Treatment patterns and oncologic outcomes of breast-conserving surgery: a multicenter real-world retrospective cohort study in Zhejiang, China
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background: Breast-conserving surgery (BCS) is supported by randomized trials conducted in selected populations, but less is known about how BCS and its associated treatments are delivered in routine practice and what outcomes are achieved outside trial settings. This study aimed to describe the treatment patterns and oncologic outcomes of patients undergoing BCS in six hospitals in Zhejiang Province, China, and to identify gaps between guideline-recommended and delivered care. Methods: This multicenter retrospective cohort study included female patients aged ≥18 years with breast cancer who underwent BCS between January 2014 and December 2019. Patients with concurrent primary malignancy, bilateral breast cancer, conversion to mastectomy, participation in anticancer clinical trials, or incomplete key data were excluded. Data were extracted from medical records, pathology reports, operative notes, and radiotherapy records using a standardized case report form, and survival status was ascertained through outpatient records and telephone follow-up. Recurrence-free interval (RFI), disease-free survival (DFS), overall survival (OS), and surgical, drug-related, and radiotherapy-related adverse events (AEs) were evaluated. Survival was estimated using the Kaplan-Meier method, and between-group comparisons were exploratory and unadjusted. Results: A total of 2,206 patients were included (median age, 50.8 years); 91.4% had stage I-II disease and 84.0% had a single lesion. Conventional BCS was performed in 95.8% and oncoplastic BCS in 4.2% of patients, and 75.0% received adjuvant radiotherapy. Among patients with 1-2 sentinel lymph node (SLN) metastases, axillary lymph node dissection (ALND) was omitted in 52.4%. With a median follow-up of 5.43 years, local recurrence and distant metastasis occurred in 2.4% and 3.2% of patients, respectively. The 5-year RFI, DFS, and OS rates were 95.4% [95% confidence interval (CI): 94.5-96.4%], 94.2% (95% CI: 93.1-95.2%), and 97.8% (95% CI: 97.1-98.4%), respectively. In unadjusted analyses, no significant differences in RFI, DFS, or OS were observed between conventional and oncoplastic BCS or between single and multiple lesions. Conclusions: In this regional multicenter cohort of patients selected for BCS, 5-year oncologic outcomes were favorable. Approximately one quarter of patients did not receive adjuvant radiotherapy, and ALND omission in patients with limited nodal burden was incompletely adopted, indicating gaps between guideline recommendations and routine practice. Because treatment was not randomly assigned and comparisons were unadjusted, the subgroup findings should be regarded as hypothesis-generating.
Source: Gland Surgery
Language: English
Subfield: Cancer Research
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W7223979811