When someone mentions male infertility, you probably think about the huge disappointment a couple may face when the man is unable to father a child…and that is upsetting, indeed. But male infertility is linked to another concern that has nothing to do with having a baby. It’s a cancer problem—that’s right, cancer. For men with fertility problems (and the women who love them), this newly discovered risk is very important to know about.
There are many different reasons why a man could be infertile. For instance, he might produce sperm that are misshapen or immobile and so are unable to fertilize a woman’s egg…he might produce normal sperm, but these sperm never reach the semen…he might have a problem with ejaculation…or he might produce too few sperm or none at all. It is this last condition that is of concern when it comes to cancer risk, a new study shows.
About 15% of infertile men have a condition called azoospermia, meaning a complete absence of sperm in the semen. For some such men, normal sperm are produced in the testes but some obstruction prevents them from reaching the semen. The majority of these men, however, have nonobstructive azoospermia—in which the testes don’t produce enough sperm for any to reach the semen.
A previous study noted increased rates of testicular and prostate cancers among men with fertility problems. So for this new study, researchers set out to shed additional light on this link. They used semen analyses from men who had been evaluated for infertility at a large Texas medical center. To limit the possibility that the cancer came first and was causing any participant’s infertility—rather than that the infertility came first and was a risk factor for cancer—the researchers excluded samples from men who were diagnosed with cancer within six months of their initial semen analysis.
Next, the researchers searched the Texas Cancer Registry (which records information about all cases of confirmed cancer in Texas residents) to see which of the infertile participants ended up developing some type of cancer during the study follow-up period, which lasted about six years, on average, after the semen analyses. Then they compared the cancer rates among infertile men with the cancer rates in the general population.
THE CANCER CONNECTION
What the researchers found was both reassuring and disturbing. The reassuring part was that men whose infertility was caused by something other than azoospermia had rates of cancer similar to that of the general population. The disturbing part was that men whose infertility was due specifically to azoospermia had a cancer risk that was nearly triple that of the general population. Even worse, within the group of men with azoospermia, those under age 30 had a cancer risk more than eight times higher than normal for men of that age.
Finally, to be even more certain that it wasn’t the cancer itself that was causing infertility, researchers removed from their analysis all men who were diagnosed with cancer up to three years after their semen tests, then recrunched the numbers. Again, the same risks were found.
Surprisingly, the risk was not limited only to testicular or prostate cancer. In fact, the types of cancers seen in men with azoospermia also included cancers of the stomach, brain and small intestine, as well as melanoma and lymphoma.
Explanation: DNA probably holds the key to the azoospermia/cancer connection. Studies have shown high rates of defects in DNA repair mechanisms and abnormalities in life cycles of cells among men with azoospermia—and these same genetic defects may increase the likelihood of cancer, researchers suspect.
Self-defense: Men with azoospermia have approximately the same cancer risk as their peers who are about a decade older, researchers estimate. If you have azoospermia, it would be wise to talk with your doctor about the healthful diet and lifestyle choices that can help reduce your cancer risk…about cancer warning signs to watch for…and about when you should start getting regular cancer screenings.
Joyful news: If you and your partner want to have children, also ask your doctor about surgical testicular sperm extraction followed by in vitro fertilization. According to the study researchers, this type of assisted reproductive technology can help about half of azoospermic men to father children.