Changes in the Practice Patterns and Outcomes of Transrectal Ultrasound-Guided Prostate Biopsy
Andrew J. Hung, Michael J. Schwartz, David H. Hwang, Justin W. McClain, Jullet Han, M. Mendel Shemtov, Alexis E. Te, R. Ernest Sosa, E. Darracott Vaughan Jr., Douglas S. Scherr
Department of Urology, New York Presbyterian Hospital, Weill Medical College of Cornell University
Objective: We reviewed all transrectal ultrasound (TRUS) guided prostate biopsies performed at our institution over the past 13 years to examine how biopsy practice patterns and outcomes have changed over time.
Methods: With Institutional Review Board approval, a database of all TRUS guided prostate biopsies performed from August 1993 through December 2005 was compiled from a retrospective chart review. Patients with prior intervention potentially affecting PSA were excluded. Patient age, PSA, digital rectal exam (DRE), indication for biopsy, number of cores, prostate volume, and biopsy results were recorded. We examined the data for changes in any of these parameters over time to determine if the positive biopsy rate was affected by any changes in practice patterns.
Results: 2,861 prostate biopsies were performed at our institution over 13 years. Of these, 1,108 biopsies were performed which met criteria and with all parameters available at the time of this study. We found the percentage of patients with an abnormal DRE has decreased over time. The number of patients undergoing biopsy for PSA criteria alone has concurrently increased over time. The PSA cutoff used as an indication for biopsy has decreased, with 2.5 ng/ml more frequently employed in recent years. Introduction of age-specific PSA did not change biopsy practice patterns at our institution. While the number of cores taken at each biopsy has increased, the percentage of positive biopsies has decreased over time. The sensitivities of DRE and PSA both decreased, regardless of PSA cutoff used, while specificities slightly increased.
Conclusions: The decreased sensitivity and increased specificity of both PSA and DRE in the detection of prostate cancer, despite using a lower PSA cutoff as a threshold for biopsy, suggest a stage migration of prostate cancer to lower grade, smaller volume disease. The decreasing percentage of positive biopsies despite increasing numbers of cores per biopsy session is further evidence of the same trend. Efforts to increase cancer detection at a more curable point (lowering PSA cutoffs and increasing cores per biopsy), have not changed cancer detection rates. Therefore, in the present era, PSA may have limited utility in the detection of prostate cancer.