Adjuvant treatment of colon cancer: what is next?

Since 2003, fluorouracil/leucovorin plus oxaliplatin (FOLFOX) has been the standard of care in adjuvant therapy. This review reports the results of recent phase III trials which have attempted to improve upon the existing standard of care in adjuvant therapy. In addition, we examine how results of these trials have shaped our knowledge and outline directions for future research.

The demonstrated efficacy of adding irinotecan, bevacizumab, or cetuximab to fluorouracil-based regimens in the treatment of patients with metastatic colorectal cancer led to several multicenter phase III trials investigating the efficacy of these agents in the adjuvant setting. In the last 2 years, all of these trials have reported failures to improve patient outcomes, and the field has remained essentially static.

Negative results from multiple phase III trials suggest that the existing paradigm for the selection of agents to use in adjuvant trials is deeply flawed. Moving forward, we need to ensure mechanistic rationale for clinical trial design and reassess whether disease-free survival is the primary endpoint that should be used to evaluate biologic agents. Future research should be directed toward the development of prognostic and predictive markers for the development of a data-driven roadmap to inform risk stratification and therapeutic decision-making.