Based on the use of a 70-gene signature test (MammaPrint) to guide treatment decisions, a recent randomized clinical trial published in the New England Journal of Medicine found nearly half of women with early-stage breast cancer who are at high clinical risk of recurrence might not require chemotherapy to achieve favorable survival outcomes. The findings suggest that the biologic characteristics of a tumor are as important to outcomes as tumor burden.
Slomski A. Tumor Gene Testing May Help Guide Breast Cancer Treatment Decisions. JAMA. 2016;316(16):1637. doi:10.1001/jama.2016.14764