To investigate the application of selective cavity shaving margins (CSM) method combined with intraoperative froze-section pathology in breast-conserving surgery (BCS) of breast cancer patients.

A retrospective analysis of clinical data was conducted on 303 breast cancer patients who underwent BCS using the CSM and intraoperative frozen-section pathological evaluation of margins by the same group of surgeons in the Xuanwu Hospital of Capital Medical University from January 2006 to December, 2014, and in the Beijing Tsinghua Changgung Hospital from January, 2015 to December 2021. The Kaplan-Meier method was used to calculate the cumulative local recurrence-free survival (LRFS), DFS and OS of patients. Univariate analysis was used to compare the local recurrence rates between patients with different clinicopathological factors, and the log-rank test was used to compare the effects of different factors on local recurrence.

Totally 303 BCS patients were followed up for median 119 months (range: 23 to 211 months), and 11 cases experienced local recurrence, with a median recurrence time of 30 months (range: 5 to 60 months). The 5-year LRFS, DFS and OS of 303 patients were 95.9%, 95.0%, and 97.8%, respectively; the 10-year LRFS, DFS and OS were 95.9%, 93.2%, and 96.6%, respectively, with a 10-year cumulative local recurrence rate of 4.1%. The 10-year cumulative local recurrence rates of patients with in situ carcinoma and invasive carcinoma were 14.3% and 2.9%, respectively, indicating a significant difference (χ²=9.490, P=0.002). The patients with in situ carcinoma showed a significantly higher risk compared with patients with invasive carcinoma (HR=5.539, 95%CI: 1.45-35.83).

The intraoperative CSM method is a safe and feasible approach in BCS of early-stage breast cancer. It not only significantly reduces the possibility of reoperation but also maintains a low rate of local recurrence.