Influence of KRAS mutations on outcome in patients with curatively resected stage III colon cancer treated with adjuvant chemotherapy.

e14536 Background: Adjuvant chemotherapy improves survival in patients with stage III colon cancer (CC) after curative resection, and oxaliplatin in combination with fluoropyrimidine-based regimens has been established as a standard treatment. KRAS mutations could predict oxaliplatin sensitivity in CC cells, as recently demonstrated. Here, we profiled KRAS and correlated it with outcome in stage III CC patients who underwent adjuvant chemotherapy. Methods: Eligible patients were those with resected stage III CC who underwent 6-months adjuvant chemotherapy, either with single-agent fluoropyrimidine (FP: modulated 5FU or capecitabine) or with oxaliplatin-based regimens (O-FP: FOLFOX or XELOX). DNA extraction was performed on formalin-fixed paraffin-embedded sections, and KRAS mutations were analyzed by direct sequencing. Disease-free survival (DFS) and overall survival (OS) analyses were computed using the Kaplan-Meier method and the Log-rank test. Results: The study population included 261 patients: 115 tr...