Retrospective study of 101 cases with incidental prostate cancer stages T1a and T1b

The purpose of this retrospective study was to clarify the character of incidental prostate cancer, stages T1a and T1b.

We analysed 101 cases of incidental prostate cancer. Incidental prostate cancer was diagnosed on the basis of normal digital rectal examination findings, a serum prostate-specific antigen (PSA) level of less than 4.0 ng/mL, and no abnormal computed tomography or ultrasonography findings. All patients were treated at Gifu University Hospital or an affiliated hospital during the period January 1992 through December 2001.

There were 64 stage T1a cancers and 37 stage T1b cancers. The mean age of patients was 71.3 years (range 51-87 years). The mean serum PSA level was 1.63 ng/mL (range 0.2-4.0 ng/mL). Thirty-five stage T1a patients (56.5%) and thirty-two stage T1b patients (86.5%) underwent some type of treatment. Total prostatectomy was performed in eight stage T1a cases and fifteen stage T1b cases. Pathological diagnoses were as follows: pTx (n = 1), pT0 (n = 5) and pT2 (n = 2) for stage T1a cancers, and pT0 (n = 6), pT2 (n = 8) and pT3 (n = 1) for stage T1b cancers. Only one stage T1b cancer recurred.

The outcome of patients with incidental prostate cancer was satisfactory; disease recurred in only one case of stage T1b cancer and there were no cases of PSA failure, although the pathological diagnosis in nine of the fifteen stage T1b cases (60.0%) treated with total prostatectomy was pT2 or pT3. Careful monitoring was indicated for stage T1a cancer, and some treatment was necessary for stage T1b cancer.