T.M. Mooij

Risks of breast, ovarian, and contralateral breast cancer for BRCA1 and BRCA2 mutation carriers

Importance The clinical management of BRCA1 and BRCA2 mutation carriers requires accurate, prospective cancer risk estimates. Objectives To estimate age-specific risks of breast, ovarian, and contralateral breast cancer for mutation carriers and to evaluate risk modification by family cancer history and mutation location. Design, Setting, and Participants Prospective cohort study of 6036 BRCA1 and 3820 BRCA2 female carriers (5046 unaffected and 4810 with breast or ovarian cancer or both at baseline) recruited in 1997-2011 through the International BRCA1/2 Carrier Cohort Study, the Breast Cancer Family Registry and the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer, with ascertainment through family clinics (94%) and population-based studies (6%). The majority were from large national studies in the United Kingdom (EMBRACE), the Netherlands (HEBON), and France (GENEPSO). Follow-up ended December 2013; median follow-up was 5 years. Exposures BRCA1/2 mutations, family cancer history, and mutation location. Main Outcomes and Measures Annual incidences, standardized incidence ratios, and cumulative risks of breast, ovarian, and contralateral breast cancer. Results Among 3886 women (median age, 38 years; interquartile range [IQR], 30-46 years) eligible for the breast cancer analysis, 5066 women (median age, 38 years; IQR, 31-47 years) eligible for the ovarian cancer analysis, and 2213 women (median age, 47 years; IQR, 40-55 years) eligible for the contralateral breast cancer analysis, 426 were diagnosed with breast cancer, 109 with ovarian cancer, and 245 with contralateral breast cancer during follow-up. The cumulative breast cancer risk to age 80 years was 72% (95% CI, 65%-79%) for BRCA1 and 69% (95% CI, 61%-77%) for BRCA2 carriers. Breast cancer incidences increased rapidly in early adulthood until ages 30 to 40 years for BRCA1 and until ages 40 to 50 years for BRCA2 carriers, then remained at a similar, constant incidence (20-30 per 1000 person-years) until age 80 years. The cumulative ovarian cancer risk to age 80 years was 44% (95% CI, 36%-53%) for BRCA1 and 17% (95% CI, 11%-25%) for BRCA2 carriers. For contralateral breast cancer, the cumulative risk 20 years after breast cancer diagnosis was 40% (95% CI, 35%-45%) for BRCA1 and 26% (95% CI, 20%-33%) for BRCA2 carriers (hazard ratio [HR] for comparing BRCA2 vs BRCA1, 0.62; 95% CI, 0.47-0.82; P=.001 for difference). Breast cancer risk increased with increasing number of first- and second-degree relatives diagnosed as having breast cancer for both BRCA1 (HR for ≥2 vs 0 affected relatives, 1.99; 95% CI, 1.41-2.82; P<.001 for trend) and BRCA2 carriers (HR, 1.91; 95% CI, 1.08-3.37; P=.02 for trend). Breast cancer risk was higher if mutations were located outside vs within the regions bounded by positions c.2282-c.4071 in BRCA1 (HR, 1.46; 95% CI, 1.11-1.93; P=.007) and c.2831-c.6401 in BRCA2 (HR, 1.93; 95% CI, 1.36-2.74; P<.001). Conclusions and Relevance These findings provide estimates of cancer risk based on BRCA1 and BRCA2 mutation carrier status using prospective data collection and demonstrate the potential importance of family history and mutation location in risk assessment.

Risk of borderline and invasive ovarian tumours after ovarian stimulation for in vitro fertilization in a large Dutch cohort

