Characteristics of patients with stage T1b incidental prostate cancer

OBJECTIVE: To study the characteristics of patients with incidental prostate cancer. MATERIAL AND METHODS: The proportion of incidentally diagnosed prostate cancer was investigated in patients who underwent transurethral resection of the prostate (TURP) at our clinic over a 5-year period. "True" incidental prostate cancer was defined as cases where the preoperative digital rectal examination (DRE) and the prostate-specific antigen (PSA) value were normal. Patients with known malignancy of the prostate were excluded, together with those with PSA >4 ng/ml and/or a positive DRE. The characteristics of these patients were compared to those of benign prostatic hyperplasia patients and the group as a whole. RESULTS: Of the 786 patients operated on between 1999 and 2003, 34 (4.3%) had a positive pathology report for "true" incidental prostate cancer. An increased frequency of poorly differentiated tumors (32.3%) was noted. Of the 34 patients, 17 were stage T1a and 17 T1b; 11 patients had a Gleason sum of 7-10, all of them in the T1b group. In the T1b group the mean age was 74 years, the mean PSA level 2.9 ng/ml and the mean weight of tissue resected 11.1 g. Corresponding values in the T1a patients were 70.1 years, 3.32 ng/ml and 18.2 g. CONCLUSIONS: Compared to previous studies, we noticed a low incidence of "true" incidental prostatic carcinoma but a high ratio of poorly differentiated tumors (all stage T1b). Compared to the group as a whole, patients with incidental prostate cancer were older and had smaller prostate and transition zone volumes. Further research is needed to identify parameters that may aid in the earlier identification of incidental prostate cancer, as patients may benefit from curative treatment.