Histological characteristics of radical prostatectomy specimens in men with a serum prostate specific antigen of 4 ng./ml or less.

PURPOSE

Of most reported radical prostatectomy series 20% consist of men with a serum prostate specific antigen (PSA) of 4.0 ng./ml. or less. Since our series is not only prospective but all prostates are reconstructed at 3 mm. intervals, we determined the clinical and histological findings in this important subset of men undergoing radical prostatectomy.

MATERIALS AND METHODS

Of 911 consecutive men undergoing radical prostatectomy 187 (21%) had a preoperative serum PSA of 4.0 ng./ml. or less (values equivalent to those of the Hybritech Tandem-R assay).

RESULTS

Mean tumor volume was 2.3 cc. Of the 187 cancers 156 (83%) were in the peripheral zone and 31 (17%) in the transition zone, while 137 (73%) were organ-confined and 50 (27%) showed capsular penetration. No patient had positive pelvic lymph nodes, only 5 had seminal vesicle invasion and positive surgical margins were present in 14%. Cancer volumes less than 0.5 cc were noted in 9% of the patients and were probably insignificant. At an average followup of 37 months, only 16 men (9%) had a detectable serum PSA. These 16 patients had a larger tumor volume (3.7 cc versus 2.2 cc, p < 0.05), and a greater percent of Gleason grade 4 and/or 5 disease than the 171 with undetectable PSA.

CONCLUSIONS

Men with prostate cancer and a serum PSA of 4.0 ng./ml. or less are excellent candidates for radical prostatectomy if the 9% with clinically insignificant tumors can be avoided. Since 70% of all men had a suspicious prostate on digital rectal examination, this evaluation is important for men with a serum PSA of 4.0 ng./ml. or less.