JAMA NetworkAssessment of Long-Term Distant Recurrence-Free Survival Associated with Tamoxifen Therapy in Postmenopausal Patients with Luminal A or Luminal B Breast Cancer

The Stockholm Tamoxifen (STO-3) trial conducted from 1976 to 1990 included 462 postmenopausal patients with lymph node-negative breast cancer. This secondary analysis of trial data (including a 2014 tumor tissue assessment with immunohistochemistry and Agilent microarrays) looked for long-term survival benefit with tamoxifen. The authors conclude that patients with luminal A tumor subtype appeared to have a long-term (i.e., 15-year) benefit from tamoxifen therapy, and patients with luminal B subtype appeared to have an early benefit (i.e., 5 years) from therapy, when the risk of distant metastatic disease was high.