Any proportion of ductal adenocarcinoma in radical prostatectomy specimens predicts extraprostatic extension

Summary 

Ductal adenocarcinoma of the prostate is an aggressive malignancy, often presenting at an advanced stage. In mixed ductal and acinar adenocarcinomas, the relationship between the proportion of the ductal component of the tumor and the pathologic stage and whether or not aggressive behavior is simply a function of grade remains undetermined. From 268 consecutive radical prostatectomies undertaken as a curative procedure for clinical localized prostate cancer, we identified 34 cases (12.7%) with ductal adenocarcinoma of the prostate comprising 5% to 100% of the total tumor volume. For cases with a ductal adenocarcinoma of the prostate component, the mean age at diagnosis of 60 years (range 49-69 years), mean serum prostate-specific antigen of 8.4 ng/mL (range, 0.8-21 ng/mL) and positive surgical margin rate of 17.6% did not differ significantly from that of the pure adenocarcinoma group. All 34 patients with ductal adenocarcinoma of the prostate had peripheral zone involvement while 16 (46%) also had transition zone involvement. Twenty-five (73%) cases with ductal adenocarcinoma of the prostate had extraprostatic extension (pT3), which compared to 32.9% with acinar adenocarcinoma. The presence of ductal adenocarcinoma of the prostate (P < .0001), high tumor volume (P = .001) and Gleason score >7 (P = .04) significantly predicted pT3 staging category, and the presence of ductal adenocarcinoma of the prostate remained a significant predictor for pT3, after adjusting for tumor volume and Gleason score >7. The proportion of ductal adenocarcinoma of the prostate did not significantly modify the strength of the observed association with pathological stage. In view of the significant association with extraprostatic extension we would recommend that in both core biopsies and radical prostatectomy specimens any proportion of ductal adenocarcinoma of the prostate should be reported.

Keywords: Prostate, Adenocarcinoma, Ductal adenocarcinoma, Tumor stage, Gleason grade