[Risk factors of prostate cancer in urban Qingdao: a case-control study].

Objective:To investigate the risk factors of prostate cancer in urban Qingdao and provide some theoretical evidence for the scientific prevention and treatment of the disease.Methods:We performed a hospital-based matched case-control study in Qingdao Municipal Hospital.The cases and controls were matched in age,gender,nationality and the place of residence.All the subjects were interviewed face to face in the hospital using a questionnaire,and the data analyzed by the conditional logistic regression method.Results:According to the 258 valid questionnaires collected,the prostate cancer risk was significantly higher in the cases with a family history of cancer than in those without(OR=2.58),and so was it in the men with the first spermatorrhea at the age of ≤15 years than in those at the age of ≥18 years(OR=2.27).A decreased risk of prostate cancer was found among the men with the first experience of sexual intercourse between 25 to 30 years of age(OR=0.76).An increased risk was shown in those with sexual intercourses ≥4 times per week before 35 years old(OR=2.57),masturbations ≥3 times per week(OR=2.30) and a drinking history(alcohol ≥150 g/d) of ≥10 years(OR=2.83).Conclusion:Positive family history of cancer,earlier age of the first spermatorrhea,sexual intercourses ≥4 times per week before 35 years old,frequent masturbations,and heavy drinking for more than 10 years are risk factors for prostate cancer.