Progression of prostatic cancer in relation to age in patients detected by mass screening program

With the aim of revealing the natural history of prostatic cancer, the distribution of age was examined in relation to disease progression in patients detected by mass screening programs. Between 1975 and 1996, such programs detected a total number of 132 patients with prostatic cancer. The mean ages of patients with Stage B, Stage C and Stage D disease were 71.2, 73.8 and 75.3 years, respectively. This might suggest that the difference of 3 years in mean age between Stage B and Stage C disease reflects the time interval of the progression of prostatic cancer from the early (Stage B) to the advanced (Stage C) stage. These results coincided well with the natural history of prostatic cancer, which we proposed previously based upon the "size of ranking" analysis of latent prostatic cancer and doubling time obtained from ultrasonic measurement of prostatic volume. An epidemiological study of prostatic cancer detected by mass screening would offer data of value for the elucidation of the natural history of that disease.