[Clinical characteristics of prostatic adenocarcinoma with ductal features]

To determine the incidence and prognosis of prostatic ductal adenocarcinoma.

From November 2002 to December 2005, we performed 122 radical prostatectomies and pelvic lymph node dissections. We further analyzed 64 cases after excluding 56 cases that had received neoadjuvant hormone therapy and two cases for which we were only able to perform limited follow-up examinations. We reviewed all of the surgical specimens and reclassified them according to the 2004 WHO classification system. We differentiated prostatic cases of ductal adenocarcinoma that were larger than 5 mm in diameter from cases of acinar adenocarcinomas. We then examined these two groups for the pathological stages of the neoplasms and the incidence of postoperative prostate-specific antigen (PSA) failure. Postoperative PSA failure was defined as a PSA value more than 0.2 ng/ml.

We found eight cases (12%) of prostatic ductal adenocarcinoma among the 64 cases treated with radical prostatectomies. The mean age (+/- SD) of these patients was 65.3 (+/- 4.3) years old, and the mean PSA level (+/- SD) was 12.4 (+/- 5.4) ng/ml. Seven of the cases (11%) were mixed-type ductal adenocarcinomas, which contained acinar and ductal components. In addition, one case was identified as pure ductal adenocarcinoma. Seminal vesicle invasion was detected in four cases and lymph nodes metastases were identified in one case. During the follow-up period, four of the eight cases of ductal adenocarcinoma (50%) and twelve of the 56 cases of acinar adenocarcinoma (21%) showed postoperative PSA failure. The median follow-up period was 24 months (range: 12 to 48 months).

We identified eight cases of ducal adenocarcinoma (12% of the examined cases), which suggests this disease is not as rare as previously reported. Compared to the cases of acinar adenocarcinoma, the cases of ductal adenocarcinoma were at a more advanced pathological stage and resulted in a higher rate of postoperative PSA failure. Therefore, we believe that patients that show even a limited degree of ductal adenocarcinoma should receive aggressive therapy.