Prognosis and Decision-making Analysis of Contralateral Prophylactic Mastectomy among female patients with stage 0–III unilateral breast cancer in Chinese population: a retrospective cohort study
Authors: zhu jingjin , min ningning , zhang yanjun , wu huan , hong chenyan , geng rui , wei yufan , guan qingyu , zheng yiqiong , li xiru 
Published: August 2023

Abstract
Purpose
It was demonstrated that contralateral prophylactic mastectomy (CPM) provides no survival benefit for patients with average risk breast cancer, but the application in patients with early-stage breast cancer has increased. This study aims to explore the application trend, survival benefits, decision-making factors, and satisfaction of CPM based on the patients undergoing CPM in a Chinese institution.
Methods
The 0-III stage unilateral breast cancer (UBC) patients who received breast surgery in the First Medical Center of the PLA General Hospital from 2005 to 2017 were selected. The surgical procedures include simple mastectomy (SM), nipple-sparing mastectomy (NSM) and breast conserving surgery (BCS). Those patients who underwent preventive breast surgery on the healthy side were defined as the CPM group. The Cochran Armitage trend test was used to compare the longitudinal application trend of the annual surgical number and proportion of the four surgical procedures. Cox proportional regression analysis and Kaplan-Meier curve were performed to compare the overall survival (OS) and disease free survival (DFS) rates between CPM group and unilateral mastectomy (UM) group. Proportional propensity score matching (PSM) with a 1:1 ratio was used to match the two groups and secondary survival analysis was performed. Logistic regression models were used to test predictive factors related to patients' CPM surgical decision-making. A self-made satisfaction rating scale were used to analyze the satisfaction of CPM procedure and the impact on quality of life.
Results
4,276 patients were included in the study, with 73 (1.7%) patients receiving CPM, 3567 (83.4%) receiving SM, 151 (35.3%) receiving NSM, and 485 (11.3%) receiving BCS. CPM surgery was first used in 2007, with a peak application rate of 3.02% in 2016 and a decrease to 1.05% in 2017. 3,791 patients with CPM and UM were included in the survival analysis, with a median follow-up time of 66.60 months. Compared to UM patients, neither the KM survival curve nor Cox regression hazard analysis of CPM showed better OS (p = 0.963; p = 0.834). After PSM, CPM also did not exhibit significant survival benefits in OS (HR 0.876, 95% CI 0.253–3.034, p = 0.335) and DFS (HR 0.922, 95% CI 0.629–1.352, p = 0.409). The logistic regression analysis showed that NSM surgery and early TNM stage were independent factors to promote the CPM decision-making of patients. 73 patients in the CPM group showed high overall satisfaction (84.9%) and relatively low physical satisfaction (69.9%). And a significant percentage of patients expressed that the physical labor was affected.
Conclusion
Our study suggested CPM does not provide any OS and DFS survival benefits compared to UM. Although most patients with CPM were generally satisfied, many gave a low evaluation of cosmetic results. Therefore, clinicians should fully communicate with patients before surgery and be more cautious in giving CPM recommendations.