Lower incidence of unsuspected lymph node metastases in 521 consecutive patients with clinically localized prostate cancer

Between 1983 and 1991 we saw 521 consecutive patients who elected to undergo radical prostatectomy for clinically localized prostatic carcinoma. We performed staging pelvic lymphadenectomy to avoid radical prostatectomy in patients with pelvic lymph node metastases who would be unlikely to be cured by the operation. However, we found that significantly fewer patients had lymph node metastases than historical reports would have led us to predict. Of 32 patients with clinical stage A1 disease none had positive nodes, compared to 2 of 61 (3.3%) with stage A2, 10 of 189 (5.3%) with stage B1 and 23 of 236 (9.7%) with stage B2 disease. We conclude that this lower incidence of nodal involvement relative to previous reports reflects a true change in the stage at which prostate cancer currently is diagnosed. We postulate that a higher index of suspicion, earlier detection, more aggressive intervention to establish the diagnosis, use of ultrasound guided prostate biopsies and more widespread screening for prostate cancer contribute to the lower incidence of occult lymph node metastases in patients with clinically localized prostate cancer.