KRAS and carcinoma: In case of carcinomas located in the distal colorectal segments, the factors that achieved independent statistical significance were MLH1 positivity (OR = 1.95, 95%CI, p = 0.042), absence of BRAF mutation (OR = 0.32, 95%CI, p = 0.0037), K-ras mutation (OR = 1.67, 95%CI, p = 0.025) and MSS (OR = 0.37, 95%CI, p = 0.0046).