Inter-individual variation in ovarian reserve after gonadotoxic treatment in female childhood cancer survivors - a genome-wide association study: results from PanCareLIFE.

OBJECTIVE: We aimed to discover new variants associated with low ovarian reserve after gonadotoxic treatment among adult female childhood cancer survivors using a genome-wide association study approach. DESIGN: Genome-wide association study. SUBJECTS: A discovery cohort of adult female childhood cancer survivors, from the pan-European PanCareLIFE cohort (n=743; median age: 25.8 years), excluding those who received bilateral ovarian irradiation, bilateral oophorectomy, central nerve system or total body irradiation, or stem cell transplantation. Replication was attempted in the USA-based St. Jude Lifetime Cohort (n=391; median age: 31.3 years). EXPOSURE: Female childhood cancer survivors are at risk of therapy-related gonadal impairment. Alkylating agents are well-established risk factors, and the inter-individual variability in gonadotoxicity may be explained by genetic polymorphisms. Data were collected in real-life conditions and cyclophosphamide equivalent dose was used to quantify alkylation agent exposure. INTERVENTION: No intervention was performed. MAIN OUTCOME MEASURE: Anti-Müllerian hormone (AMH) levels served as a proxy for ovarian function and findings were combined in a meta-analysis. RESULTS: Three genome-wide significant (<5.0x10-8) and 16 genome-wide suggestive (<5.0x10-6) loci were associated with log-transformed AMH levels, adjusted for cyclophosphamide equivalent dose of alkylating agents, age at diagnosis, and age at study in the PanCareLIFE cohort. Based on effect allele frequency (EAF) (>0.01 if not genome-wide significant), p-value (<5.0×10-6), and biological relevance, 15 SNPs were selected for replication. None of the SNPs were statistically significantly associated with AMH levels. A meta-analysis indicated that rs78861946 was associated at borderline genome-wide statistical significance (Reference/effect allele: C/T; EAF: 0.04, Beta (SE): -0.484 (0.091), p-value= 9.39×10-8). CONCLUSION: This study found no genetic variants associated with a lower ovarian reserve after gonadotoxic treatment, as the findings of this GWAS were not statistically significant replicated in the replication cohort. Suggestive evidence for potential importance of one variant is briefly discussed, but the lack of statistical significance calls for larger cohort sizes. As the population of childhood cancer survivors is increasing, large-scale and systematic research is needed to identify genetic variants that could aid predictive risk models of gonadotoxicity and as well as fertility preservation options for childhood cancer survivors.

Endometrial thickness assessed by transvaginal ultrasound in transmasculine people taking testosterone compared with cisgender women.

RESEARCH QUESTION: What is the endometrial thickness of endometrium exposed to testosterone in transmasculine people compared with unexposed endometrium in cisgender women as determined by transvaginal ultrasound (TVU)? DESIGN: Single centre, cross-sectional cohort study conducted the Centre of Expertise on Gender Dysphoria in Amsterdam. Between 2013 and 2015, transmasculine people scheduled for gender affirming surgery (GAS) were included in this study after they provided informed consent. They were undergoing gender affirming hormone therapy (testosterone) for at least 1 year. Endometrial thickness (mm) was measured by TVU in transmasculine people, immediately before their GAS while under general anaesthesia. Cisgender control women from the general population underwent the exact same TVU measurements in an outpatient clinical setting on cycle days 2-5. RESULT: Fifty-one transmasculine people and 77 controls were included. The mean duration of testosterone use was 30.2 months (SD 8.8). Endometrial thickness was significantly lower in transmasculine people compared with cisgender women: median 3.9 mm (interquartile range [IQR] 2.8-5.1) and 4.9 mm (IQR 4.0-6.3), respectively (P < 0.001), after correcting for confounding factor (current gonadotrophin releasing hormone agonist use). CONCLUSIONS: Endometrial thickness in transmasculine people exposed to testosterone is significantly lower compared with cisgender women without testosterone exposure. These results suggest an absence of endometrial proliferation by exogenous testosterone.

