New approach to HPV self-diagnosis may improve cervical cancer screening

Analyzing the results of self-testing for human papillomavirus (HPV) can be used to divide HPV-positive women into three risk groups, according to a new study from the Karolinska Institute and Queen Mary University of London published in the journal PLOS Medicine. The method could be important for improving cervical cancer screening.

The study is based on women in the UK who were asked to self-test for HPV because they had not been screened for cervical cancer in time.

“HPV self-testing has become an important component of cervical screening. It reaches women who would not otherwise participate,” said Jiayao Lei, associate professor of medical epidemiology and biostatistics and chair of the Department of Clinical Sciences, Interventions and Technology and lead author of the study.

The study, conducted in primary care centers in England, enrolled 855 women with a positive HPV self-diagnosis, that is, indicating HPV infection, and subsequent sample collection and analysis by a physician. Of these women, 71 (8.3%) were found to have severe pre-cancer or cervical cancer.

Further investigation for the high-risk group

Researchers examined detailed information about HPV test results in a self-collected sample and used a new method to assess the risk of serious cellular changes. Risk stratification was based on the type of HPV virus and the amount of virus (Ct) present in the self-collected sample. Based on this, they categorized women into three risk groups: high, medium, and low risk. Women with HPV type 16 and a low Ct value (<30) had the highest risk of developing severe precancer or cervical cancer.

Approximately 40% of the high-risk women were diagnosed with severe precancer or cervical cancer requiring treatment. Therefore, in the future, the researchers recommended that this group be referred for further screening with colposcopy.

More than half of those who tested positive were in the low-risk group, where women in this group had a 4% chance of being diagnosed with severe precancer or cervical cancer within 12 months.

“We believe that the low-risk group can be retested after 12 months and the moderate-risk group should be referred to their doctors for further analysis,” said senior study author Peter Sasieni, a professor at Queen Mary University of London.

Benefits of risk stratification

One of the main advantages of the new method is that risk assessment can be performed directly after HPV self-testing, without the need for additional laboratory tests.

This may be particularly useful for cervical cancer screening in low- and middle-income countries where resources are limited.

Next steps in the research

With support from the Swedish Cancer Society, the researchers will conduct a large-scale population-based, self-testing study in Sweden using a different test to test the feasibility of incorporating such risk stratification into standard screening programs. They also plan to investigate the prognostic value of the current test results in combination with other markers for HPV-positive women.