Fertility treatments and breast cancer risk in Jewish Israeli BRCA mutation carriers

Oral Contraceptive Use and Breast Cancer Risk for BRCA1 and BRCA2 Mutation Carriers: Systematic Review and Meta-Analysis of Case–Control Studies

Oral contraceptive use is one of the major modifiable risk factors for breast cancer. To investigate the effect of oral contraceptive taking on breast cancer risk by BRCA 1 and BRCA 2 mutation status, we conducted a systematic review and meta-analysis of case-controlled studies. Therefore, English language articles were retrieved by searching MEDLINE (PubMed), EMBASE and the Cochrane Library up to August 2021. Data were pooled from none case–control studies, comprising a total of 33,162 subjects, including 23,453 who had never used oral contraceptives. Overall meta-analysis indicated a statistically insignificant risk reduction: OR = 0.86, 95% CI: 0.70 to 1.06, p = 0.1594. However, increased breast cancer risk was associated with age at first use of OCs ≥20 years: OR = 1.21, 95% CI:1.07 to 1.36, p = 0.002. Multivariable meta-regression with covariates of age of first OC use (β = 0.21, 95% CI: −0.25 to 0.67, p = 0.3767), duration of OC use (β = −0.08, 95% CI; −0.51 to 0.34, p = 0.7093), and time since last OC use (β = 0.32, 95% CI: −0.22 to 0.85, p = 0.2461) did not have a significant effect on the breast cancer risk. This meta-analysis suggests a diverse effect of oral contraceptive use against breast cancer in BRCA carrier mutation. The association between OC use and breast and ovarian cancers needs more investigation.

Controversies and Open Questions in Management of Cancer-Free Carriers of Germline Pathogenic Variants in BRCA1/BRCA2

Females harboring germline BRCA1/BRCA2 (BRCA) P/LPV are offered a tight surveillance scheme from the age of 25−30 years, aimed at early detection of specific cancer types, in addition to risk-reducing strategies. Multiple national and international surveillance guidelines have been published and updated over the last two decades from geographically diverse countries. We searched for guidelines published between 1 January 2015 and 1 May 2022. Differences between guidelines on issues such as primary prevention, mammography screening in young (<30 years) carriers, MRI screening in carriers above age 65 years, breast imaging (if any) after risk-reducing bilateral mastectomy, during pregnancy, and breastfeeding, and hormone-replacement therapy, are just a few notable examples. Beyond formal guidelines, BRCA carriers’ concerns also focus on the timing of risk-reducing surgeries, fertility preservation, management of menopausal symptoms in cancer survivors, and pancreatic cancer surveillance, issues that, for some, there are no data to support evidence-based recommendations. This review discusses these unsettled issues, emphasizing the importance of future studies to enable global guideline harmonization for optimal surveillance strategies. Moreover, it raises the unmet need for personalized risk stratification and surveillance in BRCA P/LPV carriers.

Carcinogenic Potential Of Ovulation Stimulation In BRCA1/2 Gene Mutation Carriers In Assisted Reproductive Technology Programs

Mutations of the BRCA1/2 genes constitute a fundamental and independent risk factor in the genesis of both breast cancer and ovarian cancer. The specifics of the infertility treatment effect on the risk of developing cancer in carriers of mutations in the BRCA1/2 genes remain unclear and require a comprehensive investigation. In this review, we analyzed published sources on the possible relationship between the infertility treatment and the risk of ovarian and breast cancer in BRCA1/2 mutation carriers.

Ovarian stimulation for fertility treatments and risk of breast cancer: a matched cohort study

STUDY QUESTION

Is there a difference in the breast cancer risk among women who underwent ART treatments compared to those who underwent medically assisted reproduction (MAR) infertility treatments or women of reproductive age in the general population?

SUMMARY ANSWER

The risk of breast cancer among women treated by ART was similar to the risk among women treated by MAR and women who did not undergo fertility treatments.

WHAT IS KNOWN ALREADY

Studies investigating breast cancer risk in women who have undergone fertility treatments have provided conflicting results.

