The value of prostate-specific antigen levels in pelvic lymph nodes for diagnosing metastatic spread of prostate cancer.

Curative radical therapy for prostate cancer depends on accurate diagnosis of metastatic spread to pelvic lymph nodes. The authors measured prostate-specific antigen (PSA) levels in homogenized pelvic lymph nodes to determine the antigen's diagnostic value and its correlation with histologic findings. No PSA was detectable in the lymph nodes of either women or of men without prostate cancer. A dilution of prostate cancer tissue with nodal tissue showed that PSA is detectable in this assay to a concentration of 1:100,000. In 38 patients who underwent pelvic lymph node dissection for staging stage B prostate cancer the histologic findings were correlated with PSA content. All nine patients with histologic evidence of metastatic disease had measurable PSA in their nodes. Of the 29 patients with no histologic evidence of metastatic disease, 23 had no detectable PSA in their nodes. The six patients with negative histologic findings and positive findings for PSA had no progression of disease at 18-month follow-up. The authors conclude that the measurement of PSA in pelvic lymph nodes can add substantial information to that obtained by standard histologic examination.