Application of microsatellite instability and oncotype DX in stage II colon cancer adjuvant chemotherapy

Adjuvant chemotherapy has improved the overall prognosis for patients with stage IIIcolon cancer. However, the precise role of adjuvant chemotherapy for patients with stage II colon cancer remains a matter of ongoing debate. While patients with high-risk stage II disease derive clinical benefit from adjuvant therapy, it remains unclear as to whetherpatients with average or low-risk stage II disease should receive further therapy following surgical resection. Significant efforts have focused on developing and validating molecular biomarkers to further define the subset of patients with stage II disease who would derive benefit from adjuvant therapy. Herein, we review the current status of biomarker research with respect to the specific roles of microsatellite instability and genotype analysis in patients with stage II colon cancer.