Effect of Genetic Variation in CYP450 on Gonadal Impairment in a European Cohort of Female Childhood Cancer Survivors, Based on a Candidate Gene Approach: Results from the PanCareLIFE Study.

BACKGROUND: Female childhood cancer survivors (CCSs) carry a risk of therapy-related gonadal dysfunction. Alkylating agents (AA) are well-established risk factors, yet inter-individual variability in ovarian function is observed. Polymorphisms in CYP450 enzymes may explain this variability in AA-induced ovarian damage. We aimed to evaluate associations between previously identified genetic polymorphisms in CYP450 enzymes and AA-related ovarian function among adult CCSs. METHODS: Anti-Müllerian hormone (AMH) levels served as a proxy for ovarian function in a discovery cohort of adult female CCSs, from the pan-European PanCareLIFE cohort (n = 743; age (years): median 25.8, interquartile range (IQR) 22.1-30.6). Using two additive genetic models in linear and logistic regression, nine genetic variants in three CYP450 enzymes were analyzed in relation to cyclophosphamide equivalent dose (CED) score and their impact on AMH levels. The main model evaluated the effect of the variant on AMH and the interaction model evaluated the modifying effect of the variant on the impact of CED score on log-transformed AMH levels. Results were validated, and meta-analysis performed, using the USA-based St. Jude Lifetime Cohort (n = 391; age (years): median 31.3, IQR 26.6-37.4). RESULTS: CYP3A4*3 was significantly associated with AMH levels in the discovery and replication cohort. Meta-analysis revealed a significant main deleterious effect (Beta (95% CI): -0.706 (-1.11--0.298), p-value = 7 × 10-4) of CYP3A4*3 (rs4986910) on log-transformed AMH levels. CYP2B6*2 (rs8192709) showed a significant protective interaction effect (Beta (95% CI): 0.527 (0.126-0.928), p-value = 0.01) on log-transformed AMH levels in CCSs receiving more than 8000 mg/m2 CED. CONCLUSIONS: Female CCSs CYP3A4*3 carriers had significantly lower AMH levels, and CYP2B6*2 may have a protective effect on AMH levels. Identification of risk-contributing variants may improve individualized counselling regarding the treatment-related risk of infertility and fertility preservation options.

Possible modification of BRSK1 on the risk of alkylating chemotherapy-related reduced ovarian function.

STUDY QUESTION: Do genetic variations in the DNA damage response pathway modify the adverse effect of alkylating agents on ovarian function in female childhood cancer survivors (CCS)? SUMMARY ANSWER: Female CCS carrying a common BR serine/threonine kinase 1 (BRSK1) gene variant appear to be at 2.5-fold increased odds of reduced ovarian function after treatment with high doses of alkylating chemotherapy. WHAT IS KNOWN ALREADY: Female CCS show large inter-individual variability in the impact of DNA-damaging alkylating chemotherapy, given as treatment of childhood cancer, on adult ovarian function. Genetic variants in DNA repair genes affecting ovarian function might explain this variability. STUDY DESIGN, SIZE, DURATION: CCS for the discovery cohort were identified from the Dutch Childhood Oncology Group (DCOG) LATER VEVO-study, a multi-centre retrospective cohort study evaluating fertility, ovarian reserve and risk of premature menopause among adult female 5-year survivors of childhood cancer. Female 5-year CCS, diagnosed with cancer and treated with chemotherapy before the age of 25 years, and aged 18 years or older at time of study were enrolled in the current study. Results from the discovery Dutch DCOG-LATER VEVO cohort (n = 285) were validated in the pan-European PanCareLIFE (n = 465) and the USA-based St. Jude Lifetime Cohort (n = 391). PARTICIPANTS/MATERIALS, SETTING, METHODS: To evaluate ovarian function, anti-Müllerian hormone (AMH) levels were assessed in both the discovery cohort and the replication cohorts. Using additive genetic models in linear and logistic regression, five genetic variants involved in DNA damage response were analysed in relation to cyclophosphamide equivalent dose (CED) score and their impact on ovarian function. Results were then examined using fixed-effect meta-analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Meta-analysis across the three independent cohorts showed a significant interaction effect (P = 3.0 × 10-4) between rs11668344 of BRSK1 (allele frequency = 0.34) among CCS treated with high-dose alkylating agents (CED score ≥8000 mg/m2), resulting in a 2.5-fold increased odds of a reduced ovarian function (lowest AMH tertile) for CCS carrying one G allele compared to CCS without this allele (odds ratio genotype AA: 2.01 vs AG: 5.00). LIMITATIONS, REASONS FOR CAUTION: While low AMH levels can also identify poor responders in assisted reproductive technology, it needs to be emphasized that AMH remains a surrogate marker of ovarian function. WIDER IMPLICATIONS OF THE FINDINGS: Further research, validating our findings and identifying additional risk-contributing genetic variants, may enable individualized counselling regarding treatment-related risks and necessity of fertility preservation procedures in girls with cancer. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the PanCareLIFE project that has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 602030. In addition, the DCOG-LATER VEVO study was funded by the Dutch Cancer Society (Grant no. VU 2006-3622) and by the Children Cancer Free Foundation (Project no. 20) and the St Jude Lifetime cohort study by NCI U01 CA195547. The authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Female reproductive function after treatment of childhood acute lymphoblastic leukemia.

