A new model to identify patients with high-risk prostate cancer may decrease unnecessary biopsies without underdiagnosing prostate cancer, a new study published online ahead of print in the journal The Lancet Oncology has shown.1
Because the prostate-specific antigen (PSA) test, which is used to screen for prostate cancer, has a high false-positive rate that translates into unnecessary prostate biopsies and overdiagnosis of low-risk disease, researchers in Sweden sought to develop and validate a model to identify high-risk prostate cancer with better test characteristics than that provided by PSA screening alone.
For the prospective, population-based, paired, screen-positive, diagnostic Stockholm 3 (STHLM3) study, researchers randomly enrolled men aged 50 to 69 years without prostate cancer from the Swedish Population Register.
The predefined STHLM3 model included a combination of plasma protein biomarkers (PSA, free PSA, intact PSA, hK2, MSMB, MIC1), genetic polymorphisms (232 single nucleotide polymorphisms), and clinical variables such as age, family history, previous prostate biopsy, and prostate exam. Both the new model and PSA concentration were tested in all enrolled participants.
Results showed that the STHLM3 model performed significantly better than PSA alone for detection of cancers with a Gleason score of at least 7 (P < .0001). Researchers found that all variables used in their model were significantly associated with prostate cancers with a Gleason score of at least 7 (P < .05).
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The study also demonstrated that use of the STHLM3 model could reduce the number of biopsies by 32% (95% CI, 24 – 39) and could avoid 44% (95% CI, 35 – 54) of biopsies for benign tumors.
“The STHLM3 model could reduce unnecessary biopsies without compromising the ability to diagnose prostate cancer with a Gleason score of at least 7, and could be a step towards personalized risk-based prostate cancer diagnostic programs,” the authors concluded.
- Grönberg H, Adolfsson J, Aly M, et al. Prostate cancer screening in men aged 50-69 years (STHLM3); a prospective population-based diagnostic study [published online ahead of print November 9, 2015]. Lancet Oncol. doi: 10.1016/S1470-2045(15)00361-7.