Influence of circumcision and sexual behaviour on PSA levels in patients attending a sexually transmitted disease (STD) clinic

Abstract

Early age at first intercourse, increased number of sexual partners, lack of circumcision and history of sexually transmitted diseases (STDs) are associated with prostate cancer. There has been no investigation of the effect of these factors on prostate health at an early age. Previously collected serum samples from STD clinic attendees were tested retrospectively for anti-chlamydial antibodies, and prostate specific antigen (PSA) concentration. Patients at an STD clinic were interviewed regarding age of first intercourse, number of sexual partners and circumcision status. This was compared to clinical diagnosis, anti-chlamydial antibody titre and PSA concentration. The results showed: (1) that of patients with an anti-chlamydial antibody titre equal or greater than 1 in 64 (n=27) 37% had a PSA concentration greater than 0.8 ng/ml while those with a titre less than 1/64 (n=201) only 17% had a PSA >0.8 (P<0.05). (2) No association was found with circumcision status. (3) Early age of first intercourse and more than 20 sexual partners were associated with a synergistic increase in mean anti-chlamydial antibody titre and a mean PSA concentration of 1.2 ng/ml (95% CI 0.56–1.76). It is concluded that these results provide the first evidence that sexual behaviour related risk factors for prostate cancer do damage the prostate at an early age. Though they do not prove that infection is a cause of prostate cancer they do justify further research into the specificity of agents involved and impact of antibiotic treatment.