PATHOLOGICAL AND CLINICAL FINDINGS TO PREDICT TUMOR EXTENT OF NONPALPABLE (STAGE-T1C) PROSTATE-CANCER

Objectives.-We examined preoperative clinical and pathologic parameter s in men with clinical stage T1c disease who underwent radical prostat ectomy and correlated these findings with the pathologic extent of dis ease in the surgical specimen in an attempt to identify a subset of pa tients with potentially biologically insignificant tumor who might be followed up without immediate treatment.Design and Patients.-A case se ries of 157 consecutive men who underwent radical prostatectomy for cl inical stage T1c disease compared with 64 similarly treated clinical s tage T1a cancers (incidental minimal cancers found on transurethral re section of prostate) and 439 clinical stage T2 (palpable) cancers. Mai n Outcome Measures.-Pathologic stage, grade, and margins; tumor volume ; and tumor location. Results.-Sixteen percent of tumors were insignif icant (<0.2 cm3 and confined to the prostate, with a Gleason score <7) ; 10% were minimal (0.2 to 0.5 cm3 and confined to the prostate, with a Gleason score <7); 37% were moderate (>0.5 cm3 or capsular penetrati on, with a Gleason score <7); and 37% were advanced (capsular penetrat ion, with a Gleason score greater-than-or-equal-to 7 or positive margi ns, seminal vesicles, or lymph nodes). These findings are intermediate between those found in clinical stage T1a and stage T2 disease. The f ollowing parameters were not predictive of tumor extent: age, reason f or evaluation, method of detection, and transrectal ultrasound. The be st model predicting insignificant tumor was prostate-specific antigen (PSA) density less than 0.1 ng/mL per gram and no adverse pathologic f indings on needle biopsy, or PSA density of 0.1 to 0.15 ng/mL per gram , with a low- to intermediate-grade cancer smaller than 3 mm found in only one needle biopsy core specimen. The positive predictive value of the model was 95%, with a negative predictive value of 66%. We accura tely predicted 73% of cases with insignificant tumor. Conclusions.-Eig hty-four percent of nonpalpable prostate cancers diagnosed by screenin g techniques are significant tumors and warrant definitive therapy. Ho wever, 16% are insignificant. Serum PSA level, PSA density, and needle biopsy pathologic findings are accurate predictors of tumor extent. l t may be reasonable to follow up some patients whose tumors are most l ikely insignificant with serial PSA measurements and repeated biopsies .