Systematic biopsies accurately predict extracapsular extension of prostate cancer and persistent/recurrent detectable PSA after radical prostatectomy.

OBJECTIVES

To determine if methodic analysis of systematic echo-guided biopsies associated with prostatic-specific antigen (PSA) and PSA density can accurately predict the actual pathologic stage of prostate cancer (Ca P).

METHODS

One hundred patients with clinically localized (T1, T2) Ca P who underwent radical prostatectomy (RP) were preoperatively staged by digital rectal examination (DRE), measurement of serum PSA (Yang Pros-check) and PSA density (PSAD), and transrectal echo-guided systematic biopsies (three in each lobe aiming to sample prostatic capsule) to evaluate T stage, Gleason grade, number of positive biopsies, and presence of cancer in the periprostatic tissues. Radical prostatectomy specimens were processed following the McNeal method. The PSA levels were measured every month for 2 years.

RESULTS

Extracapsular disease was detected on the specimen in 45% of the patients, persistent/recurrent detectable PSA in 47% (mean follow-up 18 months). Clinical stage T2 B, presence of Gleason grade 4, PSA > 25 ng/mL, PSAD > 0.6, number of positive biopsies > 66% of the total number of cores taken had a positive predictive value (PPV), respectively, of 72%, 66%, 80%, and 87%. Periprostatic tissue was evaluable on the core biopsies in 77% of the cases. Presence of cancer in the periprostatic fat on the core biopsies had a PPV of 94% for extracapsular disease/biological recurrence.

CONCLUSIONS

The presence of extracapsular cancerous tissue on prostatic core biopsies accurately predicts extracapsular extension of Ca P. Therefore, care should be taken when performing prostate biopsies to sample the prostate capsule and surrounding tissues to obtain a more accurate staging of the disease. The second best predictor of extracapsular disease is the percentage of positive biopsies.