BACKGROUND Long-term effects of ovarian stimulation for IVF on the risk of ovarian malignancies are unknown. METHODS We identified a nationwide historic cohort of 19 146 women who received IVF treatment in the Netherlands between 1983 and 1995, and a comparison group of 6006 subfertile women not treated with IVF. In 1997–1999, data on reproductive risk factors were obtained from 65% of women and data on subfertility (treatment) were obtained from the medical records. The incidence of ovarian malignancies (including borderline ovarian tumours) through 2007 was assessed through linkage with disease registries. The risk of ovarian malignancies in the IVF group was compared with risks in the general population and the subfertile comparison group. RESULTS After a median follow-up of 14.7 years, the risk of borderline ovarian tumours was increased in the IVF group compared with the general population [standardized incidence ratio (SIR) = 1.76; 95% confidence interval (CI) = 1.16–2.56]. The overall SIR for invasive ovarian cancer was not significantly elevated, but increased with longer follow-up after first IVF (P = 0.02); the SIR was 3.54 (95% CI = 1.62–6.72) after 15 years. The risks of borderline ovarian tumours and of all ovarian malignancies combined in the IVF group were significantly increased compared with risks in the subfertile comparison group (hazard ratios = 4.23; 95% CI = 1.25–14.33 and 2.14; 95% CI = 1.07–4.25, respectively, adjusted for age, parity and subfertility cause). CONCLUSIONS Ovarian stimulation for IVF may increase the risk of ovarian malignancies, especially borderline ovarian tumours. More large cohort studies are needed to confirm these findings and to examine the effect of IVF treatment characteristics.

Improved overall survival after contralateral risk-reducing mastectomy in BRCA1/2 mutation carriers with a history of unilateral breast cancer: a prospective analysis

Data on survival of BRCA1/2‐associated primary breast cancer (PBC) patients who opt for subsequent contralateral risk‐reducing mastectomy (CRRM) are scarce and inconsistent. We examined the efficacy of CRRM on overall survival in mutation carriers with a history of PBC. From a Dutch multicentre cohort, we selected 583 BRCA‐associated PBC patients, being diagnosed between 1980 and 2011. Over time, 242 patients (42%) underwent CRRM and 341 patients (58%) remained under surveillance. Survival analyses were performed using Cox models, with CRRM as a time‐dependent covariate. The median follow‐up after PBC diagnosis was 11.4 years. In the CRRM group, four patients developed contralateral breast cancer (2%), against 64 patients (19%) in the surveillance group (p < 0.001). The mortality was lower in the CRRM group than in the surveillance group (9.6 and 21.6 per 1000 person‐years of observation, respectively; adjusted hazard ratio 0.49, 95% confidence interval 0.29–0.82). Survival benefit was especially seen in young PBC patients (<40 years), in patients having a PBC with differentiation grade 1/2 and/or no triple‐negative phenotype, and in patients not treated with adjuvant chemotherapy. We conclude that CRRM is associated with improved overall survival in BRCA1/2 mutation carriers with a history of PBC. Further research is warranted to develop a model based on age at diagnosis and tumour and treatment characteristics that can predict survival benefit for specific subgroups of patients, aiming at further personalized counselling and improved decision making.

A reduced size of the ovarian follicle pool is associated with an increased risk of a trisomic pregnancy in IVF-treated women

BACKGROUND The increased risk of a trisomic pregnancy with a womans age arises from an increased rate of meiotic non-disjunction in the oocytes. It has been hypothesized that the increase in meiotic errors is related to the decreasing number of oocytes with age. Our aim was to assess the relation between trisomic pregnancy and three parameters of oocyte quantity. METHODS In a Dutch nationwide database on in vitro fertilization (IVF) treatment from 1983 to 1995, we identified 28 women with a trisomic pregnancy conceived via or within 1 year from IVF treatment. We selected five age-matched controls with a healthy child for each trisomy case. We performed a case-control study to examine whether trisomy cases more often had a history of ovarian surgery and a lower response to ovarian hyperstimulation than controls. Subsequently, cases and controls were followed to compare the incidence of signs of menopause at the end of the study period as self-reported by questionnaire. RESULTS Logistic regression analysis showed an association between trisomic pregnancy and a history of ovarian surgery [odds ratio (OR) 3.3; 95% confidence interval (CI): 1.0-10.5; P = 0.04] and between trisomic pregnancy and retrieval of < or = 4 oocytes during IVF treatment (OR 4.0; 95% CI: 1.4-11.5; P = 0.01). The adjusted OR for signs of menopause associated with trisomic pregnancy was 5.7 (95% CI: 1.1-29.9; P = 0.04). CONCLUSIONS Our results suggest that IVF-treated women with a reduced ovarian follicle pool are at increased risk of a trisomic pregnancy, independent of their age. Our findings support the hypothesis that follicle pool size and not chronological age determines a womans trisomy risk. Since a questionnaire was used, we cannot fully exclude the possibility of selection bias in this study.

