- Postmastectomy radiotherapy (PMRT) boosts OS in patients with triple-negative breast cancer (TNBC) with T1-2 tumors and 1-3 positive lymph nodes (N1-3).
Why this matters
- PMRT is standard of care for patients with ≥4 axillary lymph nodes, but use in N1-3 disease remains controversial.
- Findings are strong enough to warrant a prospective study.
- Population-based retrospective cohort of 675 patients with T1-2, N1-3 TNBC in the Surveillance, Epidemiology, and End Results database, 2010-2012.
- 312 underwent PMRT and 363 did not.
- Funding: National Natural Science Foundation of China; the Wu Jieping Medical Foundation.
- Median follow-up, 37 months.
- Kaplan-Meier analysis: PMRT improved OS (P=.033), but not breast cancer-specific survival (BCSS; P=.063).
- Multivariate Cox proportional hazards model: PMRT improved OS (HR, 0.661; P=.025) and BCSS (HR, 0.664; P=.039).
- No significant differences in OS or BCSS were found in either analysis when stratified by the number of positive lymph nodes.
- Observational, retrospective design.
- No data on locoregional recurrence.