Chemotherapy for Stage II Colon Cancer

The adjuvant treatment of patients with stage II colon cancer is an area of controversy in medical oncology. Adjuvant chemotherapy aims to eradicate micrometastatic disease present at the time of surgery, preventing the development of distant metastatic disease and thereby curing those patients of their cancer. National and international guidelines for the adjuvant treatment of stage II colon cancer recommend a range of treatment options from observation to chemotherapy with single-agent or combination regimens, depending on the presence or absence of high-risk features (poorly differentiated histology, presence of lymphovascular invasion, presence of perineural invasion, report of < 12 lymph nodes, bowel obstruction, localized perforation, or positive margins). In the one prospective study designed to address the role of adjuvant chemotherapy in stage II colon cancer, a small but statistically significant benefit in overall survival was seen for those patients who received adjuvant chemotherapy; however, multiple meta-analyses and retrospective subgroup analyses have called these findings into question. Though there may be a role for adjuvant chemotherapy in the treatment of patients with stage II colon cancer, its incremental benefit is small, at best, and comes with the risks of real and rarely fatal complications of chemotherapy.