Personalizing Adjuvant Therapy for Stage II/III Colorectal Cancer

This review focuses on three areas of interest with respect to the treatment of stage II and III colon and rectal cancer, including (1) tailoring adjuvant therapy for the geriatric population, (2) the controversy as to the optimal adjuvant therapy strategy for patients with locoregional rectal cancer and for patients with colorectal resectable metastatic disease, and (3) discussion of the microenvironment, molecular profiling, and the future of adjuvant therapy. It has become evident that age is the strongest predictive factor for receipt of adjuvant chemotherapy, duration of treatment, and risk of treatment-related toxicity. Although incorporating adjuvant chemotherapy for patients who have received neoadjuvant chemoradiation and surgery would appear to be a reasonable strategy to improve survivorship as an extrapolation from stage III colon cancer adjuvant trials, attempts at defining the optimal rectal cancer population that would benefit from adjuvant therapy remain elusive. Similarly, the role of adjuvant chemotherapy for patients after resection of metastatic colorectal cancer has not been clearly defined because of very limited data to provide guidance. An understanding of the biologic hallmarks and drivers of metastatic spread as well as the micrometastatic environment is expected to translate into therapeutic strategies tailored to select patients. The identification of actionable targets in mesenchymal tumors is of major interest.