Potential impact of combined high- and low-risk human papillomavirus infection on the progression of cervical intraepithelial neoplasia 2

Abstract

Aim: Few studies have examined the effect of combined low-risk human papillomavirus (LR-HPV) and high-risk human papillomavirus (HR-HPV) infection on the progression of cervical intraepithelial neoplasia (CIN)2 to CIN3. This multi-institutional prospective cohort study investigated the risk of progression of CIN2 with various combinations of HR-HPV and LR-HPV infection.

Methods: Between January 2007 and May 2008, 122 women with CIN2 (aged 20-50 years) from 24 hospitals throughout Japan were enrolled in the study. Ninety-three women were analyzed after a 2-year follow-up with cytology, colposcopy, HR-HPV testing and HPV genotyping. Colposcopy-directed biopsy was performed at entry and the end of this study, or when disease progression was suspected.

Results: Among 93 women with CIN2, 87 (93.5%) had HR-HPV infection. Among these 87 cases, 24 (27.6%) progressed to CIN3 and 49 (56.3%) regressed. None of the six women with CIN2 without HR-HPV infection progressed. The progression rate was significantly lower in women with combined HR-HPV and LR-HPV infection (3/28, 10.7%) than in those with HR-HPV infection only (21/59, 35.6%; P = 0.016). Multivariate analyses showed that CIN2 progression in women with HR-HPV infection was negatively associated with LR-HPV co-infection (hazard ratio = 0.152; 95% confidence interval [CI] = 0.042-0.553). CIN2 regression was positively associated with LR-HPV co-infection (odds ratio = 4.553; 95% CI = 1.378-15.039).

Conclusion: The risk of CIN2 progression is low in women with combined infection of HR-HPV and LR-HPV. The finding may be useful for management of women diagnosed with CIN2.

Keywords: cervical intraepithelial neoplasia; human papillomavirus; infection screening; management of precancer; virus genotyping.