Blog | Tuesday, March 13, 2012

QD: News Every Day--Circumcision may cut prostate cancer risk

Circumcision before first sexual intercourse is associated with a lower risk of prostate cancer, suggesting that the disease, like many other cancers, sometimes has an infectious source.

Circumcisions reduce the rates of infection from sexually transmitted diseases, and now researchers are establishing the next step--fewer infections may results in fewer cancers.

They conducted a population-based, case-control study of prostate cancer in King County, Washington, with prostate cancer reported in the Seattle-Puget Sound Surveillance, Epidemiology, and End Results (SEER) cancer registry. Self-reported circumcision status, age at circumcision, and age at first sexual intercourse were recorded along with a history of sexually transmitted infections or prostatitis.

Results appeared in Cancer on March 12.

Data from 1,754 cases and 1,645 controls were compared. Circumcision before first sexual intercourse was associated with a 15% reduction in risk of prostate cancer compared to that of uncircumcised men (95% confidence interval [CI], 0.73 to 0.99). This risk reduction was observed for cases with both less aggressive (odds ratio [OR], 0.88; 95% CI, 0.74 to 1.04) and more aggressive (OR, 0.82; 95% CI, 0.66 to 1.00) prostate cancers.

The authors noted that infections are estimated to be the cause of 17% of cancers, including:
--Viruses: HHV8 and Kaposi’s sarcoma; hepatitis B and/or C and liver carcinoma; HPV and cervical/anal/genital carcinoma;
--Bacteria: Helicobacter pylori and gastric carcinoma;
--Parasites: Schistosomiasis haematobium and bladder carcinoma

Infections may cause chronic inflammation, with leads to a cascade of events that ultimately damage DNA, the authors reported. Viruses can dig into DNA, causing the cells to change. And, diseases can impair immunity, and the body's ability to eradicate tumor cells.