Clinical and Genomic Risk in Adjuvant Therapy for Breast Cancer. Reply.

Abstract

To the Editor: Sparano et al. (June 20 issue)1 report prognostic and predictive implications by integrating clinical-risk stratification with a 21gene assay to guide adjuvant therapy in patients with hormone-receptor–positive breast cancer who also have negative results on testing for human epidermal growth factor receptor 2 (HER2) and for metastasis to the axillary lymph nodes. The vast majority of patients with low clinical risk did not benefit from chemotherapy on the basis of their genomic recurrence score in TAILORx (Trial Assigning Individualized Options for Treatment). With the exception of patients who were 50 years of age or younger, who may still benefit from chemotherapy if they have a recurrence score of 21 to 25, all the other women with low clinical risk did not have proven benefit. Among the 6615 patients at low clinical risk, only 589 (9%) had a recurrence score of more than 25 and received adjuvant chemotherapy, although the actual benefit remains unknown. In the MINDACT trial, a similar group of patients did not have improvement with chemotherapy.2 Thus, we can postulate that a gene assay may not even be necessary to guide the decision for all patients who are older than 50 years and are at low clinical risk, given its high costs and lack of proven costeffectiveness so far, particularly in developing countries.3 Starting from a clinical-risk stratification, we could spare 47% of all patients and 77% of those at low clinical risk from taking the genomic test.