[Impact of life expectancy on the clinical significance and curability of prostate cancer].

Theoretical projected prostate cancer volume at the time of expected death was determined based on patient age and index cancer volume at diagnosis, assumed cancer volume doubling time and life expectancy of Japanese male population. Clinically insignificant cancer in 104 prostatectomy specimens was found to occur at 4.8, 10.6, 15.4 and 26.9% for tumor doubling times of 2, 3, 4 and 6 years, respectively. Assuming a 2-year doubling time with clinically insignificant cancer excluded, only 36.4% of significant cancers could be considered potentially curable and with a 3-year doubling time, 32.3%. For 4- and 6-year doubling times, only 30.7% and 25.0% of the clinically significant cancers were potentially curable, respectively. Patient life expectancy and tumor doubling time significantly determine the outcome of treatment for prostate cancer especially in elderly males with higher risk of mortality.