Researchers seek new approaches to HPV screening and early cancer risk detection

A study led by Adjunct Professor Ville N. Pimenoff at the University of Oulu is investigating how the prevalence of papillomaviruses in the Finnish population has changed over more than 16 years following vaccination. It is essential to examine the role of the remaining papillomaviruses in cancer development when vaccination has effectively eliminated the most common cancer-causing types from the population. The reduction in highly aggressive cancer-causing viruses has a significant impact on how HPV infections should be screened in the near future.

Cervical cancer declining

In Finland, the incidence of cervical cancer has decreased over the long term thanks to effective screening and vaccination. In particular, severe precancerous lesions have already declined in vaccinated younger age groups.

At the same time, researchers emphasise that not all cancer-causing HPV types have disappeared. Vaccinations target specific high-risk papillomaviruses, but other virus types continue to circulate in the population.

Pimenoff’s research group is examining which papillomavirus types remain risk factors for cancer in the vaccinated population and how cervical cancer screening should be updated as vaccinated cohorts reach screening age.

“It is still unclear how the spectrum of less aggressive papillomaviruses will settle in the vaccinated population once the most aggressive cancer-causing virus types have been eliminated,” Pimenoff explains.

Oropharyngeal cancers have increased particularly among men

Unlike cervical cancer, HPV-related oropharyngeal cancers have increased in recent decades in many Western countries, including Finland. The rise has been particularly pronounced among men.

The increase is thought to be linked to changes in sexual behaviour and the spread of HPV infections in the population before widespread vaccination coverage. As current middle-aged and older cohorts have not received the HPV vaccine, their risk of developing oropharyngeal cancer remains.

Pimenoff’s research group is investigating biological markers in blood and saliva that could enable the risk of oropharyngeal cancer to be identified years before the disease develops. The research is being conducted in collaboration with researchers at the university hospitals of Oulu, Tampere and Helsinki, as well as the Heidelberg Cancer Institute.

“A screening method that could identify individuals at increased cancer risk years before a potential diagnosis would be a highly effective way to prevent oropharyngeal cancer in the unvaccinated population,” Pimenoff says.

Towards more personalised screening

The studies described above address the same key question: how cancer prevention can be developed in a situation where risk factors are changing in different ways across population groups.

As the risk of cervical cancer decreases among the vaccinated, screening may in the future be targeted at risk groups. At the same time, entirely new methods are needed for the early detection of oropharyngeal cancers.

“By combining information on the changing ecology of the virus population with early biological markers in individuals, it will be possible in the future to identify cancer risk earlier than at present and to prevent disease more effectively,” Pimenoff concludes.

The studies are funded by the Cancer Foundation Finland.