Adjuvant chemotherapy can improve survival in patients with early-stage breast cancer or colorectal cancer who have undergone surgical resection, but the benefit from this treatment is not universal. A distinguished panel of experts addresses the advance in molecular diagnostic testing and its impact on optimal care for cancer patients. David M. Hyams, MD, FACS, presents the epidemiology of breast and colorectal cancers and discusses treatment options and how molecular diagnostics can be used to better manage patients. Cari Bruins, PharmD, focuses on the impact of molecular diagnostics on health outcomes and cost in quality-of-care initiatives. Winston Wong, PharmD, shows the value of incorporating genomic testing into oncology treatment pathways.