Epidemiological study of prostatic cancer by matched-pair analysis.

In 1976, we designed an original questionnaire, consisting of 111 questions, directed at the epidemiology of prostatic disease. A case-control study by matched-pair analysis was conducted on 100 controls matched for age within 1 year and for residence in the same prefecture. Patients with prostatic cancer were distinguished from the general population of men by the following characteristics: 1) belonging to middle or lower socioeconomical class, 2) marriage at a young age and a long married life, 3) precocity, 4) vigorous sexual life followed by a fall-off of sexuality in later life, and 5) Western food habits. Based on analysis of results obtained in this case-control study, a high-risk group for prostatic cancer was outlined.