KRAS and neoplasm: Statistical analysis indicated that KRAS mutation was significantly higher in the deeper invasion stage (5/7[71.4%] in T4 vs 10/48[20.8%] in T3; OR 9.500, 95% CI 1.599–56.426; P = 0.013), and tumor with poor differentiation showed a higher NRAS mutation rate than moderate differentiation (5/19[26.3%] vs 1/30[3.3%]; OR 10.357, 95% CI 1.103–97.266; P = 0.027).