A new study by Swedish researchers provides no support for a previously suggested link between male fertility and prostate cancer (PCa) risk.
A team led by Pär Stattin, MD, Umeå University, Umeå, Sweden, performed a nationwide, population-based, case-control study. The study included 96,301 PCa cases and 378,583 matched controls. A total of 1,112 cases and 4,538 controls had fathered dizygotic twins, a marker of high fertility.
Compared with the fathers of singletons, men who fathered dizygotic twins did not have an increased risk of PCa, the investigators reported online in PLoS One. The study also found that men with a high education level had an increased risk of PCa compared with men who had a low educational level. Divorced, never married men, and widowers, were at decreased risk of PCa compared with married men.
Previous large population-based observational studies had found a higher risk of PCa among fathers compared with childless men, Dr. Stattin and his colleagues noted. A possible explanation for this increased risk is that androgen levels are higher in fathers than in infertile men, as androgen levels might affect PCa risk.
In conducting the study, the researchers considered the possible influence of in vitro fertilization. They noted that in vitro fertilization was introduced in Sweden in 1981, but twinning rates did not increase markedly until 1990. To avoid confounding, the researchers limited their analyses to men who had fathered children prior to 1991.