Even after the adjustment for risk factors, the MACC1 SNP rs4721888 disclosed a significantly statistical result, the GC genotype (p = 0.044, AOR = 1.466, 95% CI = 1.045–2.057) and C-allele (GC + CC) (p = 0.020, AOR = 1.466, 95% CI = 1.062–2.024) showed a significant association with the incidence of oral cancers in people who were used to chewing betel quid. The gene discussed is MACC1; the disease is lip and oral cavity carcinoma.