# Decisional Conflict About Contralateral Prophylactic Mastectomy in Patients with Breast Cancer with and Without Pathogenic Variants in BRCA Genes

## TL;DR

This study finds that many breast cancer patients, especially those without BRCA mutations, experience decisional conflict when considering contralateral mastectomy, highlighting the importance of shared decision-making.

## Contribution

The study identifies factors influencing decisional conflict in Korean breast cancer patients with and without BRCA mutations, emphasizing the role of shared decision-making.

## Key findings

- Over 75% of patients experienced clinically significant decisional conflict, with non-carriers reporting higher conflict than BRCA carriers.
- Lower shared decision-making scores were strongly associated with higher decisional conflict in both BRCA carriers and non-carriers.
- Among BRCA carriers, preference for passive decision-making roles was linked to higher decisional conflict.

## Abstract

Breast cancer patients may consider contralateral prophylactic mastectomy to reduce the risk of cancer in the opposite breast, especially if they have a genetic predisposition to the disease. However, this complex decision may lead to decisional conflict. This study examined decisional conflict and its associated factors among 167 Korean patients with breast cancer who had genetic testing, comparing differences between patients with and without a pathogenic variant in one of the BRCA genes. More than three-quarters of patients experienced clinically significant decisional conflict, particularly non-carriers and those who were less engaged in shared decision making. Among BRCA carriers, preference for passive roles in decision making was associated with higher decisional conflict, whereas no significant factors were identified among non-carriers. Findings suggest that decisional conflict is influenced not only by genetic risk but also by the quality of the decision-making process. Strengthening shared decision making and supporting patient engagement may improve decision-making experiences.

Background/Objectives: Decision making for contralateral prophylactic mastectomy in patients with breast cancer involves complex risk–benefit trade-offs that may lead to decisional conflict. Understanding factors associated with decisional conflict, particularly for patients with pathogenic variants in BRCA genes, is critical for developing tailored decisional support. This study examined decisional conflict, shared decision making, and decisional role preferences in Korean patients with breast cancer considering contralateral prophylactic mastectomy, focusing on factors associated with clinically significant decisional conflict and differences by BRCA status. Methods: A cross-sectional, internet-based survey was conducted between August and October 2024. Independent t-tests, univariate, and multivariate logistic regression analyses identified factors associated with clinically significant decisional conflict. Results: The sample included 167 Korean patients with breast cancer (90 BRCA carriers and 77 non-carriers). Most patients (76%) experienced clinically significant decisional conflict. Non-carriers reported higher decisional conflict (44.2 vs. 29.3, p < 0.001) and lower shared decision making than BRCA carriers (44.6 vs. 61.9, p < 0.001). Role preferences were similarly distributed across groups (50.3% active, 24.0% collaborative, 25.7% passive). In multivariable analysis, clinically significant decisional conflict in the total sample was associated with non-carrier status (OR = 2.98) and lower shared decision-making scores (OR = 0.94) (p < 0.05), explaining 28% of the variance. Among BRCA carriers, clinically significant decisional conflict was associated with lower shared decision-making scores (OR = 0.92) and passive role preferences (vs. active) (OR = 4.88). No variables were significantly associated with decisional conflict among non-carriers. Conclusions: Findings suggest that decisional conflict is influenced by genetic risk and the quality of the decision-making process. Improving patient engagement by identifying preferred decisional roles, understanding the reasons behind these preferences, and encouraging shared decision making may help reduce decisional conflict, particularly among BRCA carriers. Further research is needed to better understand factors associated with decisional conflict among non-carriers.