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.

The International Human Papillomavirus Reference Center: Standardization, collaboration, and quality assurance in HPV research and diagnostics.

The International Human Papillomavirus (HPV) Reference Center (IHRC) confirms and assigns type numbers to novel HPV types, maintains a reference clone repository, and issues international proficiency panels for HPV screening and genotyping. Furthermore, the Center coordinates the Global HPV Reference Laboratory Network that promotes collaboration and international exchange of experiences among national HPV reference laboratories, to further international standardization and quality assurance in the HPV field. The established HPV types (n = 225) belong to 5 different genera: alpha (n = 65), beta (n = 54), gamma (n = 102), mu (n = 3) and nu (n = 1). Since the last published IHRC overview in 2018, 6 novel types have been established, with 5/6 belonging to the gamma genus and 1/6 to beta genus. Also, 474 reference clones have been provided to 55 different research laboratories and the global proficiency program for HPV genotyping has seen an increasing proficiency (despite a decrease seen in 2019), from 68% proficiency in 2017 to 77.3% in 2022. The first proficiency study for HPV screening found an international proficiency of up to 77%. In summary, increasing complexity of the HPVs and demands on quality assurance in the era of cervical cancer elimination requires international efforts to support proficiency and recognized quality and order among HPV types.

Concomitant human papillomavirus (HPV) vaccination and screening for elimination of HPV and cervical cancer.

HPV vaccination with concomitant HPV-based screening of young women has been proposed for faster cervical cancer elimination. We describe the baseline results of a population-based trial of this strategy to reduce the incidence of HPV. All 89,547 women born 1994-1999 and resident in the capital region of Sweden were personally invited to concomitant HPV vaccination and HPV screening with 26,125 women (29.2%) enrolled between 2021-05-03 and 2022-12-31. Baseline HPV genotyping of cervical samples from the study participants finds, compared to pre-vaccination prevalences, a strong decline of HPV16 and 18 in birth cohorts previously offered vaccination, some decline for cross-protected HPV types but no decline for HPV types not targeted by vaccines. Our dynamic transmission modelling predicts that the trial could reduce the incidence of high-risk HPV infections among the 1994-1998 cohorts by 62-64% in 3 years. Baseline results are prevalences of HPV infection, validated transmission model projections, and power estimates for evaluating HPV incidence reductions at follow-up (+/-0.1% with 99.9% confidence). In conclusion, concomitant HPV vaccination and HPV screening appears to be a realistic option for faster cervical cancer elimination. Clinicaltrials.gov identifier: NCT04910802; EudraCT number: 2020-001169-34.