Evaluation of new and current preventive strategies for cervical and vaginal cancer

This thesis addresses clinical research questions on primary and secondary prevention of cervical and vaginal cancer by targeting four groups of women in the organized cervical screening program; women entering the screening program, women exiting the screening program, non-attenders in the screening program, and women previously treated for precancerous lesions. In Study 1, we evaluated the colposcopic and histopathologic findings in women with 1 and 3 year human papillomavirus (HPV) persistence, respectively, in women exiting the cervical screening program at age 56-64. The design was a randomized health care policy offering HPV screening to 50% of resident women exiting the screening program in the Stockholm-Gotland region of Sweden during January 2012 through May 2014. Women with HPV persistence were referred to colposcopy. Biopsies as well as an endocervical sample analyzed for cytology and HPV was taken at the examination. HPV was analyzed for 14 different possibly oncogenic genotypes. We found that HPV prevalence was 5.5% (405 women of 7325 attending). After one year, 91 of 176 (52%) were persistently HPV positive and after three years 55 of 137 (40%) (p=0.042). Histopathologically confirmed cervical intraepithelial lesions grade 2 or worse (CIN2+) was found in 19 of 82 women (23%) and 9 of 45 women (20%) in the 1 and 3 year groups, respectively, indicating that it was safe to postpone repeat HPV testing for three years in women exiting the cervical screening program. There was a high risk for CIN2+ at follow-up and noteworthy yields from HPV genotyping as well as endocervical sampling and random biopsies in the absence of visible colposcopic lesions. In Study 2, we compared the colposcopic evaluation in vaccinated and unvaccinated women entering the organized cervical screening program. Women in the 1994 and 1995 birth cohorts who entered the cervical screening program at age 23 in one region in Sweden were identified. Colposcopy was performed within two to four months after a positive screening result ...