The value of PAM50-based Prosigna risk of recurrence (ROR) score for predicting distant recurrence (DR) was examined in a cohort consisting of postmenopausal women with HR+ early breast cancer treated with 5 years of endocrine therapy alone. Prosigna was used to test 2740 patients, and 2558 HR+/HER2− samples were analyzed, including from 1395 node-positive patients. Median follow-up for recurrence was 9.2 years. In all, 26% of the node-positive patients were classified as low ROR (n = 359), with a DR risk of 3.5% versus a DR risk of 22.1% at 10 years for patients classified as high ROR (n = 648). Node-negative patients classified as low and high ROR had a risk of DR of 5.0% and 17.8%, respectively. Women with luminal B tumors (n = 947; DR risk, 18.4%) had a significantly worse outcome than those with luminal A tumors (n = 1474; DR risk, 7.6%; P < .001).
Prosigna ROR score improved the prediction of outcome. In a real-world setting, Prosigna can reliably identify node-negative patients and a significant proportion of patients with one to three positive nodes who can be spared treatment with adjuvant chemotherapy.
