Ovarian toxicity of carboplatin and paclitaxel in mouse carriers of mutation in BRIP1 tumor suppressor gene

Pregnancy After Breast Cancer in Young BRCA Carriers: An International Hospital-Based Cohort Study

Importance

Young women with breast cancer who have germline pathogenic variants in BRCA1 or BRCA2 face unique challenges regarding fertility. Previous studies demonstrating the feasibility and safety of pregnancy in breast cancer survivors included limited data regarding BRCA carriers.

Objective

To investigate cumulative incidence of pregnancy and disease-free survival in young women who are BRCA carriers.

Design, Setting, and Participants

International, multicenter, hospital-based, retrospective cohort study conducted at 78 participating centers worldwide. The study included female participants diagnosed with invasive breast cancer at age 40 years or younger between January 2000 and December 2020 carrying germline pathogenic variants in BRCA1 and/or BRCA2. Last delivery was October 7, 2022; last follow-up was February 20, 2023.

Exposure

Pregnancy after breast cancer.

Main Outcomes and Measures

Primary end points were cumulative incidence of pregnancy after breast cancer and disease-free survival. Secondary end points were breast cancer-specific survival, overall survival, pregnancy, and fetal and obstetric outcomes.

Results

Of 4732 BRCA carriers included, 659 had at least 1 pregnancy after breast cancer and 4073 did not. Median age at diagnosis in the overall cohort was 35 years (IQR, 31-38 years). Cumulative incidence of pregnancy at 10 years was 22% (95% CI, 21%-24%), with a median time from breast cancer diagnosis to conception of 3.5 years (IQR, 2.2-5.3 years). Among the 659 patients who had a pregnancy, 45 (6.9%) and 63 (9.7%) had an induced abortion or a miscarriage, respectively. Of the 517 patients (79.7%) with a completed pregnancy, 406 (91.0%) delivered at term (≥37 weeks) and 54 (10.4%) had twins. Among the 470 infants born with known information on pregnancy complications, 4 (0.9%) had documented congenital anomalies. Median follow-up was 7.8 years (IQR, 4.5-12.6 years). No significant difference in disease-free survival was observed between patients with or without a pregnancy after breast cancer (adjusted hazard ratio, 0.99; 95% CI, 0.81-1.20). Patients who had a pregnancy had significantly better breast cancer-specific survival and overall survival.

Conclusions and Relevance

In this global study, 1 in 5 young BRCA carriers conceived within 10 years after breast cancer diagnosis. Pregnancy following breast cancer in BRCA carriers was not associated with decreased disease-free survival.

Trial Registration

ClinicalTrials.gov Identifier: NCT03673306.

BRCA Mutations and Fertility Preservation

Hereditary cancers mostly affect the adolescent and young adult population (AYA) at reproductive age. Mutations in BReast CAncer (BRCA) genes are responsible for the majority of cases of hereditary breast and ovarian cancer. BRCA1 and BRCA2 act as tumor suppressor genes as they are key regulators of DNA repair through homologous recombination. Evidence of the accumulation of DNA double-strand break has been reported in aging oocytes, while BRCA expression decreases, leading to the hypothesis that BRCA mutation may impact fertility. Moreover, patients exposed to anticancer treatments are at higher risk of fertility-related issues, and BRCA mutations could exacerbate the treatment-induced depletion of the ovarian reserve. In this review, we summarized the functions of both genes and reported the current knowledge on the impact of BRCA mutations on ovarian ageing, premature ovarian insufficiency, female fertility preservation strategies and insights about male infertility. Altogether, this review provides relevant up-to-date information on the impact of BRCA1/2 mutations on fertility. Notably, BRCA-mutated patients should be adequately counselled for fertility preservation strategies, considering their higher sensitivity to chemotherapy gonadotoxic effects.

Does the addition of metformin to carboplatin treatment decreases ovarian reserve damage associated with carboplatin usage?

BACKGROUND

We aimed to determine whether adding metformin to carboplatin treatment would reduce the damage to ovarian reserve associated with carboplatin use.

METHODS

We included 35 adult female non-pregnant albino Wistar rats approximately three months old, weighing 220-310 g. The rats were divided into five groups of seven rats according to the treatment they received. Carboplatin and salin was given to Group 2, and carboplatin plus metformin was given to Group 3. Group 4 was administered only metformin. Group 5 was administered only salin. Carboplatin was given to Groups 2 and 3 as a single dose on the 15th day, while metformin was given to Groups 3 and 4 during the 28-day experiment. After oophorectomy, histopathologic analyses of primordial, primary, secondary, and tertiary Graff follicles according to the epithelial cells surrounding the oocyte and total follicular number were conducted per section. Serum Anti-Mullerian Hormone (AMH), tissue catalase, and malonyl dialdehyde levels were measured and compared within each group.

RESULTS

The baseline and 15th-day serum AMH values of the menstrual cycle were compared among the groups, and no statistically significant differences were observed (p > 0.05). Group 3, which was given both carboplatin and metformin, had statistically significantly higher 28th-day AMH levels than Group 2, which was given only carboplatin and saline (p < 0.001). The number of primordial follicles in Group 3 was found to be statistically significantly higher than in Group 2 (p < 0.001). Tissue catalase enzyme levels in Group 3 were statistically significantly higher than in Group 2 (p < 0.001). Tissue malondialdehyde levels in Group 2 were statistically significantly higher than tissue malondialdehyde levels in Groups 3 and 4 (p < 0.001).

CONCLUSIONS

Metformin may attenuate carboplatin-induced ovarian damage, possibly through its antioxidative effects.

BRCA, infertility, and fertility preservation: a review for counseling

BRCA mutations as a triggering factor in breast cancer have been reported to result in fertility problems and oocyte aging in young patients with cancer diagnosis. These patients are concerned about fertility problems and family planning before undergoing treatment modalities that may result in infertility. In this review, we conducted analysis of the literature on the association between BRCA mutations and infertility, possible fertility preservation options, and their safety and tried to gather results from different disciplines and points of view on the matter. Our aim is to provide a general summary of recent studies to provide further insight on the matter for counseling BRCA mutation carriers on fertility preservation methods and their implications.