Incidence risk of cervical intraepithelial neoplasia 3 or more severe lesions is a function of human papillomavirus genotypes and severity of cytological and histological abnormalities in adult Japanese women.

We examined incidence probabilities of cervical intraepithelial neoplasia 3 (CIN3) or more severe lesions (CIN3+) in 1,467 adult Japanese women with abnormal cytology in relation to seven common human papillomavirus (HPV) infections (16/18/31/33/35/52/58) between April 2000 and March 2008. Sixty-seven patients with multiple HPV infection were excluded from the risk factor analysis. Incidence of CIN3+ in 1,400 patients including 68 with ASCUS, 969 with low grade squamous intraepithelial lesion (LSIL), 132 with HSIL without histology-proven CIN2 (HSIL/CIN2(-)) and 231 with HSIL with histology-proven CIN2 (HSIL/CIN2(+)) was investigated. In both high grade squamous intraepithelial lesion (HSIL)/CIN2(-) and HSIL/CIN2(+), HPV16/18/33 was associated with a significantly earlier and higher incidence of CIN3+ than HPV31/35/52/58 (p = 0.049 and p = 0.0060, respectively). This association was also observed in LSIL (p = 0.0002). The 1-year cumulative incidence rate (CIR) of CIN3+ in HSIL/CIN2(-) and HSIL/CIN2(+) according to HPV genotypes (16/18/33 vs. 31/35/52/58) were 27.1% vs. 7.5% and 46.6% vs. 19.2%, respectively. In contrast, progression of HSIL/CIN2(+) to CIN3+ was infrequent when HPV DNA was undetected: 0% of 1-year CIR and 8.1% of 5-year CIR. All cervical cancer occurred in HSIL cases of seven high-risk HPVs (11/198) but not in cases of other HPV or undetectable/negative-HPV (0/165) (p = 0.0013). In conclusion, incidence of CIN3+ depends on HPV genotypes, severity of cytological abnormalities and histology of CIN2. HSIL/CIN2(+) associated with HPV16/18/33 may justify early therapeutic intervention, while HSIL/CIN2(-) harboring these HPV genotypes needs close observation to detect incidence of CIN3+. A therapeutic intervention is not indicated for CIN2 without HPV DNA.