[A case-control study of environmental and genetic factors and prostate cancer in Guangdong].

Objective: To explore the etiologic relationship of prostate cancer and environmental and genetic polymorphism in southern China

Methods: A hospital-based and 1:1 matched case-control study was conducted. A total of 142 matched pairs of subjects were investigated in this study. The blood samples were collected from 85 cases of prostate cancer and 82 controls of other diseases after informing consent. The CYP1A1, CYP17 and AR genes were analyzed by using the method of PCR, PCR-RFLP. The data were analyzed with conditional logistic regression model.

Results: An increased risk of prostate cancer development was observed with the early first spermatorrhea (age < 18) (OR = 2.90, 95% CI: 1.76 - 4.80), early first sexual intercourse (age < or = 24) (OR = 2.38, 95% CI: 1.14 - 4.96), frequent sexual intercourse before 35 year old (OR = 1.80, 95% CI: 1.19 - 2.70), family history of cancer (OR = 2.70, 95% CI: 1.31 - 5.58), more intake of pork (OR =2.27, 95% CI: 1.38 - 3.70). Factors in lowing the risks were the fruit intake and drinking of green tea by OR value at 0.25 (95% CI: 0.08 - 0.75) and 0.52 (95% CI: 0.28 -0.96) respectively. CYP17 A1/A2 and CYP17 A2/A2 genotypes were related with a high risk of prostate cancer and OR values of 1.78 (95% CI: 0.70 - 4.53) and 2.57 (95% CI: 0.91 - 7.25) respectively. Study also showed that there was an interaction between CYP17 polymorphisms and early first spermatorrhea and family cancer history related to the risk of prostate cancer with OR value at 13.35 (95% CI: 1.58 - 113.00) and 4.01 (95% CI: 1.22 - 13.17) respectively.

Conclusion: Sexual intercourse, dietary intake and family cancer history should be related to prostate cancer occurrence. CYP17 polymorphism might be associated with a high risk of prostate cancer. It suggests that there are multiple environmental and genetic factors to the prostate cancer.