Safety Analysis of Omitting Radiotherapy After Breast-Conserving Surgery in Patients With Early-Stage Breast Cancer: A Meta-Analysis Based on Randomized Controlled Trials.

Background and objectives: The safety of omitting radiotherapy (RT) after breast-conserving surgery (BCS) in patients with early-stage breast cancer (BC) remains controversial. This study investigates the safety of omitting RT after BCS.

Methods: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search of PubMed, Web of Science, EMBASE, and the Cochrane Library to identify eligible randomized controlled trials (RCTs). The primary outcomes were local recurrence (LR) and overall survival (OS), while secondary outcomes included distant metastasis (DM), disease-free survival (DFS), and disease-specific survival (DSS). The analysis was conducted using hazard ratios (HRs) and 95% confidence intervals (CIs).

Results: A total of 14 RCTs involving 11 977 early-stage BC patients who underwent BCS were included in this meta-analysis. Compared with patients who received RT, those who omitted RT had a significantly higher LR (HR = 2.76; p < 0.001), but no significant difference was observed in OS between the two groups (HR = 1.05; p = 0.208). The DFS was significantly better in the RT group than in the no-RT group (HR = 1.29; p = 0.001). No significant differences were observed between the two groups in DM (HR = 0.96; p = 0.729) or DSS (HR = 1.03; p = 0.754). Subgroup analyses revealed that omitting RT was associated with a higher LR across different follow-up periods, age stratifications, and types of BC invasiveness, but no significant impact on OS was found.

Conclusions: This study found that in patients with early-stage BC, omitting RT after BCS increased the LR compared with the RT group, but did not affect the OS.

Trial registration: PROSPERO (CRD420250655104).