The prognostic value of Microsatellite Instability, KRAS, BRAF and PIK3CA mutations in stage II colon cancer patients.

In the era of personalized cancer medicine, identifying mutations within patient tumors plays an important role in defining high risk stage II colon cancer patients. The prognostic role of BRAF V600E mutation, MSI status, KRAS mutation and PIK3CA mutation in stage II colon cancer patients is not just settled.,We retrospectively analyzed 186 patients with stage II colon cancer who underwent an oncological resection but were not treated with adjuvant chemotherapy. KRAS mutations, PIK3CA mutation, V600E BRAF mutation and MSI status were determined. Survival analyses were performed.,Mutations were found in respectively 23% (MSI), 35% (KRAS), 19% (BRAF) and 11% (PIK3CA) of the patients. A trend towards worse overall survival (OS) was seen in patients with a MSI (5-year OS 74% vs. 82%, adjusted HR 1.8, 95% CI 0.6-4.9) and a KRAS mutated tumor (5-year OS 77% vs. 82%, adjusted HR 1.7, 95% CI 0.8-3.5). MSI and BRAF mutated tumors tended to correlated with poorer disease-free survival (DFS) (5-year DFS 60% vs. 78%, adjusted HR 1.6, 95% CI 0.5-2.1 and 5-year DFS 57% vs. 77%, adjusted HR 1.1, 95% CI 0.4-2.6 respectively).,In stage II colon cancer patients not treated with adjuvant chemotherapy, BRAF mutation and MSI status both tended to have a negative prognostic effect on disease-free survival. KRAS and MSI status also tended to be correlated with worse overall survival.