Distribution of human papillomavirus type 16 E6 and E7 gene variants in the progression of cervical dysplasia in Korean women

AIM: This cross-sectional, hospital-based study examined the distribution of human papillomavirus 16 E6 and E7 gene variants in Korean women with cervical lesions of varying degrees. MATERIAL & METHODS: One hundred and forty-one Korean women (median age 43 years; range 22-65 years) with human papillomavirus 16 single infections were included. The human papillomavirus 16 E6/E7 sequences were amplified from cytology specimens. The distribution of human papillomavirus 16 variations with respect to cervical lesion was examined by the exact Mantel-Haenszel linear trend test (P(trend) ) and Fisher's exact test (P). RESULTS: Human papillomavirus 16 E6 and E7 gene variants were identified in a total of 100 women (70.9%). The most prevalent human papillomavirus 16 variants were E6 Thymine178Guanine (number = 70, 49.6%) and E7 Adenine647Guanine (number = 75, 53.2%). Human papillomavirus 16 E6 Thymine178Guanine and E7 Adenine647Guanine were significantly related to the degree of cervical neoplasia (P(trend) = 0.0002, P< 0.0001; P(trend) < 0.0001, P < 0.0001, respectively). The odds ratio of human papillomavirus 16 E6 Thymine178Guanine to predict progression to cervical intraepithelial neoplasia 2-3 and invasive cancer was 2.37 (95% confidence interval 1.03-5.45) and 9.07 (95% confidence interval 2.86-28.72), respectively. The odds ratio of E7 Adenine647Guanine to predict progression to cervical intraepithelial neoplasia 2-3 and invasive cancer was 3.65 (95% confidence interval 1.16-8.51) and 9.07 (95% confidence interval 2.86-28.72), respectively. CONCLUSION: The distribution of HPV variants appears to be related to geographic difference. Human papillomavirus 16 E6 Thymine178Guanine and E7 Adenine647Guanine can be used as the candidate marker for the progression of the cervical neoplasia.