Trends in prostate needle biopsy diagnosis. A ten year experience of a medical center in Taiwan.

Prostate cancer has seen a rapid rise in Taiwanese men. The current study was undertaken to evaluate trends of the disease diagnosed on prostate needle biopsy during a ten-year period at the Department of Pathology, Taipei Veterans General Hospital. The study included 8236 men who underwent a total of 9995 prostate needle biopsies at this institute from 1994 to 2003. Pathologic features pertinent to diagnosis of cancer were reviewed and compared for cases diagnosed before and after 1999. There were statistically significant increases of the overall cancer detection rate (from 17.6% to 19.9%), proportion of cases with a Gleason score ≤ 6 (from 16.6% to 40.9%) and focal adenocarcinoma (from 3.0% to 12.8%) in the latter 5 years. The incidence of high-grade prostatic intraepithelial neoplasia (HGPIN) increased from 0.1% to 1.5%. Patients with HGPIN had a significantly higher risk for subsequent cancer discovered on repeat biopsy than did those with a primary benign diagnosis (29.9% versus 13.7%). Despite a relatively lower incidence of cancer and HGPIN in Taiwanese men compared with that reported in Western studies, in recent years we have found an increase of relevant diagnoses, especially cancer of limited extent and lower grade, which may represent the progress in prostate cancer diagnosis.