STUDY DESIGN, SIZE, DURATION

A retrospective, population-based cohort study included women who underwent ART or MAR treatments and women who did not undergo fertility treatments from 1994 to 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women who underwent ART were matched one to one with women who underwent MAR treatments and one to one with woman from the general population of reproductive age, by year of birth and year of first delivery or nulliparity status. MAR women were also matched to ART women by treatment initiation calendar year. All included women were members of Maccabi Healthcare Services. Data regarding demographics, fertility treatments, BRCA mutation and possible confounders were obtained from the computerized database of electronic health records. The incidence of breast cancer after fertility treatments was compared to the matched controls.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 8 25 721 women of reproductive age, 32 366 women who underwent ART were matched with patients treated by MAR (n = 32 366) and 32 366 women of reproductive age. A total of 984 women (1.0%) were diagnosed with breast cancer (mean follow-up period, 9.1 ± 6.3 years; interquartile range [IQR], 3.8-13.7 years). The incidence rates of breast cancer per 10 000 person-years were 11.9 (95% CI, 10.7-13.3), 10.7 (95% CI, 9.6-11.9) and 10.7 (95% CI, 9.6-12.0) in the ART group, MAR group and general population, respectively. The crude risk for breast cancer was similar in the ART group compared with the general population (hazard ratio (HR) = 1.10, 95% CI, 0.94-1.28) and in the ART group compared with the MAR group (HR = 1.00, 95% CI, 0.86-1.16). Further adjustment for age, BMI, smoking, socioeconomic status and parity did not substantially impact the hazard rates for breast cancer (ART vs general population: HR = 1.10, 95% CI, 0.94-1.28; ART vs MAR: HR = 0.99, 95% CI, 0.85-1.16). Among women diagnosed with breast cancer, the prevalence of BRCA1/2 mutations and tumour staging did not differ between the ART, MAR and general population groups. Among women who underwent ART, no correlation was found between breast cancer and the number of ART cycles or the use of recombinant medications or urine-derived medications.

LIMITATIONS, REASONS FOR CAUTION

The mean age of women at the end of follow-up was only 42 years thus the study was not powered to detect potential differences in the risk of postmenopausal breast cancer. In addition, we did not sub-classify the exposed patients by the reason for infertility.

WIDER IMPLICATIONS OF THE FINDINGS

Breast cancer incidence following ART was comparable to that in the general population or following MAR. Women undergoing fertility treatments and their clinicians may be reassured about the safety of assisted reproduction technologies in terms of premenopausal breast cancer risk.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was used and there are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Association between fertility treatments and breast cancer risk in women with a family history or BRCA mutations: a systematic review and meta-analysis

Women with hereditary breast cancer factors are more likely to be infertile and tend to receive fertility treatments. The safety of fertility treatments that contain hormone-related medications for ovarian stimulation has gained wide attention; however, evidence of the safety of fertility treatments is limited. This study aims to assess the association between fertility treatments and the incidence rate of breast cancer in women with a family history of breast cancer or BRCA mutations. A literature search was conducted in PubMed, Cochrane Library, and Embase. Studies concerning the effect of fertility treatments on breast cancer risk in genetically susceptible women were included. The fixed and random effects models were used to estimate the summary effects. Risk Of Bias In Non-randomized Studies - of Interventions instrument was used to assess the risk of bias in the included studies. A total of 5,282 studies were screened. Five cohort studies and three case-control studies were included. Breast cancer risk was not significantly increased by fertility treatments in general genetically susceptible women [pooled odds ratio (OR) 1.18, 95% confidence interval (CI) 0.96-1.45], women with a family history of breast cancer (pooled OR 1.35, 95% CI 0.97-1.89), or women with BRCA mutations (pooled OR 1.02, 95% CI 0.74-1.4). In subgroup analyses, there was no significant increase in breast cancer risk whether in BRCA1 mutation carriers (pooled OR 1.18, 95% CI 0.81-1.72), BRCA2 mutation carriers (pooled OR 0.54, 95% CI 0.09-3.34), or in the women treated with in vitro fertilization (pooled OR 0.75, 95% CI 0.51-1.1), clomiphene citrate (pooled OR 1.07, 95% CI 0.78-1.45) or gonadotropins (pooled OR 1.32, 95% CI 0.8-2.18). This is the first meta-analysis concerning the impact of fertility treatments on breast cancer risk in genetically susceptible women. Despite the finding that fertility treatment did not significantly increase breast cancer risk in genetically susceptible women, large prospective cohorts with more detailed information are required. Further investigations are needed to explore subtypes of breast cancer, genetic background of hormone-related breast cancer, and the association between BRCA mutations and the incidence of hormone receptor-positive breast cancer.

REGISTRATION NUMBER

PROSPERO(CRD42021281336).