January 30, 2015
Researchers have identified subtypes of stage III colon cancer based on molecular markers associated with differences in clinical and pathological features as well as disease-free survival.
Investigators prospectively collected 2,720 stage III colon cancer samples from participants in an adjuvant chemotherapy trial. They used a polymerase chain reaction-based assay to identify mutations in BRAF (V600E) and KRAS oncogenes, and identified tumors deficient or proficient in DNA mismatch repair (MMR) based on detection of MLH1, MSH2 and MSH6 proteins and MLH1 methylation. Then they characterized tumor subtypes into five groups with respect to clinicopathologic features and rates of disease-free survival (DFS), and validated the findings using separate tumor samples from 783 other patients with stage III cancer.