Abstract
BACKGROUND/AIM: Programmed cell death 6 (PDCD6) is up-regulated and highly expressed in early apoptotic cells. In several types of cancer, such as cervical, breast and lung cancers, the association of PDCD6 genotypes have been investigated. However, the contribution of PDCD6 variant genotypes to oral cancer has never been examined. The current study aimed to evaluate the contribution of the PDCD6 rs4957014 and rs3756712 genotypes to the risk of oral cancer in Taiwan. PATIENTS AND METHODS: The contribution of PDCD6 genotypes to oral cancer risk was examined among 958 patients with lung cancer and 958 age- and sex-matched healthy controls by polymerase chain reaction-restriction fragment length polymorphism (PCR- RFLP). RESULTS: The data showed that the hetero-variant GT and homo-variant GG genotypes of PDCD6 rs4957014 were associated with a decreased risk of oral cancer [odds ratio (OR)=0.81 and 0.39, 95% confidence interval (CI)=0.67-0.97 and 0.27-0.56, respectively]. The recessive and dominant models also showed that G carriers have protective effects (OR=0.43 and 0.72, 95% CI=0.30-0.61 and 0.61-0.87, respectively). The analysis of allelic frequency distributions showed that the G allele of PDCD6 rs4957014 was associated with reduced oral cancer risk (OR=0.71, 95% CI=0.62-0.82). There was no significant association between any PDCD6 rs3756712 genotype and oral cancer risk. In addition, the GG genotype at PDCD6 rs4957014 significantly decreased the risk of oral cancer among both males (adjusted OR=0.31, 95%CI=0.24-0.56) and females (adjusted OR=0.44, 95% CI=0.22-0.91). Furthermore, the GG genotype at PDCD6 rs4957014 significantly decreased the risk of oral cancer among smokers (adjusted OR=0.35, 95% CI=0.22-0.58), alcohol drinkers (adjusted OR=0.33, 95% CI=0.18-0.49), non-betel quid chewers (adjusted OR=0.33, 95% CI=0.17- 0.81), betel quid chewers (adjusted OR=0.34, 95% CI=0.21- 0.59), but not among never-smokers and non-alcohol drinkers. CONCLUSION: The G allele carriers of PDCD6 rs4957014 may have protective effects on oral cancer risk and serve as a practical marker for early detection of oral cancer in Taiwan.