Infertility May Hike Testis Cancer Risk
WASHINGTON, D.C.—Men with a history of infertility may be at increased risk of testicular cancer, according to the largest study to date looking at this issue.
Findings suggest that infertility and testis cancer may share common etiologic factors.
Using the largest multi-institutional cohort of men presenting for infertility care available to date, researchers at the University of California in San Francisco (UCSF) examined the association between male infertility and the subsequent development of testicular cancer.
The research team at the university studied couples who had been evaluated for infertility at 15 California infertility centers. They linked the male partners to the California Cancer Registry (CCR), the cumulative Surveillance Epidemiology and End Results (SEER) registry for the state of California.
For this investigation, the researchers excluded testis cancer cases diagnosed after the diagnosis of infertility. They compared the incidence of testicular cancer in the entire cohort of 51,000 couples to the incidence in an age-matched sample of men from the general population using the SEER Program of the National Cancer Institute.
The researchers identified 43,404 male partners of infertile couples in the cohort for linkage to the CCR and 44 post-infertility cases of histologically confirmed testicular cancer. The mean age at the time of infertility evaluation was 36 years for the men who did not develop cancer and 33 years for the 44 men who were subsequently diagnosed with the malignancy.
Testicular cancer was 1.7 times more likely to develop in male partners of infertile couples than men in the general population, even if the infertility was not necessarily due to male factors. The risk was relatively constant across all age strata. The cancer risk was 3.5 times greater in men with known male factor infertility.
“We believe that there are underlying exposures or genetics that are contributing to both diseases. We don't think that infertility treatment is contributing to testis cancer development,” noted Thomas Walsh, MD, clinical instructor of urology at UCSF.
Dr. Walsh, who presented the study findings here at the 2007 annual meeting of the American Society for Reproductive Medicine, said the new data support previous findings by other researchers and points to a new area of research that needs to investigate this commonality.
Co-investigator Paul Turek, MD, professor of urology at UCSF, said this study is important because for the first time it confirms in the United States what has previously been found in Europe. He said it also points to some common denominator that underlies infertility and testis cancer.
“It may be that infertility or an abnormal semen analysis is an early marker for future problems in these men. Maybe it is an early sign of a problem,” Dr. Turek told Renal & Urology News. “So, I think urologists need to let these men know they are at higher risk for cancer and that they need to do testicular self-exams. These men should be examining themselves once month similar to women with breast exams.”