Increased risk for ovarian cancer and borderline ovarian tumours in subfertile women with endometriosis

STUDY QUESTION Is ovarian or extra-ovarian endometriosis associated with an increased risk of ovarian cancer and borderline ovarian tumours (BOT)? SUMMARY ANSWER We found a 3- to 8-fold increased risk of ovarian tumours associated with endometriosis: the magnitude of the risk increase depended on the definition of endometriosis. WHAT IS KNOWN ALREADY There is increasing evidence of an association between endometriosis and increased risk of ovarian cancer. However, most reports were based on self-reported diagnosis of endometriosis. STUDY DESIGN, SIZE, DURATION We conducted a nationwide historic cohort study among women with subfertility problems between 1980 and 1995. For this analysis we selected all cohort members with endometriosis, and a comparison group of subfertile women (male factor or idiopathic) without endometriosis (total cohort of 8904 women). Median follow-up time was 15.2 for the entire study population. PARTICIPANTS/MATERIALS, SETTING, METHODS For this analysis we selected all cohort members with (n = 3657) and without (n = 5247) evidence of endometriosis. Seventy-eight per cent of diagnoses of endometriosis were confirmed by pathology report, and 22% was self-reported endometriosis (positive predictive value of 73%). We linked the cohort with the Dutch Pathology Database and the Netherlands Cancer Registry to assess the occurrence of ovarian cancer and BOT between January 1989 and June 2007. MAIN RESULTS AND THE ROLE OF CHANCE We observed a substantially increased risk of all ovarian malignancies combined in women with endometriosis when we based the definition of endometriosis on self-report, medical records information at subfertility treatment and/or the nationwide pathology database (hazard ratio (HR) 8.2; 95% confidence interval (CI) 3.1-21.6). The HR associated with endometriosis was 12.4 (95% CI 2.8-54.2) for ovarian cancer and 5.5 (95% CI 1.5-20.2) for BOT. When we excluded information from the pathology database, HRs were 3.0 (95% CI 1.5-6.1) for all ovarian tumours, 4.3 (95% CI 1.6-11.2) for ovarian cancer and 1.9 (95% CI 0.6-5.8) for BOT. Both ovarian and extra-ovarian endometriosis carried a significantly increased risk for ovarian cancer and BOT. LIMITATIONS, REASONS FOR CAUTION We did not have information on oral contraceptive use and parity for 23.4 and 3.4%, of women in the analytic cohort, respectively. Furthermore, a limitation of our study, and also of other studies, is that the date of diagnosis of endometriosis is usually made long after the onset of the disease. Also, the number of cases in the cohort is small (n = 34), resulting in wide CIs. WIDER IMPLICATIONS OF THE FINDINGS The fact that endometriosis was assessed before diagnosis of ovarian malignancy and the high degree of medical confirmation in our study likely contribute to the validity of our estimate of a 3- to 8-fold increased risk of ovarian tumours associated with endometriosis. The risk of ovarian malignancies associated with endometriosis was much higher in analyses including information on endometriosis from the nationwide pathology database, implying that risk estimates from studies using self-reported information on endometriosis may be too low due to non-differential misclassification bias. STUDY FUNDING/COMPETING INTEREST(S) None. TRIAL REGISTRATION NUMBER None.

Miscarriage risk for IVF pregnancies in poor responders to ovarian hyperstimulation

The increasing miscarriage rate with advancing female age is attributed to a decline in oocyte quality. A poor response to ovarian hyperstimulation is often an expression of a decrease in oocyte quantity. Although oocyte quality and quantity both decrease as a result of ovarian ageing, it is unclear whether these two processes are related to each other. To investigate the relationship between oocyte quantity and quality, we compared miscarriage rates between IVF treated women with a poor and normal response, respectively. Data were studied from a retrospective nationwide cohort of Dutch women undergoing IVF treatment from 1983 to 1995. Women achieving an ongoing pregnancy after their first complete IVF cycle (n=1468) were compared with those experiencing miscarriage (n=357) with respect to their ovarian response. Logistic regression analysis showed a statistically significant association between poor response (fewer than four retrieved oocytes) and miscarriage (P=0.001). Due to interaction, this association became stronger with increasing female age. Among women < 36 years, miscarriage rates between poor and normal responders did not differ, whereas among women 36 years poor responders had a statistically significant increased miscarriage rate compared with normal responders (P=0.001). These results support the hypothesis of a relationship between quantitative ovarian reserve and oocyte quality.

