the future. The most established option is embryo cryopreservation; oocyte cryopreservation can be considered in single women. Both of these approaches require approximately 2 weeks of ovarian stimulation beginning with the onset of the patient's menstrual cycle. Thus, it is crucial that these patients are referred to appropriate assisted reproduction centers as soon as they are diagnosed with breast cancer. Recently developed ovarian stimulation protocols using tamoxifen and letrozole can be used to increase the margin of safety in these patients. When and if a breast cancer patient does not have time to undergo ovarian stimulation prior to chemotherapy, ovarian cryopreservation for future autotransplantation can be offered as the last resort. The benefit of ovarian protection by gonadotropin-releasing hormone analogues is unproven and unlikely, and thus this treatment should not be offered as the sole method of fertility preservation.

Müllerian inhibiting substance as a novel biomarker of cisplatin-induced ovarian damage

Müllerian inhibiting substance (MIS) has been investigated as a possible serum biomarker in human aging to estimate the number of female germ cells remaining. Cisplatin is an effective chemotherapeutic agent that is associated with ovarian injury. In this study, we tested the hypothesis that decreasing serum MIS can serve as a biomarker of ovarian damage after cisplatin. Adult female rats were treated with saline, 4.5, or 6.0 mg/kg cisplatin. The serum MIS levels were lower in both cisplatin groups, in a dose-related fashion. The ovarian lysates of both cisplatin groups had less MIS than control. Immunofluorescence analysis showed that the percentage of MIS-positive follicles was lower in the 6.0 mg/kg group. TUNEL assays showed that there was a dose related increase in the number of apoptotic follicles in the cisplatin groups. In summary, a decrease in serum MIS could serve as a biomarker to discriminate the degree of ovarian damage after cisplatin. These data are the first to establish in the rat that ovarian injury due to a chemotherapeutic agent could be monitored with the non-invasive serum biomarker MIS.