The standard adjuvant therapy for resected stage III colon cancer has been intravenous 5-fluorouracil. However, newer chemotherapy agents, such as capecitabine, oxaliplatin and irinotecan, have been investigated in clinical trials since the publication of the original guidelines. The Gastrointestinal Cancer Disease Site Group (DSG) conducted a systematic review of the evidence for the use of adjuvant systemic chemotherapy for patients with resected stage II and III colon cancer and developed an updated practice guideline based on that evidence and expert consensus. The following research questions were addressed: Should patients with stage II or III colon cancer receive adjuvant systemic chemotherapy? What are the preferred adjuvant systemic chemotherapy options for patients with completely resected stage II or III colon cancer? Outcomes of interest were disease-free survival, overall survival, adverse effects and quality of life.
A systematic search of published studies was conducted for the time period following the publication of the original guidelines to identify relevant randomised trials and syntheses of evidence in the form of meta-analyses. Recommendations were based on that evidence, evidence contained in the original guidelines and consensus of the Gastrointestinal Cancer DSG. The systematic review and practice guideline were externally reviewed through a mailed survey of practitioners in Ontario, Canada.
Recommendations were drafted based on the available evidence and expert consensus.
The routine use of adjuvant chemotherapy for all patients with stage II colon cancer is not recommended. However, a subset of patients with high-risk stage II disease should be considered for adjuvant therapy. Patients with completely resected stage III colon cancer should be offered adjuvant chemotherapy. Treatment should depend on factors such as patient suitability and preference, and patients and clinicians must work together to determine the optimal course of treatment.