Some infertile men have heightened cancer risk

Men who don’t produce sperm face nearly three times the risk of cancer compared with the male population average, researchers report June 20 in Fertility and Sterility.

About 4 million men in the United States are infertile, with a host of causes. Of them, about 600,000 men don’t deliver sperm from the testes to the semen at all.

Michael Eisenberg of Stanford University and his colleagues studied the medical records of Texas men who had visited a male health clinic between 1989 and 2009. The men averaged 36 years old when they were examined. Of 2,238 men found to be infertile, about one-fifth didn’t have any sperm in their semen.

Over an average follow-up time of 6.7 years, 10 of the 451 men who didn’t make sperm developed some kind of cancer, making them 2.9 times as likely as similar-aged men in the general Texas population to be diagnosed with cancer. The reason is unclear, the authors say. Men who were infertile for other reasons didn’t face an increased risk of cancer.