The study of the degree of tumor infiltration based on the tumor staging guidelines from “AJCC Staging Manual” [32] showed statistical differences between the risk of presenting loss of MMR protein expression between patients with tumors that do not infiltrate the lamina propria (pTa) and those patients with tumors that infiltrate the lamina propria (pT1), with an OR of 9.857 (95% CI: 1.253–77.575; p = 0.006). This evidence concerns the gene MRC1 and neoplasm.