BACKGROUND: The aim was to evaluate self-reported reproductive characteristics and markers of ovarian function in a nationwide cohort of female survivors of childhood acute lymphoblastic leukemia (ALL), because prior investigations have produced conflicting data. PROCEDURE: Self-reported reproductive characteristics were assessed by questionnaire among 357 adult 5-year survivors, treated between 1964 and 2002, and 836 controls. Ovarian function was assessed by serum levels of anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), and inhibin B and by antral follicle count (AFC). Differences between controls and (subgroups of) survivors (total group, chemotherapy [CT]-only group, CT and radiotherapy [RT] group) were analyzed. RESULTS: Survivors treated with CT only do not differ from controls regarding timing of menarche, virginity status, desire for children, or pregnancy rates. Compared to controls, the CT+RT group was at significantly increased risk of a younger age at menarche (P < .01), virginity, an absent desire for children, and lower pregnancy rates (odds ratio [OR] [95% CI]: 0.3 [CI 0.1-0.6], 0.5 [0.3-0.9], and 0.4 [0.2-0.9], respectively). Survivors in the CT-only group were significantly younger at the birth of their first child. Pregnancy outcomes were not significantly different between any (sub)groups. Survivors treated with total body irradiation (TBI) or hematopoietic stem cell transplantation (HSCT) are at increased risk of abnormal markers of ovarian function. CONCLUSION: Reproductive function of ALL survivors treated with CT only does not differ from controls. However, survivors additionally treated with RT seem to be at an increased risk of certain adverse reproductive outcomes. Providing personalized counseling about (future) reproductive health risks in this group is imperative.

Uterine function, pregnancy complications, and pregnancy outcomes among female childhood cancer survivors.

OBJECTIVE: To evaluate whether abdominal-pelvic radiotherapy for childhood cancer impairs uterine function and increases the risk of pregnancy complications and adverse pregnancy outcomes. DESIGN: Nested cohort study. SETTING: Not applicable. PATIENT(S): Childhood cancer survivors previously exposed to abdominal-pelvic radiotherapy (RT-exposed CCSs) as part of their treatment for childhood cancer. INTERVENTION(S): Radiotherapy-exposed CCSs (n = 55) were age- and parity-matched to nonirradiated CCSs (non-RT-exposed CCSs; n = 110) and general population controls (n = 110). MAIN OUTCOME MEASURES: Uterine volume, pregnancy complications, and pregnancy outcomes. RESULT(S): Among nulligravidous participants, median (interquartile range) uterine volume was 41.4 (18.6-52.8) mL for RT-exposed CCSs, 48.1 (35.7-61.8) mL for non-RT-exposed CCSs, and 61.3 (49.1-75.5) mL for general population controls. Radiotherapy-exposed CCSs were at increased risk of a reduced uterine volume (<44.3 mL) compared with population controls (odds ratio [OR] 5.31 [95% confidence interval 1.98-14.23]). Surprisingly, the same was true for non-RT-exposed CCSs (OR 2.61 [1.16-5.91]). Among gravidous participants, RT-exposed CCSs had increased risks of pregnancy complications, preterm delivery, and a low birth weight infant compared with population controls (OR 12.70 [2.55-63.40], OR 9.74 [1.49-63.60], and OR 15.66 [1.43-171.35], respectively). Compared with non-RT-exposed CCSs, RT-exposed CCSs were at increased risk of delivering a low birth weight infant (OR 6.86 [1.08-43.75]). CONCLUSION(S): Uterine exposure to radiotherapy during childhood reduces adult uterine volume and leads to an increased risk of pregnancy complications and adverse pregnancy outcomes. Preconceptional counseling and appropriate obstetric monitoring is warranted.

