About one in six infertile men have azoospermia, or no viable sperm in their ejaculate, and these men may be at the highest cancer risk, a new study shows.
For the study, published online in the journal Fertility and Sterility, researchers evaluated 2,238 men, average age 36, at a fertility clinic in Texas; 451 had azoospermia. They found 29 cases of cancer during an average follow-up of almost seven years.
Over all, those in the infertile group were 1.7 times as likely as the general population in Texas to develop some form of cancer. But the risk more than tripled for those with azoospermia.
While the increase in relative risk is substantial, the authors write, the absolute risk of cancer in this population remains low.
"The main message here is to continue follow-up after a fertility workup," said the lead author, Dr. Michael L. Eisenberg, an assistant professor of urology at Stanford.