Risk-Reducing Salpingo-Oophorectomy and Breast Cancer Risk Reduction in the Gynecologic Oncology Group Protocol-0199 (GOG-0199)

Systemic and Local Strategies for Primary Prevention of Breast Cancer

One in eight women will develop breast cancer in the US. For women with moderate (15-20%) to average (12.5%) risk of breast cancer, there are few options available for risk reduction. For high-risk (>20%) women, such as BRCA mutation carriers, primary prevention strategies are limited to evidence-based surgical removal of breasts and/or ovaries and anti-estrogen treatment. Despite their effectiveness in risk reduction, not many high-risk individuals opt for surgical or hormonal interventions due to severe side effects and potentially life-changing outcomes as key deterrents. Thus, better communication about the benefits of existing strategies and the development of new strategies with minimal side effects are needed to offer women adequate risk-reducing interventions. We extensively review and discuss innovative investigational strategies for primary prevention. Most of these investigational strategies are at the pre-clinical stage, but some are already being evaluated in clinical trials and others are expected to lead to first-in-human clinical trials within 5 years. Likely, these strategies would be initially tested in high-risk individuals but may be applicable to lower-risk women, if shown to decrease risk at a similar rate to existing strategies, but with minimal side effects.

Bilateral Oophorectomy and the Risk of Breast Cancer in BRCA1 Mutation Carriers: A Reappraisal

BACKGROUND

The lack of consensus on whether bilateral oophorectomy impacts risk of developing breast cancer among BRCA1 mutation carriers might be attributed to various biases, specifically, cancer-induced testing bias due to inclusion of prevalent cases. We conducted two complementary matched case-control analyses to evaluate the association of oophorectomy and BRCA1 breast cancer.

METHODS

A research questionnaire was administered every two years to collect information on exposures and disease. In the first analysis, we limited the study to prevalent breast cancer cases (diagnosed prior to study entry; n = 2,962) who were matched to controls on year of birth and country of residence (n = 4,358). In the second approach, we limited to 330 incident cases (diagnosed in the follow-up period) and 1,548 matched controls. Conditional logistic regression was used to estimate the adjusted odds ratios (OR) and 95% confidence intervals (CI) of invasive breast cancer.

RESULTS

In the first approach, there was a significant inverse association between oophorectomy and the risk of developing breast cancer [OR = 0.43; 95% confidence interval (CI), 0.34-0.55; P < 00001]. In the second approach, there was no association between oophorectomy and risk (OR = 1.21; 95% CI, 0.87-1.70; P = 0.26).

CONCLUSIONS

The inclusion of women with a personal history of breast cancer prior to ascertainment likely impacts upon the association of oophorectomy and BRCA1 breast cancer risk.

IMPACT

Oophorectomy is unlikely a determinant of breast cancer risk in BRCA1 mutation carriers but should be offered at age 35 to reduce the risk of ovarian and fallopian tube cancer.

Bilateral Salpingo-oophorectomy and Breast Cancer Risk for BRCA1 and BRCA2 Mutation Carriers: Assessing the Evidence

Without preventive interventions, women with germline pathogenic variants in BRCA1 or BRCA2 have high lifetime risks for breast cancer and tubo-ovarian cancer. The increased risk for breast cancer starts at a considerably younger age than that for tubo-ovarian cancer. Risk-reducing bilateral salpingo-oophorectomy (rrBSO) is effective in reducing tubo-ovarian cancer risk for BRCA1 and BRCA2 mutation carriers, but whether it reduces breast cancer risk is less clear. All studies of rrBSO and breast cancer risk are observational in nature and subject to various forms of bias and confounding, thus limiting conclusions that can be drawn about causation. Early studies supported a statistically significant protective association for rrBSO on breast cancer risk, which is reflected by several international guidelines that recommend consideration of premenopausal rrBSO for breast cancer risk reduction. However, these historical studies were hampered by the presence of several important biases, including immortal person-time bias, confounding by indication, informative censoring, and confounding by other risk factors, which may have led to overestimation of any protective benefit. Contemporary studies, specifically designed to reduce some of these biases, have yielded contradictory results. Taken together, there is no clear and consistent evidence for a role of premenopausal rrBSO in reducing breast cancer risk in BRCA1 or BRCA2 mutation carriers.

Satisfaction with prophylactic risk-reducing salpingo-oophorectomy in BRCA mutation carriers is very high and little dependent on the participants' characteristics at surgery: a prospective study

OBJECTIVE

BRCA carriers are recommended to undergo prophylactic risk-reducing salpingo-oophorectomy (RRSO). Possible adverse health impacts of RRSO, particularly when done before natural menopause, can reduce the long-term satisfaction with this risk-reducing strategy. The aim of this study was to prospectively evaluate the level of satisfaction of women undergoing RRSO, also in relation to some specific characteristics at RRSO.

METHODS

A prospective cohort study was performed in the Modena Family Cancer Clinic of the University Hospital of Modena (Italy). All BRCA1/2 confirmed mutation carriers who decided to undergo RRSO were recruited between 2016 and 2019.

