Case-control study of prostatic cancer in Kyoto, Japan: demographic and some lifestyle risk factors.

Demographic risk factors for prostatic cancer were examined in a case-control study of 100 triplets of prostatic cancer patients and age-, hospital-, and admission date-matched control series of benign prostatic hyperplasia (BPH) patients and general hospital patients. A higher risk of prostatic cancer was associated with the following factors: 1) long-term occupation in transport or communication (relative risk [RR] = 4.92, 95% confidence interval [CI]: 1.18-20.5) as compared with hospital controls; 2) the wife having a lower educational level (RR = 1.88, 95%CI: 1.02-3.45) as compared with hospital controls; 3) no past episode of hypertension as compared with BPH controls (RR = 2.30, 95%CI: 1.27-4.15); 4) having several sisters (more than four) as compared with both BPH and hospital controls (RR = 3.82, 95%CI: 1.35-10.8 and RR = 2.94, 95%CI: 1.08-8.03 respectively); 5) dense body hair as compared with hospital controls (RR = 4.28, 95%CI: 1.19-15.4). No significant links were found with blood type, daily drug use, head hair, skin color, body type, smoking habits, religion, body weight, and mental characteristics.