Purpose: To evaluate the impact that the 2012 US Preventive Services Task Force (USPSTF) prostate-specific antigen (PSA) screening guidelines have had on the diagnosis of prostate cancer, we compared the incidence and distribution of new cases diagnosed in 2011-before the USPSTF PSA screening recommendations versus 2014 at which time the guidelines were widely adopted.
Materials and methods: We identified all prostate biopsies performed by a large urology group practice utilizing a centralized pathology lab. We examined total biopsies performed, percentage of positive biopsies, and for those with positive biopsies examined for differences in patient age, PSA, and Gleason score.
Results: A total of 4,178 biopsies were identified - 2,513 in 2011 and 1,665 in 2014. The percentage of positive biopsies was 27% in 2011 versus 34% in 2014 (p<0.0001). Among patients with positive biopsies, we found statistically significant differences between the 2 cohorts in the median ages and Gleason scores. Patients were about 1 year younger in 2014 compared to 2011 (t-test; p=0.043). High Gleason scores (8-10) were diagnosed in 19% of the 2014 positive biopsies versus 9% in the 2011 positive biopsies (chi square; p<0.0001).
Conclusions: After the widespread implementation of the 2011 USPTF PSA screening guidelines, 34% fewer biopsies were performed with a 29% increase in positive biopsy rates. We found a significantly higher incidence of high grade disease in 2014 compared with 2011. The percentage of patients with positive biopsies having Gleason scores 8-10 more than doubled in 2014. The higher incidence of these more aggressive cancers must be part of the discussion regarding PSA screening.
Keywords: Diagnosis; Gleason score; Prostate neoplasms.