Circumcision may protect against prostate cancer. A study of nearly 4,000 men found that those who were circumcised before becoming sexually active had an average 15% lower risk of cancer than uncircumcised men. They are also 18% less likely to develop an aggressive form of prostate cancer. Sexually transmitted infections are thought to contribute to the increased risk of prostate cancer. Because circumcision protects against chronic inflammation and infection, it is thought to also protect against cancer, explains Jonathan Wright of the Fred Hutchison Cancer Research Center in Seattle. The link between circumcision and the reduced risk of developing prostate cancer is not yet fully understood, but scientists believe the reason may be due to a biological mechanism. The results are published in the journal Cancer. NEWS_MORE_BOX There are many arguments against and for circumcision as a prevention of sexually transmitted diseases. The removal of the skin above the glans can be undertaken for the purpose of higher hygiene and a preventive measure against infections in the genital and excretory system. After circumcision, the glans is exposed and no smegma is collected, which reduces the risk of bacterial and viral infections. Circumcision is a way to prevent HIV infection, according to research. The data is also supported by the World Health Organization. In Africa, for example, statistics show that circumcision triples the risk of contracting the AIDS virus in heterosexual couples. Another study showed that circumcision also reduced the risk of infection with the human papillomavirus (HPV), which causes cervical cancer and other cancers.