Effects of long-term exogenous testosterone administration on ovarian morphology, determined by transvaginal (3D) ultrasound in female-to-male transsexuals.

STUDY QUESTION: Does long-term exogenous testosterone administration result in polycystic ovarian morphology (PCOM), determined by (3D) transvaginal ultrasound (TVU) in female-to-male transsexuals (FtMs). SUMMARY ANSWER: Long-term exogenous testosterone administration in FtMs does not result in PCOM determined by (3D) TVU. WHAT IS KNOWN ALREADY: The role of androgens in the pathophysiology of polycystic ovary syndrome (PCOS) is still unclear. From animal studies, intra-ovarian androgens have been suggested to disturb folliculogenesis, through a pro-atretic effect on growing follicles. It remains debatable whether exogenous androgens induce PCOM in humans. In the past histomorphologic studies indicated that androgen administration in FtMs could cause PCO-like changes. However, ultrasound morphology is an established criterion for PCOS, TVU data of ovaries after prolonged androgen exposure are lacking. STUDY DESIGN, SIZE, DURATION: Prospective, observational, case-control study, in an academic setting, performed in 2014-2015, including 56 FtMs and 80 controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study population consisted of adult FtMs treated with long-term testosterone, as part of their cross-sex hormone treatment, and scheduled for sex-reassignment surgery (bilateral salpingo-oophorectomy). Prior to the operation, under anaesthetics TVU measurements (3D transvaginal probe 3-9 MHz; HD11, Philips Ultrasound, Inc.) of the ovaries were performed. The control group consisted of females from a general population who underwent the same TVU and analysis. Antral follicle count (AFC) (3D) and ovarian volume (3D) were calculated using specialized software. PCOM was defined as AFC of 12 or more follicles (2-10 mm) in at least one ovary. MAIN RESULTS AND THE ROLE OF CHANCE: Prevalence rates of PCOM were not significantly different in the FtMs compared to controls, determined by (3D) TVU: 32.1% (17/53) versus 30.7% (23/75), P = 0.87. LIMITATIONS, REASONS FOR CAUTION: Testosterone levels in FtMs are supraphysiological, and may not be comparable to the testosterone levels in women with PCOS. However, we applied a unique and ethically acceptable opportunity of exploring the effects of androgens on human ovaries. WIDER IMPLICATIONS OF THE FINDINGS: This first explorative study shows that long-term exogenous testosterone administration in adult women does not seem to induce PCOM determined by TVU. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: The trial was registered at the Dutch Trial Register (www.trialregister.nl), registration number NTR4784.

Chemotherapy-related late adverse effects on ovarian function in female survivors of childhood and young adult cancer: A systematic review.

