Methods This study was a retrospective cohort study. The clinical data of 168 breast cancer patients with isolated locoregional recurrence after mastectomy in the Fourth Hospital of Hebei Medical University from January 2011 to December 2020 were retrospectively analyzed. According to local intervention (surgery/radiotherapy) after locoregional recurrence, all patients were divided into two groups: intervention group (115 cases) and non-intervention group (53 cases). Kaplan-Meier method and log-rank test were used to compare the 5-year locoregional control (LRC), distant metastasis-free survival (DMFS), progression-free survival (PFS) and overall survival (OS) in univariate analysis. The Cox proportional risk regression model was used for multivariate survival analysis.
Results The median follow-up time was 53 months (12.0-121.0 months). Secondary local recurrence occurred in 28 cases (16.7%), distant metastasis occurred in 59 cases (35.1%), and death occurred in 59 cases (35.1%). Univariate analysis demonstrated that 5-year LRC(59.6% vs 40%, χ2=9.550, P=0.002), DMFS(60.4% vs 32.2%, χ2= 10.828, P=0.001), PFS(57.9% vs 28.0%, χ2= 18.342, P<0.001), OS(61.6% vs 44.9%, χ2=4.176, P=0.041) in intervention group were significantly higher than those in non-intervention group. Multivariate analysis revealed that local intervention was an independent prognostic factor for 5-year LRC(HR=2.097, 95%CI: 1.287-3.417, P=0.003), DMFS(HR=2.296, 95%CI: 1.340-3.933, P=0.002), PFS(HR=2.280, 95%CI: 1.440-3.611, P=0.000) and OS(HR=1.881, 95%CI: 1.049-3.374, P=0.034). Subgroup analysis showed that for patients with regional recurrence, 5-year LRC(64.9% vs 35.7%, χ2= 8.807, P=0.003), DMFS(61.1% vs 27.6%, χ2= 8.283, P=0.004), PFS(61.6% vs 26.4%, χ2= 9.549, P=0.002) and OS (64.9% vs 38.8%, χ2=5.916, P=0.015) in intervention group were significantly higher than those in non-intervention group, while there was no statistically significant difference between two groups in patients with local recurrence and patients with both local recurrence and regional recurrence. There was no significant difference in 5-year LRC(69.2% vs 58.5% vs 53.3%, χ2= 1.914, P=0.384), DMFS(65.1% vs 58.0% vs 66.0%, χ2= 1.996, P=0.374), PFS(65.1% vs 57.0% vs 53.3%, χ2= 1.867, P=0.393)and OS(69.2% vs 58.5% vs 66.0%, χ2=1.048, P=0.592) among surgery combined with radiotherapy group, radiotherapy group and surgery group.