Researchers have developed and validated a new diagnostic test to identify high-risk prostate cancer that reduces the number of unnecessary biopsies without sacrificing the sensitivity to correctly diagnose aggressive cancer. The research paper, entitled “Prostate cancer screening in men aged 50–69 years (STHLM3): a prospective population-based diagnostic study,” was published in The Lancet Oncology.
The STHLM3 diagnostic study, which was developed by scientists at the Karolinska Institute, intends to improve the specificity of diagnosis compared to PSA screening without decreasing the sensitivity to detect high-risk prostate cancer. The test includes a combination of variables, such as plasma biomarkers (PSA, free PSA, intact PSA, hK2, MSMB, MIC1), genetic variations (232 single nucleotide polymorphisms, SNPs) and clinical characteristics, such as age, disease history, prostate exam, familial history.
Dr. Henrik Grönberg, MD, Professor of Cancer Epidemiology at Karolinska Institutet and principal investigator in the study, commented in a press release, stating: “PSA can’t distinguish between aggressive and benign cancer. Today, men who don’t have cancer or who have a form of cancer that doesn’t need treating must go through an unnecessary, painful and sometimes dangerous course of treatment. On top of this, PSA misses many aggressive cancers. We therefore decided to develop a more precise test that could potentially replace PSA.”
The STHLM3 model was compared to PSA concentration, and the outcomes of the number of diagnosed high-risk cancers (sensitivity) and the number of performed prostate biopsies (specificity) were compared. The study, conducted between 2012 and 2014, included 58,818 Swedish men aged 50 to 69 years. Overall, the results were extremely positive, revealing a reduction in the number of biopsies for aggressive cancer (32%) as well as benign biopsies (44%). Importantly, the test demonstrated the same level of sensitivity as the PSA test (≥3 ng/mL) and was able to identify aggressive cancers in men with low PSA values (1-3 ng/ml), that would have otherwise gone undetected.
Although this study still needs to be validated for other ethnic groups, it represents an important step forward in the development of personalized diagnostics for prostate cancer, sparing patients of unnecessary pain and health systems of unnecessary costs.