We conducted mass screenings for prostate diseases on male subjects over fifty years of age in three separate areas in Hokkaido. Prostate carcinoma and benign prostatic hypertrophy were searched in the 1, 764 participants.
Histopathologically proven prostate carcinoma was found in twenty-two (1.25%) of the 1, 764 participants. This frequency of carcinoma was higher than any other carcinoma found in the mass screenings for gastric, uterine, breast and lung carcinoma in Hokkaido. Of the 22 prostate carcinomas found, 68% were in the early stage (stage B). This stage distribution was clearly distinct from that of prostate carcinoma found on the hospital visit, most of which had already progressed to an advanced stage. These results indicate that mass screening for prostate carcinoma on ≥50 year old-male subjects is efficient in finding carcinoma of all stages but, in particular, carcinoma of early stage, when compared with mass screening for other carcinomas.
BPH, defined as a moderately or markedly enlarged prostate on rectal palpation, was found in 10% of the participants. Questionnaire on subjective symptoms of voiding disturbance in the participants has confirmed that these symptoms, mainly elicited by BPH, become manifested in fifties and more frequent with age.
Of thirteen patients with prostate carcinoma who received both rectal examination and prostate-related markers measurement in serum at the time of mass screening, three without induration of the prostate were diagnosed as having carcinoma from an abnormal value of the serum markers. This result suggests that the marker(s) is one of the useful screening tests for detecting carcinoma. However, the most appropriate system for marker determination (single or combination assay) and its cost-benefit issue remain to be determined.