Nationwide registry-based trial of risk-stratified cervical screening.

In well-screened populations, most cervical cancers arise from small groups of women with inadequate screening. The present study aims to assess whether registry-based cancer risk assessment could be used to increase screening intensity among high-risk women. The National Cervical Screening Registry identified the 28,689 women residents in Sweden who had either no previous cervical screening or a screening history indicating high risk. We invited these women by SMS and/or physical letter to order a free human papillomavirus (HPV) self-sampling kit. The Swedish national HPV reference laboratory performed extended HPV genotyping and referred high-risk HPV-positive women to their regional gynecologist. A total of 3691/28,689 (12.9%) women ordered a self-sampling kit and 10.0% (2853/28,689) returned a sample for testing. Participation among women who had never attended screening was low, albeit improved. Up to 22.5% of women in other high-risk groups attended. High-risk HPV types were detected in 8.3% of samples. High-risk HPV-positive women (238/2853) were referred without further triaging and severe cervical precancer or cancer (HSIL+) in histopathology were detected in 36/158 (23%) of biopsied women. Repeat invitations gave modest additional participation. Nationwide contacting of women with high risk for cervical cancer with personal invitations to order HPV self-sampling kits resulted in high yield of detected CIN2+. Further efforts to improve risk-stratified screening strategies should be directed to improving (i) the precision of the risk-stratification algorithm, (ii) the convenience for the women to participate and, (iii) ensuring that screen-positive women are followed-up.