Subjects with MAOA rs1137070 (T-allele) and MAOB rs6324 (G-allele) had a significantly increased risk of oral and pharyngeal cancers (AOR = 45.56; 95% CI, 18.51–112.17) and risk of OPMD (AOR = 70.59; 95% CI, 14.17–351.78). This evidence concerns the gene MAOB and pharynx cancer.