The combination of a novel blood test and MRI can reduce overdiagnosis of low-risk cancers as well as societal costs in prostate cancer screening, according to a cost-effectiveness study from Karolinska Institutet published in the journal European Urology. The results provide support for organized prostate cancer testing in Sweden, researchers say.

A barrier to the introduction of nationwide prostate cancer screening has been that PSA (prostate-specific antigen) tests combined with traditional biopsies result in the detection of numerous minor low-risk tumors. MRI has been shown to reduce this overdiagnosis but presents a challenge due to limited health resources. 

The STHLM3MRI trial has previously shown that a blood test called Stockholm3, developed by researchers at Karolinska Institutet, can reduce the number of MRIs by a third for a single screening occasion. Now, the same research group reports that this combination is also considered cost-effective in Sweden compared with both no screening and PSA test in MRI-based screening.

Further Reduction in MRI

“Our latest results show that using Stockholm3 reduces the number of MRIs over a lifetime by 60%. This also avoids unnecessary biopsies by 9%, which reduces the overdiagnosis of low-risk cancers,” says Mark Clements, associate professor at the department of medical epidemiology and biostatistics, Karolinska Institutet, who is responsible for the cost-effectiveness study.

The analysis predicted that MRI-based screening combined with PSA or Stockholm3 would reduce prostate cancer-related deaths by 7%-9% over a lifetime compared with no screening at all. The health economic evaluation showed that, compared with no screening, screening with PSA followed by Stockholm3 and MRI in high-risk individuals is classified as a moderate cost per quality-adjusted life-years (QALY) gained as defined by the Swedish National Board of Health and Welfare. 

“This new combination with Stockholm3 can save healthcare resources and reduce societal costs while maintaining the health benefits from early detection of prostate cancer. This presents an interesting option for prostate cancer screening in Sweden,” says Shuang Hao, PhD student at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet and the first author of the study.