Extraprostatic extension of prostatic adenocarcinoma on needle core biopsy: report of 72 cases with clinical follow-up.

OBJECTIVE

To describe the histological findings and prognosis that are associated with extraprostatic extension (EPE) on needle core biopsy of prostatic adenocarcinoma.

PATIENTS AND METHODS

We retrieved 99 cases of prostatic adenocarcinoma with EPE at initial diagnosis on biopsy from the consultation files of one of the authors between 1997 and 2009. The 72 cases that had available clinical follow-up data formed the basis of this study.

RESULTS

The mean (range) age of the patients was 64 (48-87) years, the median (mean, range) serum prostatic specific antigen level was 7.8 (64.8, 0.3-1505) ng/mL, and 60 of the patients (83%) had abnormalities on a digital rectal examination. The mean (range) number of malignant cores was 7.7 (1-23); the mean percentage of carcinoma in each core was 69.6%, and that in the core(s) with EPE was 76.8%. The mean Gleason score in the core(s) with EPE was 8, with a mean highest Gleason score per case of 8.4. Perineural invasion was detected in 54 cases (75%). Ten of 11 patients treated surgically had EPE on the radical prostatectomy (RP) specimen; also six had positive resection margins, five showed invasion into the seminal vesicles and one had lymph node metastasis. The Gleason scores in nine of the RP specimens did not differ from the highest grade found in the associated biopsies (score 9 in three, 8 in two, 7 in four); in one case it increased (from score 6 to 8) and in one it decreased (from score 9 to 8). Patients were followed for a mean (median, range) of 2.9 (2, 0.1-9) years, with metastases identified in 29 (40%); 10 (14%) died from the disease.

CONCLUSION

EPE on needle core biopsy of the prostate is strongly associated with extensive, high-grade prostatic adenocarcinoma, such that its usefulness as an isolated prognostic factor is relatively limited.