Objective: Study of the value of a single positive prostatic biopsy in the staging of prostatic carcinoma and the significance of the tumour volume.
Method: The clinical, laboratory and pathological parameters were studied in 27 prostatectomized patients with a single positive prostatic biopsy.
Results: The length of tumour invasion on the biopsy was 2.6 mm (evaluation on 25 biopsies). Six patients (23%) had an extracapsular tumour and 21 (78%) had a significant tumour volume. Among the 16 patients with a length of tumour invasion < or = 3 mm, 13 (81%) had a significant tumour volume. 25% of patients with less than 3 mm of invasion on the biopsy and a Gleason score < or = 6 and 12% of patients with less than 3 mm of invasion and a PSA < or = 10 ng/ml had a non-significant tumour volume.
Conclusion: The presence of a single positive prostatic biopsy is not sufficient to determine the pathological stage of a prostatic carcinoma. In this retrospective study, the majority of patients with a single positive biopsy had a significant tumour volume > 0.5 cc. No preoperative predictive factor of tumour volume was demonstrated.