Abstract
Purpose
The application of postmastectomy radiotherapy (PMRT) in T1–2 female breast cancer patients with 1–3 positive lymph nodes has been controversial. We sought to determine the survival benefits of PMRT in the patients with T1–2 and 1–3 positive nodes.
Methods
A retrospective study using the Surveillance, Epidemiology, and End Results (SEER) Regs Custom Data (with additional treatment fields) from 2001 to 2011 was performed. Patients who received PMRT were matched by the propensity score with patients who did not receive PMRT. The Overall survival (OS) and breast cancer-specific survival (BCSS) were analyzed.
Results
We identified 56,725 female breast cancer patients with T1–2 and 1–3 positive nodes, and 18,646 patients were included in the analysis. After propensity score matching (1:1), with a median follow-up of 116 months, PMRT showed an increase in the OS (P = 0.018) but had no effect on the BCSS. The 10-year OS rates were 76.8% and 74.4%, and the 10-year BCSS rates were 82.8% and 82.2% for the patients who received and who did not receive PMRT, respectively. Only patients with 3 positive nodes could gain the benefit of PMRT for BCSS.
Conclusion
PMRT for patients with T1–2 and 1–3 positive lymph nodes could increase the 10-year OS, and had no effect on the 10-year BCSS. Subgroup analysis indicated that only patients with 3 positive lymph nodes could benefit from PMRT for both the OS and BCSS.