[Etiologic correlations of prostate cancer in Guangdong, China to family history of cancers, and sexual and marital factors-a case-control study].

ABSTRACT

BACKGROUND & OBJECTIVE: Prostate cancer is a common cancer in American and European men. The incidence of prostate cancer is low in China, but increases year by year. The previous etiologic studies on prostate cancer in China were mainly conducted in Shanghai, Wuhan, and Beijing, but rarely in Guangdong. This study was to explore the etiologic correlations of prostate cancer to sexual and marital factors and family history of cancers among Cantonese. METHODS: A hospital-based case-control study was conducted from 2005 through 2006 in 4 affiliated hospitals of Sun Yat-sen University. The cases and controls were matched by age (+/-5 years), sex, race and resident location. All the subjects were interviewed by experienced investigators. The data were analyzed with conditional Logistic regression model. RESULTS: A total of 186 subjects were investigated in this study, including 62 patients with prostate cancer, 62 with benign prostatic hyperplasia (BPH) and 62 with other diseases as controls. When BPH was referred to, an increased prostate cancer risk was seen for the men with the age at the first spermatorrhea of less than 15 as compared with those with the age of over 18 [odds ratio (OR) = 6.37, 95% confidence interval (CI) = 0.63-63.95]. The men with the first sexual activity in early age were at higher risk of prostate cancer than those in the age of over 30 (in the age of 20-24, OR = 2.25, 95% CI = 0.75-6.71; in the age of 25-29, OR = 2.34, 95% CI= 0.89-6.13). A decreased risk of prostate cancer was found among those men who lost sexual activity after 60 years (in the age of 60-69, OR = 0.51, 95% CI = 0.20-1.27; in the age of over 70, OR = 0.31, 95% CI = 0.08-1.24). When other diseases were referred to, the men with 1 first-degree relative suffered from cancer had greater risk to develop prostate cancer than those without family history of cancers (OR = 2.25, 95% CI = 0.69-7.31). Compared with the age of over 30, an earlier age of the first sexual activity increased the risk of prostate cancer (in the age of less than 20, OR = 5.07, 95% CI = 0.50-51.46); A decreased risk of prostate cancer was also found in the men without sexual activities after 60 years (in the age of 60-69, OR = 0.55, 95% CI = 0.24-1.26; in the age of over 70, OR = 0.41, 95% CI = 0.11-1.47). CONCLUSIONS: Earlier age of the first spermatorrhea and the first sexual activity may increase the risk of prostate cancer. Positive family history of cancers in first-degree relatives can promote the incidence of prostate cancer.