Early and Repeated Exposure to Diagnostic Imaging Increases Testicular Cancer Risk

A new study from researchers at Penn Medicine suggests that early and repeated exposure to diagnostic imaging, such as X-rays and computerized tomography (CT) scans, is linked to increased risk for testicular germ cell cancer.

“The steady rise in testicular germ cell tumor (TGCT) cases over the past three or four decades suggests there is an environmental exposure risk at play, but no definitive risk factor has ever been identified,” senior author Katherine L. Nathanson, MD, deputy director of Penn’s Abramson Cancer Center, said in a press release. “Our data suggests that the increased use of diagnostic radiation below the waist in men over that same time may contribute to the increase in incidence.”

The researchers conducted an observational study of 1,246 men between ages 18-55 with and without testicular cancer. Participants completed a questionnaire regarding known and presumptive risk factors for TGCT and diagnostic imaging during their lifetime, including location of scans and number of exposures. Tumor samples were also collected.

After adjusting for known testicular cancer risks, such as family history, race, and other factors, the investigators found a 59% increased risk increased risk of TGCT among participants who reported at least three exposures to X-ray and CT below the waist when compared to men with no such exposure. Risk was also higher for those exposed to diagnostic radiation during the first 10 years of their life, compared to men who were first exposed at age 18 or later.

The risk was also elevated for those exposed to diagnostic radiation during the first decade of their life, compared to those first exposed at age 18 years or later.

“If our results are validated, efforts to reduce medically unnecessary and avoidable testicular exposure should be considered, in part through efforts to reduce radiation dose and optimize shielding practices when appropriate,” wrote the authors.

This study was published in PLOS ONE.