Initial high-grade prostatic intraepithelial neoplasia with carcinoma on subsequent prostate needle biopsy: Findings at radical prostatectomy

There are only a few small studies on men with an initial biopsy showing high-grade prostatic intraepithelial neoplasia (HGPIN) who later have cancer on repeat biopsy and then undergo radical prostatectomy. It is unknown whether this scenario impacts the prognosis of subsequent radical prostatectomy. We compared radical prostatectomy findings in 45 men with an initial diagnosis of HGPIN who subsequently were diagnosed with cancer with 18,494 men diagnosed with cancer who lacked an earlier diagnosis of HGPIN. All cases were retrieved from our institution between 1993 and 2008. The mean patient age was 60.2 years, and the mean serum prostate-specific antigen value was 9.0 ng/mL. For the 45 men with an initial HGPIN diagnosis, 21 of 45 (46.7%) men were found to have cancer within 6 months and 29 of 45 (64.4%) within 1 year after the diagnosis of HGPIN. Cancer involved a single core in 32 of 45 (71.1%) cases, and the maximum tumor volume was ≤5% in 57.8% of the 45 cases. Men with initial HGPIN had 84.4% organ-confined cancer, whereas cases without HGPIN had 65.4% organ-confined cancer (P=0.007) at radical prostatectomy. For the RPs performed in men with an earlier diagnosis of HGPIN followed by cancer on biopsy, the mean and median tumor volumes were 0.3 cm³ and 0.12 cm³ (0.003 cm ³ to 1.46 cm³). Favorable pathologic stage was maintained even when we restricted the analysis to men with only Gleason score 6 cancer on biopsy. In men with Gleason score 6 cancer on biopsy, men with an initial diagnosis of HGPIN had 88.9% organ confined versus 73.2% for men with no earlier biopsy diagnosis of HGPIN, (P=0.03). At radical prostatectomy, although men with an earlier HGPIN diagnosis had less adverse findings in terms of Gleason score, surgical margin involvement, seminal vesicle involvement, and lymph node metastasis, the differences did not reach statistical significance. This was possibly due to the relatively small number of positive events in the men with no earlier HGPIN and due to the relatively small number of cases with earlier HGPIN. Prostatic adenocarcinomas discovered after an initial HGPIN diagnosis on biopsy are more likely to be organ confined, yet of similar grade, compared with cases diagnosed as cancer on the first biopsy. These findings likely reflect cancers associated with HGPIN, in which the cancers were missed on the initial biopsy as a result of smaller size.