[Effect of the natural history on management of adenocarcinoma of the prostate].

The natural history of prostate cancer has long been regarded as unpredictable. The discrepancy between histologically identifiable (40%) and clinically diagnosed carcinomas (8%) led to the term of "latent" prostate cancer and to considerable diagnostic and therapeutic dilemmas. Based on our previous studies showing that biological aggressivity of prostate cancer is a direct function of tumor volume and that tumor volume and serum PSA are proportional, we evaluated two basically different groups of patients. The first group consisted of 43 patients with untreated carcinomas of the prostate followed with serial PSA determinations. The exponential (log-linear) rise in PSA led us to the conclusion of an exponential tumor growth rate. The median doubling time of clinically organ-confined tumors was 4 years and became shorter with higher clinical stages and poorly differentiated histological grades. The second group consisted of 139 patients who underwent cystoprostatectomy for bladder cancer and had no evidence for simultaneously identifiable prostate cancer. In 55 patients (40%), unsuspected prostate cancer was found in the specimen; the volume distribution of these carcinomas was exponential. These 139 men included 11 (7.9%) who had a prostate cancer with a volume greater than 0.5 cm3, corresponding to the 8% risk for a man being diagnosed within his lifetime with a clinically significant carcinoma of the prostate. We conclude that the other 44 carcinomas, which were less than 0.5 cm3 in volume, will never reach clinical significance because of their small size and their long doubling time; in this sense they can be considered latent.(ABSTRACT TRUNCATED AT 250 WORDS)