A new study has reported that patients with triple negative breast cancer who do not undergo radiation treatment have a significantly higher risk of locoregional recurrence (recurrence in the breast, chest wall, or lymph nodes) than those who do, even among women with early stage disease. Triple negative breast cancer is estrogen receptor negative (ER-), progesterone receptor negative (PR-), and does not overexpress human epidermal growth factor receptor 2 (HER2/neu-).

The study included 77 triple negative breast cancer patients for whom data collection began in 2004. Study participants had all phases of their breast cancer treatment (surgery, chemotherapy, and radiation) at one institution, with a median follow-up period of almost two years. Women with all types of surgery (lumpectomy/mastectomy), chemotherapy (neoadjuvant/adjuvant), and radiation treatment (tangents only/comprehensive nodal irradiation) were included in the study. A patient was given radiation treatment if she underwent a lumpectomy or after mastectomy if the primary tumor was at least 5 cm in size and/or four or more positive lymph nodes were found.

Patients who received radiation treatment were more likely to have higher stage tumors than those who did not receive radiotherapy. For the entire study group, one-year overall survival was 90.9% and three-year overall survival was 86.3%. The three-year probability of locoregional relapse-free survival for patients who received radiation (79.6%) was higher than for those who did not receive radiation (57.9%). The authors conclude that, despite significantly lower tumor stage, patients with triple-negative breast cancer who do not undergo radiation treatment have a significantly higher risk of locoregional recurrence.