Melanoma risk after ovarian stimulation for in vitro fertilization

STUDY QUESTION Do women treated with ovarian stimulation for IVF have an increased risk of melanoma? SUMMARY ANSWER Ovarian stimulation for IVF does not increase risk of melanoma, even after a prolonged follow-up. WHAT IS KNOWN ALREADY Although exposure to ultraviolet radiation is the major risk factor for melanoma, associations between female sex steroids and melanoma risk have also been suggested. The results of available studies on fertility drugs and melanoma risk are inconclusive since most studies had several methodological limitations such as short follow-up, a small number of cases and no subfertile comparison group. STUDY DESIGN, SIZE, DURATION In 1996, a nationwide historic cohort study (the OMEGA-cohort) was established to examine the risk of cancer after ovarian stimulation for IVF. After a median follow-up of 17 years, cancer incidence was ascertained through linkage with the Netherlands Cancer Registry. Melanoma risk in the cohort was compared with that in the general population and between the IVF group and non-IVF group using multivariable Cox regression analyses. PARTICIPANTS/MATERIALS, SETTING, METHODS The cohort comprises 19 158 women who received IVF between 1983 and 1995 and a comparison group of 5950 women who underwent subfertility treatments other than IVF. Detailed IVF-treatment data were obtained from the medical records and complete information on parity and age at first birth was obtained through linkage with the Dutch Municipal Personal Records Database. MAIN RESULTS AND THE ROLE OF CHANCE In total, 93 melanoma cases were observed. The risk of melanoma was not elevated among IVF-treated women, neither when compared with the general population (standardized incidence ratio = 0.89; 95% confidence interval (CI): 0.69-1.12), nor when compared with the non-IVF group (adjusted hazard ratio (HR) = 1.27; 95% CI: 0.75-2.15). A higher number of IVF cycles was associated with apparent but statistically non-significant risk increases (5-6 cycles HR = 1.92; ≥7 cycles HR = 1.79). However, no significant trend emerged. In women with more follicle stimulating hormone/human menopausal gonadotrophin ampoules comparable non-significant risk increases were found. A longer follow-up did not increase melanoma risk. Nulliparous women did not have a significantly higher melanoma risk than parous women (HR = 1.22; 95% CI: 0.81-1.84). However, women who were 30 years of age or older at first birth had a significantly higher melanoma risk than women who were younger than 30 years at first birth (age: 30-34 years HR = 4.57; 95% CI: 2.07-10.08, >34 years HR = 2.98; 95% CI: 1.23-7.21). LIMITATIONS, REASONS FOR CAUTION Despite our large cohort, the number of melanoma cases was rather small, especially in our comparison group, which hampered subgroup analyses. WIDER IMPLICATIONS OF THE FINDINGS Our results are reassuring for women who underwent IVF or are contemplating to start IVF. Since our cohort study is one of the largest published so far, with long-term follow-up, a subfertile comparison group, and detailed IVF-treatment data, our results add important information to the available evidence. STUDY FUNDING/COMPETING INTEREST This study was supported by grants from the Dutch Cancer Society (NKI 2006-3631), the Health Research and Development Counsel (28-2540) and the Dutch Ministry of Health.

Increased breast cancer risk in in vitro fertilisation treated women with a multiple pregnancy: A new hypothesis based on historical in vitro fertilisation treatment data

BACKGROUND Breast cancer risk is temporarily increased after a full-term pregnancy and declines thereafter, possibly due to increased levels of gonadal and placental hormones during pregnancy. Inconsistent results, however, have been reported after twin pregnancies with higher hormone levels. Among women treated with in vitro fertilisation (IVF), for whom the number of embryos available for implantation is known, we recently observed that a multiple birth after implantation of all transferred embryos is associated with higher levels of vascular endothelial growth factor (VEGF). As VEGF is involved in breast cancer progression, we studied the effects of embryo implantation and a multiple birth on breast cancer risk in a nationwide Dutch cohort of IVF-treated women. METHODS We performed a cohort analysis among 12,589 women who had been treated with IVF between 1983 and 1995 and completed a risk factor questionnaire between 1997 and 1999. Data on IVF treatment were obtained from medical records. Breast cancer cases were ascertained through linkage with the population-based Netherlands Cancer Registry. Breast cancer risks associated with singleton and multiple births were estimated with Cox regression. FINDINGS There were 1688 women (13.4%) with multiples, 6027 (47.9%) with singletons and 4874 (38.7%) nulliparous women. Breast cancer occurred in 317 women of whom 57 had multiples. Breast cancer risk was 1.44 times higher in mothers of multiples than in mothers of singletons (95% confidence interval (CI) 1.06-1.97). Risk was highest in women who gave birth to multiples from all embryos transferred (adjusted hazard ratio (HR) 1.86, 95% CI 1.01-3.43), and lower for those with multiples after incomplete embryo implantation (adjusted HR 1.31, 95% CI 0.76-2.25). INTERPRETATION A womans potential to implant all transferred embryos may be associated with breast cancer risk. Further research is needed to confirm our results and to identify the underlying biological mechanisms.