RESULTS

Fifty-five women (29 BRCA1 and 26 BRCA2) (mean age: 50.4 ± 7.7 years [range 35-79]) were included with a mean follow-up after RRSO of 660.9 days (1.8 years) (range 35-1,688 days) (median: 549 days). No intraepithelial (Serous Tubal Intraepithelial Carcinoma)/invasive cancers were found (0%) at RRSO. No vasomotor symptoms at 1 month after surgery were reported by 11/22 (50%) premenopausal women at RRSO. All women (100%) with new "RRSO-caused" vasomotor symptoms with no previous breast cancer initiated postmenopausal hormone therapy. At the final follow-up the satisfaction rate (0-100 visual analog scale points) of the participants was 96.4 ± 8.6 points (range 62-100). To the question "Would you undergo RRSO again if it was proposed today? (0-100 visual analog scale points)" the answer was 99.4 ± 3.2 points (range 79-100). These scores were in general very high and did not change in the different groups according to pre/postmenopausal status at RRSO, cancer survivors versus healthy women at RRSO, BRCA status, hormone therapy users/nonusers after RRSO, "RRSO-caused" symptoms versus not RRSO-caused (P > 0.05).

CONCLUSIONS

Findings from this prospective study suggest that satisfaction with RRSO is very high and little dependent on the participants' characteristics at surgery. Women at high risk for ovarian cancer are very satisfied with their choice of risk-reduction strategy.

Should the risk for uterine cancer influence decision making for prophylactic hysterectomy in BRCA1/2 mutated patients- a systematic review and meta-analysis

OBJECTIVE

To study the possible association between uterine cancer and the BRCA1/2 associated cancer syndrome and discuss the implications of such an association on the clinical managment of patients with BRCA1/2 mutations.

METHODS

A systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. Study protocol was prospectively registered at PROSPERO International prospective register of systematic reviews (registration number CRD42020193496). Considered for inclusion were studies providing the diagnosis rate of uterine cancer in patients with BRCA1/2 mutations by comparing observed and expected rate according to a known disease incidence. The results were measured by standardized incidence ratio (SIR). The primary outcome was defined as any uterine cancer diagnosis and subgroup analyses were conducted for uterine serous papillary cancer (USPC) specifically and for BRCA1 and BRCA2 mutations separately.

RESULTS

4591 records were identified through database search; eight studies were finally included, comprising 13,098 patients with BRCA1/2 mutations. BRCA1/2 mutated patients were found to have a significantly higher risk for uterine cancer compared to the general population (SIR = 2.22, 95% CI 1.76-2.8, p < 0.001). A higher incidence of USPC was also found in patients with BRCA1/2 mutations (SIR = 17.97, 95% CI 9.89-32.66, p < 0.001), as well as in a separate analysis for BRCA1 (SIR = 2.81, 95% CI 2.09-3.79, p < 0.001) and BRCA2 (SIR = 1.75, 95% CI 1.09-2.80, p < 0.001) mutations.

CONCLUSION

Patients who carry a BRCA1/2 mutation are at a significantly higher risk of developing uterine cancer, specifically USPC, supporting that USPC may be a component of the BRCA1/2 syndrome. The decision to perform concurrent hysterectomy at the time of the risk reduction bilateral salpingo -oophorectomy surgery should be considered individually.

Key steps for effective breast cancer prevention

Despite decades of laboratory, epidemiological and clinical research, breast cancer incidence continues to rise. Breast cancer remains the leading cancer-related cause of disease burden for women, affecting one in 20 globally and as many as one in eight in high-income countries. Reducing breast cancer incidence will likely require both a population-based approach of reducing exposure to modifiable risk factors and a precision-prevention approach of identifying women at increased risk and targeting them for specific interventions, such as risk-reducing medication. We already have the capacity to estimate an individual woman's breast cancer risk using validated risk assessment models, and the accuracy of these models is likely to continue to improve over time, particularly with inclusion of newer risk factors, such as polygenic risk and mammographic density. Evidence-based risk-reducing medications are cheap, widely available and recommended by professional health bodies; however, widespread implementation of these has proven challenging. The barriers to uptake of, and adherence to, current medications will need to be considered as we deepen our understanding of breast cancer initiation and begin developing and testing novel preventives.

Postmenopausal hormone therapy in BRCA gene mutation carriers: to whom and which?

INTRODUCTION

Risk-reducing-salpingo-oophorectomy (RRSO) inevitably leads BRCA mutation carriers to premature menopause.

AREAS COVERED

To evaluate the existing evidence for use of postmenopausal hormone therapy (HT) in BRCAmc, after RRSO or menopause occurring naturally, for both breast cancer (BC) survivors and those without BC.

EXPERT OPINION

All BC survivors are excluded from any HT treatment: in other BRCAmc, before 51 years of age the benefits of HT overcome the risks after RRSO and/or premature ovarian insufficiency (POF). After 51 years of age, it is important to treat only women with important vasomotor symptoms, after the failure of alternative therapies. Estrogens-only therapy plays a key role in hysterectomized women (HW). In the case of an intact uterus (UW), associations with the lowest dose of progestins/natural progesterone derivatives have to be preferred, as progestins has been shown to play an important role in BC transformation, especially in BRCA1mc. No studies have been performed in BRCAmc with regard to 'progestin-free' HT, in particular the old tibolone (both in HW and UW) and the new tissue-selective estrogen complex (in UW). However, preliminary data obtained from the general population are reassuring about the use of these 'progestin-free' preparations and BC safety.