[A 1:2 matched case-control study on the interaction of HPV16E6 and HLA-DR9 allele to esophageal cancer in Kazakh ethnicity, Xinjiang].

OBJECTIVE

To evaluate the role and the association between HPV16E6 infection and HLA-DR9 immune-associated gene to esophageal cancer (EC) in Kazakh of Xinjiang, China.

METHODS

A 1:2 matched case-control study was conducted with 63 cases of EC and 126 controls involved. The controls were matched by sex, nationality, area of residence and age within 5-year difference. HPV16E6 and HLA-DR9 allele were identified by PCR-SSP. Interaction was performed to identify risk factors.

RESULTS

HPV16E6 infection and HLA-DR9 allele positive status were the risk factors for EC, with OR values as 2.67 (95%CI: 1.38 - 5.17) and 3.83 (95%CI: 1.48 - 9.96) respectively. The rate of HPV16E6 infection in individuals with HLA-DR9 allele was different from the ones who were HLA-DR9 allele free (chi(2) = 7.57, P = 0.006), with OR value as 5.79 (95%CI: 1.53 - 21.87). In the controls, the rates of HPV16E6 infection were 22.2% and 16.2% among individuals with HLA-DR9 allele atatus as positive or negative, and without statistically significant difference. Interaction analysis showed there was an interaction of HPV16E6 with HLA-DR9 and were higher than the sum of the two factors presented individually.

CONCLUSION

In our study, we found that the HLA-DR9 allele and HPV16E6 infection had a function of synergy in the process of malignant transformation of esophageal epithelial cells, and jointly promoting the occurrence and development of EC.