To study results of radiation on the local control of triple receptor negative breast cancer (negative estrogen (ER), progesterone (PR) and HER-2/neu receptors).
Materials and Methods
Conservative surgery and radiation were used in 753 patients with T1–T2 breast cancer. Three groups were defined by receptor status: ER or PR (+) group 1; ER and PR (−) but HER-2 (+) group 2; and triple negative (TN) group 3. Factors analyzed were age, menopause, race, stage, tumor size, node status, presentation, grade, extensive in-situ disease, margins, and systemic therapy. The primary endpoint was 5-year local-regional recurrence (LRR) isolated or total with distant metastases.
ER and PR negative patients were statistically significantly more likely to be black, T2, have tumors detectable on both mammogram and physical exam, grade 3, and receive chemotherapy. There were no significant differences in ER and PR negative patients by Her-2 status. There was a significant difference in rates of first distant metastases (3%, 12% and 7% for groups 1, 2 and 3, respectively, p=0.009). However, the isolated 5-year LRR was not significantly different (2.3%, 4.6%, and 3.2%, respectively, p=0.36) between the 3 groups..
Patients with TN breast cancer are not at significantly increased risk for isolated LRR at 5-years so remain appropriate candidates for breast conservation.