BACKGROUND: Anti-cancer treatment may reduce the fertile life span and induce premature menopause. This review aims to provide an overview of the available literature on effects of chemotherapy only on the incidence of ovarian dysfunction and to evaluate the relationship between dose of chemotherapy, age at time of treatment, and time since treatment in female survivors of childhood and young adult cancer. METHODS: A comprehensive search of electronic databases was performed (search date December 2015). RESULTS: 45 studies were included, describing, in total, 5607 female survivors. Median age at menopause was earlier in cancer survivors than in the general population. The prevalence of amenorrhoea varied from 0% to 83%. Those exposed to MVPP protocols were at highest risk for amenorrhoea (39-79%), as were breast cancer survivors receiving cyclophosphamide-containing regimens, in whom the prevalence of amenorrhoea was 40-80%. The most important risk factors for ovarian dysfunction were: (1) alkylating agents, specifically procarbazine and busulfan, (2) older age at treatment. CONCLUSION: Breast cancer survivors, those treated with procarbazine or other alkylating agents and those with a higher age at diagnosis are at highest risk of diminished ovarian function. However, all studies included in this review showed methodological limitations. It is imperative that nation-wide registries guarantee long term follow-up during the adult life of cancer survivors.

A nationwide study on reproductive function, ovarian reserve, and risk of premature menopause in female survivors of childhood cancer: design and methodological challenges.

BACKGROUND: Advances in childhood cancer treatment over the past decades have significantly improved survival, resulting in a rapidly growing group of survivors. However, both chemo- and radiotherapy may adversely affect reproductive function. This paper describes the design and encountered methodological challenges of a nationwide study in the Netherlands investigating the effects of treatment on reproductive function, ovarian reserve, premature menopause and pregnancy outcomes in female childhood cancer survivors (CCS), the DCOG LATER-VEVO study. METHODS: The study is a retrospective cohort study consisting of two parts: a questionnaire assessing medical, menstrual, and obstetric history, and a clinical assessment evaluating ovarian and uterine function by hormonal analyses and transvaginal ultrasound measurements. The eligible study population consists of adult female 5-year survivors of childhood cancer treated in the Netherlands, whereas the control group consists of age-matched sisters of the participating CCS. To date, study invitations have been sent to 1611 CCS and 429 sister controls, of which 1215 (75%) and 333 (78%) have responded so far. Of these responders, the majority consented to participate in both parts of the study (53% vs. 65% for CCS and sister controls respectively). Several challenges were encountered involving the study population: dealing with bias due to the differences in characteristics of several types of (non-) participants and finding an adequately sized and well-matched control group. Moreover, the challenges related to the data collection process included: differences in response rates between web-based and paper-based questionnaires, validity of self-reported outcomes, interpretation of clinical measurements of women using hormonal contraceptives, and inter- and intra-observer variation of the ultrasound measurements. DISCUSSION: The DCOG LATER-VEVO study will provide valuable information about the reproductive potential of paediatric cancer patients as well as long-term survivors of childhood cancer. Other investigators planning to conduct large cohort studies on late effects may encounter similar challenges as those encountered during this study. The solutions to these challenges described in this paper may be useful to these investigators. TRIAL REGISTRATION: NTR2922; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2922

Intra-cycle fluctuations of anti-Müllerian hormone in normal women with a regular cycle: a re-analysis.

Anti-Müllerian hormone (AMH) has emerged as an important marker of ovarian reserve. Its variation throughout the cycle, however, may still be a matter of debate. The objective of this study was to re-evaluate the intra-cycle fluctuations of AMH in individuals in a prospective clinical study with focus on the age-related effects on these fluctuations. Frequent blood samples were obtained from the mid-luteal phase of the first cycle to the mid-luteal phase of the second cycle in 44 healthy, regularly menstruating Caucasian women. Main outcome measures were individual fluctuations of AMH concentrations during the natural menstrual cycle. AMH concentrations exhibited large fluctuations throughout the cycle and did not follow a defined pattern. Female age was negatively correlated with mean AMH concentrations. The absolute intra-individual variation was also negatively associated with age, whereas the relative intra-individual variation was positively associated with age. Although the fluctuation in relative intra-individual variation was higher in the older group, the absolute variation is very low and these fluctuations might therefore be of limited clinical relevance in this age group. These data show that in younger women caution should be exerted with the interpretation of a single randomly taken AMH measurement as a representative of ovarian reserve.

