A Multigene Assay to Predict Recurrence of Tamoxifen-Treated, Node-Negative Breast Cancer

A polymerase-chain-reaction assay of 21 genes performed on paraffin-embedded samples from women with node-negative, estrogen-receptor–positive breast cancer was the basis for calculating a score for the risk of distant recurrence. The difference in risk between women with low and high recurrence scores was significant. The recurrence score also predicted overall survival. An assay of 21 genes was the basis for calculating the risk of distant recurrence. The difference in risk between women with low and high recurrence scores was significant. Over the past two decades, the molecular dissection of cancer has increased our understanding of the pathways that are altered in neoplastic cells. 1 , 2 Nevertheless, the diagnosis of cancer and decisions about its treatment still rely largely on classic histopathological and immunohistochemical techniques. A more quantitative approach to diagnosis and rational individualization of treatment are needed. Large clinical trials, such as National Surgical Adjuvant Breast and Bowel Project (NSABP) trials B-14 and B-20, have demonstrated the benefit of tamoxifen and chemotherapy in women who have node-negative, estrogen-receptor–positive breast cancer. 3 – 5 However, since the likelihood of distant recurrence in patients treated . . .