Spontaneous evolution of human papillomavirus infection in the uterine cervix

Background: Little is known about the natural history and the malignant pot ential of low-grade cervical intraepithelial neoplasia associated with huma n papillomavirus (HPV) infection. Cervical cancer remains the second most f requent cause of death in women across the world. Epidemiologic and molecul ar studies have shown that human papillomavirus (HPV) is associated with ce rvical carcinogenesis. In this prospective study we examined the behavior o f low-grade cervical intraepithelial lesions associated with HPV infection over a 6-year period. Material and Methods: During 1992, women with Papanic olaou smears reporting koilocytotic atypia (HPV effect) with or without gra de 1 cervical intraepithelial neoplasia (HPV+/-CINI, low grade squamous int raepithelial lesions, LgSIL), along with colposcopic impression of LgSIL we re included to the study. Between 1992 and 1998 all women underwent repeat Papanicolaou smears, colposcopic evaluation and HPV DNA testing every six m onths. HPV typing of cervical scrapes was done by PCR. Results A total of 3 30 women completed at least 6 years of follow-up. Among women with high-ris k HPV types (16/18), the presence of dysplasia (grade 1 cervical intraepith elial neoplasia) was significantly correlated with the progression of the l esion; 29% of cases with HPV+CINI (15 out of 75) progressed to more severe lesions versus only 9% of cases with HPV infection (18 out of 225), P<0.001 , chi-square test. The incidence of histologically confirmed progressive le sions was significantly greater in women with mild dysplasia (18 out of 75, 24%) compared to women without dysplasia (13 out of 255, 5%), P<0.001, chi -square test. Conclusions: In our study HPV typing was not predictive of th e evolution of low-grade intraepithelial lesions associated with HPV infect ion. Standard cytologic screening and colposcopy are the most effective mea ns of monitoring low-grade lesions.