There was no correlation between the number of different KRAS mutations and post-surgery cancer staging (R = 0.06, p = 0.65), tumor size according to TNM classification (R = 0.1, p = 0.49), cumulative cigarette consumption expressed as pack-years (R = − 0.02, p = 0.90) or patients’ age (R = − 0.04, p = 0.76). This evidence concerns the gene KRAS and cancer.