Malignant melanoma as second malignant neoplasm in long-term childhood cancer survivors: a systematic review.

This systematic review provides information on malignant melanoma as second malignant neoplasm (SMN) after childhood cancer and evaluates its risk factors. Study reports describing incidences of SMN and malignant melanoma as SMN in a population of childhood cancer survivors (CCS) were included. Of 151,575 CCS, 4,010 (2.6%) children developed an SMN, 212 of which were melanoma (5.3% or 0.14% of all CCS). The following risk factors for malignant melanoma as SMN were identified: radiotherapy, or the combination alkylating agents and anti-mitotic drugs. Melanomas are most frequently observed after Hodgkin disease, hereditary retinoblastoma, soft tissue sarcoma, and gonadal tumors.

Using web-based and paper-based questionnaires for collecting data on fertility issues among female childhood cancer survivors: differences in response characteristics.

BACKGROUND: Web-based questionnaires have become increasingly popular in health research. However, reported response rates vary and response bias may be introduced. OBJECTIVE: The aim of this study was to evaluate whether sending a mixed invitation (paper-based together with Web-based questionnaire) rather than a Web-only invitation (Web-based questionnaire only) results in higher response and participation rates for female childhood cancer survivors filling out a questionnaire on fertility issues. In addition, differences in type of response and characteristics of the responders and nonresponders were investigated. Moreover, factors influencing preferences for either the Web- or paper-based version of the questionnaire were examined. METHODS: This study is part of a nationwide study on reproductive function, ovarian reserve, and risk of premature menopause in female childhood cancer survivors. The Web-based version of the questionnaire was available for participants through the Internet by means of a personalized user name and password. Participants were randomly selected to receive either a mixed invitation (paper-based questionnaire together with log-in details for Web-based questionnaire, n = 137) or a Web-only invitation (log-in details only, n = 140). Furthermore, the latter group could request a paper-based version of the questionnaire by filling out a form. RESULTS: Overall response rates were comparable in both randomization groups (83% mixed invitation group vs 89% in Web-only invitation group, P = .20). In addition, participation rates appeared not to differ (66% or 90/137, mixed invitation group vs 59% or 83/140, Web-only invitation group, P =.27). However, in the mixed invitation group, significantly more respondents filled out the paper-based questionnaire compared with the Web-only invitation group (83% or 75/90 and 65% or 54/83, respectively, P = .01). The 44 women who filled out the Web-based version of the questionnaire had a higher educational level than the 129 women who filled out the paper-based version (P = .01). Furthermore, the probability of filling out the Web-based questionnaire appeared to be greater for women who were allocated to the Web-only invitation group (OR = 2.85, 95% CI 1.31-6.21), were older (OR = 1.08, 95% CI 1.02-1.15), had a higher educational level (OR high vs low = 0.06, 95% CI 0.01-0.52), or were students (OR employed vs student = 3.25, 95% CI 1.00-10.56). CONCLUSIONS: Although overall response as well as participation rates to both types of invitations were similar, adding a paper version of a questionnaire to a Web-only invitation resulted in more respondents filling out the paper-based version. In addition, women who were older, had a higher level of education, or were students, were more likely to have filled out the Web-based version of the questionnaire. Given the many advantages of Web-based over paper-based questionnaires, researchers should strongly consider using Web-based questionnaires, although possible response bias when using these types of questionnaires should be taken into account. TRIAL REGISTRATION: Nederlands Trial Register NTR2922; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2922 (Archived by WebCite at http://www.webcitation.org/5zRRdMrDv).

Phenotypic and pharmacogenetic aspects of ovulation induction in WHO II anovulatory women.

Because of an enormous increase in pharmacogenetic and -genomic knowledge, an era of predicting drug response on the basis of one's genome is drawing close to reality. Anovulation is the most common cause of infertility, and outcomes of treatment are often unpredictable. This review aims to summarise in what way genetic variability might modify effects of drug-metabolising enzymes, transporters and receptors, thereby altering response to drugs used in ovulation induction.