In stage III colon cancer, adjuvant therapy became widely adopted as evidence of the efficacy of 5-fluorouracil–based adjuvant regimens began to accumulate in the 1990s.3,4,5 Adjuvant treatment with either endocrine therapy, anti-ERBB2 (formerly HER2/neu)–directed therapy, or chemotherapy is currently recommended for many patients with early-stage breast cancer on the basis of numerous randomized controlled trials and subsequent meta-analyses.6 This evidence concerns the gene ERBB2 and breast cancer.