The findings are presented in Lancet Public Health by researchers from Karolinska Institutet, who stress the importance of proactively approaching these women as a preventative measure against cervical cancer.

In May 2020, the WHO approved a global strategy for eliminating cervical cancer as a women’s health problem. Part of the strategy is a requirement that 70 percent of women are screened for the disease at least once before age 35 and twice before age 45. 

According to the researchers, inequality of care is one of the major hurdles to this objective. 

“Our study identified a high-risk group that needs extra attention if we’re to succeed in eliminating cervical cancer,” says one of the study’s first authors Kejia Hu, postdoc researcher at the Institute of Environmental Medicine at Karolinska Institutet. 

The observational study included over four million women born between 1940 and 1995.

From this population, the researchers calculated the risk of cervical cancer and precancerous cervical lesions as well as participation in screening programs for cervical cancer, comparing women diagnosed by a specialist with mental illness, neuropsychiatric disability, or substance abuse with women without such diagnoses. 

“Our results suggest that women with these diagnoses participate more seldom in screening programs at the same time as they have a higher incidence of lesions in the cervix,” says Dr. Hu. “We thus found that they have twice the risk of developing cervical cancer.” 

Must raise awareness

An elevated risk was observed for all diagnoses, but the greatest association was noted for substance abuse. Women with mental illness should be made more aware of the need to undergo regular gynaecological screening, according to the researchers: 

Karin Sundström, senior researcher. Photo: Martin Stenmark

"It would lower their risk of cancer,” says one of the paper’s authors Karin Sundström, senior researcher at the Department of Laboratory Medicine, Karolinska Institutet. “Similarly, if healthcare professionals are more aware of the cancer risk in these patients, they can step up preventative measures and consider how these could be delivered to potentially under-served patients.” 

The strength of the study lies in the sheer size of the cohort and the length of the time-span period over which the participants were studied. One limitation is that the researchers did not have full data about other risk factors for cervical cancer such as smoking, hormonal contraceptives, and sexually transmitted diseases. 

The study was financed by the Swedish Cancer Society. One of the researchers has received fees from a pharmaceutical company for other studies. No other conflicts of interest have been reported.