Randomized Implementation of Primary Human Papillomavirus (HPV) Testing in the Organized Screening for Cervical Cancer in Stockholm

Primary HPV screening is a method with higher sensitivity than cytology for detection of high-grade cervical intraepithelial neoplasia, which is the precursor of cervical cancer. In particular, HPV test is a better test for revealing adenocarcinomas, since these cancers often show a normal cytology.

Cytology is less effective in older women, and screening with cytology in women over 60 has no documented effect. Today a large part of cervical cancer develop in women older than 60, to whom no screening is offered. The prevalence of HPV is around 4% in this age group. Since we know that testing negative for HPV gives a better long-term protection against cervical cancer compared to cytology, primary screening for HPV in 60-year old women would give a longer lasting protection in this high-risk group compared with today.

HPV screening is most cost effective above 35 years of age. The reason for this is that HPV is less prevalent at age 35 than in younger women and also because cervical cancer seldom develops before this age. Since the HPV test has a negative predictive value (NPV) of almost 100% this could lead to longer screening intervals, which would be improve cost-effectiveness.