Locoregional recurrence risk for patients with T1,2 breast cancer with 1-3 positive lymph nodes treated with mastectomy and systemic treatment.

Purpose: Postmastectomy radiation therapy (PMRT) has been shown to benefit breast cancer patients with 1 to 3 positive lymph nodes, but it is unclear how modern changes in management have affected the benefits of PMRT.

Methods And Materials: We retrospectively analyzed the locoregional recurrence (LRR) rates in 1027 patients with T1,2 breast cancer with 1 to 3 positive lymph nodes treated with mastectomy and adjuvant chemotherapy with or without PMRT during an early era (1978-1997) and a later era (2000-2007). These eras were selected because they represented periods before and after the routine use of sentinel lymph node surgery, taxane chemotherapy, and aromatase inhibitors.