Detection and typing of human papillomavirus in cervical intraepithelial neoplasia grade III in Thai women.

Infection of human papillomaviruses (HPVs) has been shown to play an important role in the development of cervical cancer from precancerous lesions known as cervical intraepithelial neoplasia (CIN-I, CIN-II and CIN-III). In Thailand, cervical cancer is the most common cancer in women. Fifty tissue samples diagnosed as CIN-III and 50 tissues of normal histopathologic appearance as controls were examined for the presence of HPV-DNA and HPV typing using PCR and dot hybridization (DH) methods. All specimens used in this study were formalin-fixed paraffin embedded tissues. HPV-DNA was detected in 74% (37/50) of CIN-III and 6% (3/50) of the control group giving a crude odd ratio of 44.58 (95% confidence interval of 15.2-130). Among the CIN-III group, the most prevalent type was HPV-16; 48.65% (18/37) followed by HPV-18; 16.2% (6/37) and HPV-33; 10.8% (4/37). Mixed infection was identified in 4 specimens, ie HPV-6/16, HPV-16/18, HPV-16/33, and HPV-16/18/33. Twelve samples were untyped. In the control group, only one sample (33.3%) was detected to contain HPV-6 DNA and the remaining ones were untyped. Our results revealed infection with HPV, especially HPV-16 and HPV-18, to be strongly associated with CIN-III in Thai women.