Cost-effectiveness of contralateral prophylactic mastectomy versus routine surveillance in patients with unilateral breast cancer

Purpose: Contralateral prophylactic mastectomy (CPM) rates in women with unilateral breast cancer are increasing despite controversy regarding survival advantage. Current scrutiny of the medical costs led us to evaluate the cost-effectiveness of CPM versus routine surveillance as an alternative contralateral breast cancer (CBC) risk management strategy. Methods: Using a Markov model, we simulated patients with breast cancer from mastectomy to death. Model parameters were gathered from published literature or national databases. Base-case analysis focused on patients with average-risk breast cancer, 45 years of age at treatment. Outcomes were valued in quality-adjusted life-years (QALYs). Patients' age, risk level of breast cancer, and quality of life (QOL) were varied to assess their impact on results. Results: Mean costs of treatment for women age 45 years are comparable: $36,594 for the CPM and $35,182 for surveillance. CPM provides 21.22 mean QALYs compared with 20.93 for surveillance, resulting in an incremental cost-effectiveness ratio (ICER) of $4,869/QALY gained for CPM. To prevent one CBC, six CPMs would be needed. CPM is no longer cost-effective for patients older than 70 years (ICER $62,750/QALY). For BRCA-positive patients, CPM is clearly cost-effective, providing more QALYs while being less costly. In non-BRCA patients, cost-effectiveness of CPM is highly dependent on assumptions regarding QOL for CPM versus surveillance strategy. Conclusion: CPM is cost-effective compared with surveillance for patients with breast cancer who are younger than 70 years. Results are sensitive to BRCA-positive status and assumptions of QOL differences between CPM and surveillance patients. This highlights the importance of tailoring treatment for individual patients.