Do BRCA1/2 mutation carriers have an earlier onset of natural menopause?

Objective:It has been hypothesized that BRCA1/2 mutation carriers have an earlier age at natural menopause (ANM), although to date findings are inconclusive. This study assessed the influence of BRCA mutation status on ANM, and aimed to explore the reasons of inconsistency in the literature. Methods:Cross-sectional assessment from an ongoing nationwide cohort study among members of BRCA1/2 mutated families. Information was obtained by a standardized questionnaire. Kaplan-Meier curves were constructed, and Cox regression was used to assess the association between BRCA1/2 mutation status and ANM. Adjustments were made for birth cohort, family, smoking, use of hormonal contraceptives, and parity. Results:A total of 1,208 BRCA1/2 mutation carriers and 2,211 proven noncarriers were included. Overall, no association was found between BRCA1/2 mutation status and ANM (adjusted hazard ratio [HR] = 1.06 [95% CI, 0.87-1.30]). We examined if the null finding was due to informative censoring by uptake of risk-reducing salpingo-oophorectomy. Indeed, within the oldest birth cohort, in which the percentage of surgical menopause events was lowest and comparable between carriers and noncarriers, the HR for earlier natural menopause in carriers was 1.45 (95% CI, 1.09-1.94). The second oldest birth cohort, however, demonstrated a decreased HR (0.67 [95% CI, 0.46-0.98]), and thus no trend over birth cohorts was found. Conclusions:Various types of selection bias hamper the comparison of ANM between BRCA1/2 mutation carriers and noncarriers, genetically tested in the clinic.

Oral contraceptive use and breast cancer risk: retrospective and prospective analyses from a BRCA1 and BRCA2 mutation carrier cohort study

Abstract Background For BRCA1 and BRCA2 mutation carriers, the association between oral contraceptive preparation (OCP) use and breast cancer (BC) risk is still unclear. Methods Breast camcer risk associations were estimated from OCP data on 6030 BRCA1 and 3809 BRCA2 mutation carriers using age-dependent Cox regression, stratified by study and birth cohort. Prospective, left-truncated retrospective and full-cohort retrospective analyses were performed. Results For BRCA1 mutation carriers, OCP use was not associated with BC risk in prospective analyses (hazard ratio [HR] = 1.08, 95% confidence interval [CI] = 0.75 to 1.56), but in the left-truncated and full-cohort retrospective analyses, risks were increased by 26% (95% CI = 6% to 51%) and 39% (95% CI = 23% to 58%), respectively. For BRCA2 mutation carriers, OCP use was associated with BC risk in prospective analyses (HR = 1.75, 95% CI = 1.03 to 2.97), but retrospective analyses were inconsistent (left-truncated: HR = 1.06, 95% CI = 0.85 to 1.33; full cohort: HR = 1.52, 95% CI = 1.28 to 1.81). There was evidence of increasing risk with duration of use, especially before the first full-term pregnancy (BRCA1: both retrospective analyses, P < .001 and P = .001, respectively; BRCA2: full retrospective analysis, P = .002). Conclusions Prospective analyses did not show that past use of OCP is associated with an increased BC risk for BRCA1 mutation carriers in young middle-aged women (40–50 years). For BRCA2 mutation carriers, a causal association is also not likely at those ages. Findings between retrospective and prospective analyses were inconsistent and could be due to survival bias or a true association for younger women who were underrepresented in the prospective cohort. Given the uncertain safety of long-term OCP use for BRCA1/2 mutation carriers, indications other than contraception should be avoided and nonhormonal contraceptive methods should be discussed.