Infection by human papillomavirus types 6, 11, 16, 18, 31, 33 and 35 of the cervix in Japanese women.

Exfoliated cervical cells from 321 Japanese women were examined for human papillomavirus (HPV) DNA types 6, 11, 16, 18, 31, 33 and 35 using polymerase chain reaction (PCR) and dot-blot hybridization methods. HPV DNA was present in 9.3% of patients with normal cervixes, 72.7% of patients with cervical intraepithelial neoplasia (CIN) and 77.8% of patients with invasive carcinoma. Younger patients (29 years) with normal cervixes had a 18.5% incidence of HPV DNA, whilst similar older patients (50 years) had a 1.9% incidence, a significant difference (χ²= 6.478, P < 0.01). In the CIN I and II groups, an incidence of 11.1% of types 16 and 18 was found, while in the CIN III or invasive carcinoma group the incidence was 58.1%, again a significant difference (χ² = 12.075, P < 0.01). Furthermore, persistence or progression of CIN showed a significant correlation with infections by types 16 and 33 (χ²= 4.904, P < 0.01). However, no significantly different incidence of HPV infection was found between the CIN and the invasive carcinoma groups. It is suggested that (a) younger patients with normal cervixes have a higher incidence of HPV infection than do older patients; (b) HPV types 16, 18 and 33 are important etiologic agents of CIN III and invasive carcinoma, as well as in the persistence and progression of CIN; (c) progression of CIN to invasive carcinoma may depend on factors other than HPV infection in the cervix. [ABSTRACT FROM AUTHOR]