Single focus of adenocarcinoma in the prostate biopsy specimen is not predictive of the pathologic stage of disease

Objectives. To determine whether a very small focus of prostate cancer in a needle biopsy specimen correlates with organ-confined disease or with favorable disease parameters. Methods. Of 598 needle biopsies of the prostate performed from January 1990 through June 1994, 49 specimens (8.2%) contained a microscopic focus (less than 2 mm in length of the entire biopsy core specimen) of adenocarcinoma. For these 49 patients, the clinical and pathologic features were correlated. Results. Of these 49 patients, 27 (55.1%) underwent either radical prostatectomy, with or without pelvic lymph node dissection (26), or pelvic lymph node dissection alone (1). Seven of these 27 patients (25.9%) had extraprostatic disease: lymph node involvement (1), positive surgical margins (5), or seminal vesicle invasion (1). Ten of the 49 patients (20.4%) underwent radiotherapy, and 12 (24.5%) chose hormonal therapy. The pathologic stage for these 22 patients could not be ascertained. However, despite the limited amount of disease in the biopsy specimen, 2 patients treated with radiotherapy suffered a relapse (mean interval to recurrence, 11.5 months), and 3 patients treated with hormonal therapy (early or delayed) had bony metastasis at the time of diagnosis. Overall, 12 of the 49 patients (24.5%) had unfavorable disease (as defined by extraprostatic disease on pathologic specimen, relapse after radiotherapy, or bony metastasis at the time of diagnosis). Conclusions. These findings suggest that a microscopic focus of prostatic adenocarcinoma in a needle biopsy specimen, per se, does not predict the pathologic stage or the biologic behavior of a tumor.