Infertile Men Have Higher Cancer Risk

Men who have no sperm have a higher risk of developing cancer than other males, researchers from Stanford University School of Medicine reported in Fertility and Sterility (June 20th, 2013 issue).

When a man has no measurable level of sperm in his semen he has azoospermia, he is azoospermic. Fertility experts estimate that approximately 1% of men are azoospermic, and that about 20% of male infertility problems are because of azoospermia. According to the study, men who are diagnosed with azoospermia before thirty years of age are eight times more likely to develop cancer, compared to other men. Lead author Michael Eisenberg, MD, PhD, said "An azoospermic man's risk for developing cancer is similar to that for a typical man 10 years older." Approximately 15% (4 million) of all men aged from 15 to 45 in the USA are infertile. About 600,000 of them are azoospermic - 1% of the male population of the country. The researchers believe that infertility could well be a bellwether for a male's overall health.

While previous studies had linked male infertility to testicular cancer risk, this latest one has found an association between male infertility and other cancers too. Eisenberg and team gathered and analyzed data from the Baylor College of Medicine in Houston and the Texas Cancer Registry. This included 2,238 men who were seen or treated at a Baylor andrology clinic between 1989 and 2009 - they were all infertile. 451 of them had azoospermia and 1,787 didn't. The authors added that there were no otherwise apparent initial differences between those with and without azoospermia.

Azzospermia has two main causes: 1. Obstructive azoospermia - there is a blockage which stops the flow of otherwise plentiful and 2. Healthy sperm in the testes from reaching the ejaculate Non-obstructive azoospermia - the testes did not produce enough (or any) sperm to reach the ejaculate. After screening about 25% of men with no measurable sperm, the researchers discovered that most of them suffered from non-obstructive azoospermia, probably due to some kind of genetic defect. One quarter of all the genes in the human genome play some kind of part in reproduction. This means that there are a huge number of genetic ways a man can be azoospermic. The men underwent a semen analysis and were followed for 6.7 years (average) to find out how many of them ended up in the Texas Cancer registry. Fortunately for the researchers, most Texans tend to stay in their state long term. The team then compared their incidence of diagnosed cancer with age-adjusted cancer-diagnosis statistics of Texas males overall.