Men with no sperm are more likely to develop cancer than the general population.
Men, classified as azoospermic, suffer from a condition causing an absence of sperm in the ejaculate. Men who are diagnosed with azoospermia before the age of 30 are eight times more likely to develop cancer, according to a Stanford School of Medicine press release.
"An azoospermic man's risk for developing cancer is similar to that for a typical man 10 years older," said Michael Eisenberg MD, PhD, assistant professor of urology at the medical school and director of male reproductive medicine and surgery at Stanford Hospital and Clinics, who led the study.
Men who are azoospermic either experience a blockage in the testes or simply don't produce enough sperm to ejaculate. The majority of affected men have the latter.
About 15 percent of men between the ages of 15 to 45 are infertile in the U.S. Only about one percent of these men are actually azoospermic.
"There is evidence that infertility may be a barometer for men's overall health," Eisenberg said, "and a few studies have found an association of male infertility with testicular cancer."
According to Eisenberg, the higher cancer risk extends outside of only testicular cancers. The study looked at 2,238 men who were seen at the same clinic between 1989 and 2009. Out of the patients who participated in the study, 451 were azoospermic, which was the only observed difference between the two groups.
After an initial sperm analysis the men were observed for about seven years, over a five-year period 29 of the study participants developed cancer. This proved the infertile men to be 1.7 times more likely to develop cancer than the general population.
The majority of the men who developed cancer were azoospermic, they were found to be three times more likely to develop cancer than the average population. The azoospermic men developed not just testicular cancer, but stomach tumors, melanoma, lymphoma and cancer of the small intestines.
Researchers concluded that genetics may be to blame for the correlation between the condition and cancer.
