[Prostate cancer in the transition zone in sympatomatic patients with no rectal signs and negative peripheral zone biopsy].

Objective: To evaluate the incidence of transition zone prostate cancer in patients with symptoms of benign prostatic hyperplasia, elevated PSA values, negative DRE and central and transition zone biopsies in order to determine the risk factors in the subgroup of patients with a high incidence of transition zone prostate cancer.

Methods: Of 541 patients with benign histological findings on ultrasound-guided transrectal prostatic peripheral and central zone biopsies, 125 (23%) underwent prostatic surgery. The mean age was 68.2 +/- 6.8 years, the mean PSA value was 16.5 +/- 25.9 ng/ml (Hybritech).

Results: Transition zone prostate cancer was found in the surgical specimen of 11.2% of the patients. No significant differences were found between patients with and without cancer for age, PSA and PSAD values, prostate size, nodules on ultrasound, or number of biopsies performed. Patients with stage Tb1 prostate cancer showed much higher PSA levels than those with stage T1a cancer (p = 0.06). Only one stage T1a cancer was found (4%) in patients < or = 70 years with PSA values < or = 10 ng/ml, while 12.5% of the cancers were found in patients < or = 70 years with PSA > 10 ng/ml (p = 0.2).

Conclusions: The incidence of transition zone prostate cancer in this series was 11.2%. The incidence of cancer and the probability of tumor progression are higher in the subgroup of patients < or = 70 years with PSA > 10 ng/ml. Hypothetically, had ultrasound-guided transition zone biopsies been performed in this subgroup of patients, one case of stage T1a prostate cancer (11%) would not have been diagnosed but biopsy would have been avoided in 41% of the patients.