Objective Women carrying a BRCA1/2 pathogenic variant have an increased risk for breast cancer and may opt for risk‐reducing bilateral mastectomy. In this study, we examine which demographic, psychosocial, and personality factors are associated with their decision to undergo risk‐reducing bilateral mastectomy. Methods Cancer‐unaffected women with a pathogenic variant in BRCA1 or BRCA2 were recruited before receiving their genetic test result and completed follow‐up including decision to undergo mastectomy over 6–8 months after genetic test result disclosure. Anxiety, depression, breast cancer worry, personality and sociodemographic data were assessed. Results A total of 125 cancer‐unaffected women were included in the analysis. Participants were found to have higher anxiety levels than the general female population regardless of mastectomy decision. Breast cancer worry was higher among women who opted for risk‐reducing mastectomy and did not decrease over time. By contrast, women who did not opt for surgery experienced decreasing levels of breast cancer worry. Regression analysis found that women with a pathogenic variant in BRCA1, younger women and women with higher breast cancer worry were more likely to opt for surgery. Conclusions Our study provides valuable insights into the factors that influence women with a BRCA1/2 pathogenic variant to undergo risk‐reducing mastectomy. These findings may be helpful in understanding individual differences in decision‐making concerning preventive options and show the need to address negative anticipatory feelings associated with carrying a pathogenic variant in a high breast cancer risk gene in clinical care.

Counseling for familial breast cancer focuses on communicating the gene test result (GENE) to counselees, but risk prediction models have become more complex by including non-genetic risk factors (NGRF) and polygenic risk scores (PRS). We examined genetic clinicians' confidence in counseling and counselees' psychosocial outcomes, using the BOADICEA risk prediction tool with different categories of risk factors as input. A prospective observational study in Dutch, French and German genetic clinics was performed including 22 clinicians, and 406 of 460 (88.3%) eligible cancer-unaffected women at high breast cancer risk assessed at pre-test and 350 (76.1%) at post-test. We performed multilevel analyses accounting for the clinician, and counselees' characteristics. Overall, risk estimates category by GENE versus GENE+ NGRF, or GENE+NGRF+PRS differed in 11% and 25% of counselees, respectively. In multilevel analyses, clinicians felt less confident in counseling when

Background Women carrying BRCA1/2 pathogenic variants are exposed to elevated risks of developing breast cancer (BC) and are faced by a complex decision-making process on preventative measures, i.e., risk-reducing mastectomy (RRM), and intensified breast surveillance (IBS). In this prospective cohort study we investigated the effect of anxiety, personality factors and coping styles on the decision-making process on risk management options in women with pathogenic variants in BRCA1/2. Methods Breast cancer unaffected and affected women with a pathogenic variant in the BRCA1 or BRCA2 gene were psychologically evaluated immediately before (T0), 6 to 8 weeks (T1) and 6 to 8 months (T2) after the disclosure of their genetic test results. Uptake of RRM and IBS was assessed at T2. Psychological data were gathered using questionnaires on risk perception, personality factors, coping styles, decisional conflict, depression and anxiety, including the Hospital Anxiety and Depression Scale (HADS). We performed tests on statistical significance and fitted a logistic regression based on significance level. Results A total of 98 women were included in the analysis. Baseline anxiety levels in women opting for RRM were high but decreased over time, while they increased in women opting for intensified breast surveillance (IBS). Elevated levels of anxiety after genetic test result disclosure (T1) were associated with the decision to undergo RRM (p < 0.01; OR = 1.2, 95% CI = 1.05–1.42), while personal BC history and personality factors seemed to be less relevant. Conclusions Considering psychosocial factors influencing the decision-making process of women with pathogenic variants in BRCA1/2 may help improving their genetic and psychological counselling. When opting for IBS they may profit from additional medical and psychological counselling. Trial registration Retrospectively registered at the German Clinical Trials Register under DRKS00027566 on January 13, 2022.