KRAS and alcohol drinking: The Kaplan–Meier method, used to evaluate the mean survival time and survival rate of patients, showed a significant decrease of these parameters for EGFR, cyclin D1, and KRAS high-expressing groups, influencing prognosis as well as age, smoking, and alcoholism, that were considered relative risk factors by multivariate analysis of prognosis using the Cox regression model, while clinical stage and response to treatment were independent risk factors [49].