New test detects more cases of cervical cancer

Cervical cancer screening is essential for early detection and prevention. Most countries have a very extensive screening program that starts with testing for different variants of the human papillomavirus (HPV) that causes cervical cancer. In the case of an HPV-positive test, this is followed by so-called cytological analysis, the examination of gynaecological cell samples by microscopy, which is dependent on human interpretation.

The new molecular test WID-qCIN, which could replace the cytological analysis, can automatically analyse epigenetic changes in cells, i.e. changes that affect which genes are active and which are not. These changes are influenced by factors such as environment, lifestyle, and aging, and can increase the risk of cancer and other diseases.

The current study included more than 28,000 women over the age of 30 who underwent screening in Stockholm between January and March 2017. The researchers analysed a total of 2,377 HPV-positive samples with the WID-qCIN test combined with a test for two high-risk HPV types (HPV 16 and 18). In this way, they were able to detect 100 per cent of all invasive cervical cancer and 93 per cent of all serious precancerous lesions that occurred within a year of sampling.

In addition, the new test, in combination with the HPV 16/18 test, was able to predict 69 per cent of all cancers and precancerous lesions up to six years after the sample was taken. This can be compared with only 18 per cent with today's screening method.

"By integrating the WID-qCIN test into our screening programs, we would be able to identify more cancer cases while reducing the need for invasive procedures," says Joakim Dillner, Professor of Infectious Disease Epidemiology at the Department of Clinical Science, Intervention and Technology, Karolinska Institutet and co-author of the study.

When cell changes are detected in today's screening program, the woman undergoes a vaginal examination, a so-called colposcopy, where the gynaecologist looks at the cervix with the help of a microscope and, if necessary, takes a biopsy. The biopsy involves a surgical procedure that, among other things, can lead to negative pregnancy outcomes like premature delivery. The results of the current study suggest that implementation of the WID-qCIN test could reduce the number of colposcopy examinations by 40 per cent.

"This would mean a significant improvement compared to today's screening methods, which were introduced in the 1960s," says the study's last author Martin Widschwendter, Professor at the University of Innsbruck and visiting Professor at the Department of Women's and Children's Health, Karolinska Institutet. "With its simplicity and objective assessment, the WID-qCIN test can improve the effectiveness of these programs and support the global strategy to eliminate cervical cancer."

The study was funded by the federal state of Tyrol and the EU's research and innovation programme Horizon 2020. Several of the authors are inventors of patents related to the WID-qCIN test and are shareholders in Sola Diagnostics GmbH, which holds the rights to commercialise the test. Co-author Karin Sundström has received consulting fees and research grants from Merck Sharp & Dohme for studies on HPV vaccination in Sweden.