MICROFOCAL PROSTATE-CANCER - BIOPSY CANCER VOLUME DOES NOT PREDICT ACTUAL TUMOR VOLUME

Objective To determine whether microfocal prostate cancer on needle bi opsy predicts clinically insignificant disease in men undergoing radic al prostatectomy. Patients and methods The records of 726 men who unde rwent radical prostatectomy between January 1990 and September 1995 we re reviewed; 83 men had pre-operative prostatic needle biopsies which revealed microfocal prostate cancer. In these men, tumour volume (leng th) in the biopsy was compared to the percentage of tumour in the tota l prostatectomy specimen, and the pathological stage and clinical outc ome reviewed. Results Of the 83 men with microfocal prostate cancer on biopsy 75 (90%) had clinically significant disease. Pre-operative var iables were of no use in identifying patients with clinically insignif icant tumour volumes. When comparing those with microfocal tumour and those without at one institution, 69% had organ-confined (pT2) disease and 31% had capsular penetration (pT3), compared with 61% and 39%, re spectively (P<0.05). Additionally, the positive surgical margin rate f or those with microfocal tumour was only 6%, compared with 26% for tho se without microfocal disease (P<0.05). Biochemical failures during th e median follow-up period of 24 months occurred in 6% of the men with microfocal cancer and in 15% of those undergoing total prostatectomy ( P<0.05). Conclusions Microfocal prostate cancer determined from the ne edle biopsy does not predict clinically insignificant disease.