Fatherhood may increase the risk of prostate cancer

Research by Danish scientists has found that fatherhood can increase a man's risk of developing prostate cancer.

A study conducted by researchers at Statens Serum Institut in Copenhagen found that men who had never fathered a child had a lower risk than men who had fathered a child of developing the disease, but in contrast men who had fathered many children also had a low risk.

Lead author Kristian T. Jorgensen of the Statens Serum Institut in Copenhagen and colleagues followed all men born in Denmark between 1935 and 1988, and found that compared with fathers, childless men were 16 percent less likely to develop prostate cancer.

Confusing as this may appear the researchers say it is unclear why but there is an obvious link between men who do not father a child and a decreased risk of prostate cancer.

One theory suggested is that childless men may be infertile and therefore have lower levels of the male sex hormones androgens; androgens have repeatedly been associated with an increased risk of prostate cancer, but this has yet to be proven.

The researchers say more research is needed to understand the "biologic, environmental, social and/or behavioural factors" that underlie the findings.

The study is published in the journal Cancer.