Locoregional Recurrence of Triple-negative Breast Cancer After Breast-conserving Surgery and Radiation

BACKGROUND: The results of radiation on the local control of triple receptor-negative breast cancer (negative estrogen [ER], progesterone [PR], and HER-2/neu receptors) was studied. METHODS: Conservative surgery and radiation were used in 753 patients with T1-T2 breast cancer. Three groups were defined by receptor status: Group 1: ER or PR (+); Group 2: ER and PR (-) but HER-2 (+); and Group 3: triple-negative (TN). Factors analyzed were age, menopausal status, race, stage, tumor size, lymph node status, presentation, grade, extensive in situ disease, margins, and systemic therapy. The primary endpoint was 5-year locoregional recurrence (LRR) isolated or total with distant metastases. RESULTS: ER- and PR-negative patients were statistically significantly more likely to be black, have T2 disease, have tumors detectable on both mammography and physical examination, have grade 3 tumors, and receive chemotherapy. There were no significant differences noted with regard to ER- and PR- patients by HER-2 status. There was a significant difference noted in rates of first distant metastases (3%, 12%, and 7% for Groups 1, 2, and 3, respectively; P = .009). However, the isolated 5-year LRR was not significantly different (2.3%, 4.6%, and 3.2%, respectively; P = .36) between the 3 groups. CONCLUSIONS: Patients with TN breast cancer do not appear to be at a significantly increased risk for isolated LRR at 5 years and therefore remain appropriate candidates for breast conservation. Cancer 2009;115:946-51. (c) 2009 American Cancer Society.