Study Finds Risk of Testicular Cancer May Increase with Early and Repeated Diagnostic Imaging

Early and repeated exposure to diagnostic imaging, such as X-rays and CT scans, can increase the risk of testicular cancer, according to a new study published online in PLOS ONE.

Radiation’s ability to damage DNA makes it a risk factor in the development of cancer because the cells are unable to properly repair the damaged DNA, resulting in genetic mutations.

“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,” said 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 adjusted their data for known risks of testicular cancer, such as cryptorchidism and family history, race, age, and other factors. The data showed a statistically significant increase in the risk of testicular cancer among the participants reporting at least 3 exposures to X-rays, including a colon X-ray, and CT scan below the waist, compared to participants who did not receive exposure.

More, participants with 3 or more exposures to diagnostic imaging saw a 59% increase in their risk of testicular germ cell tumor compared to participants with no exposure to diagnostic imaging. Even further, the risk increased if participants were exposed to diagnostic imaging within the first 10 years of their life compared to those first exposed at age 18 or later.

The researchers conducted an observational study at Penn Medicine, with the study’s cohort including 1246 men between the ages of 18 and 55 years with and without testicular cancer. The participants were given questionnaires to fill out regarding information “known and presumptive risk factors for testicular cancer and diagnostic imaging during their lifetime.” Specifically, the information looked at location on the body and number of exposures of diagnostic imaging prior to diagnosis.

“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,” the authors wrote in their research.

Thus far, research on the role of diagnostic imaging, specifically CT scans, in the development of testicular cancer has been limited. Previous data has relied on occupational exposure rather than diagnostic imaging as a part of clinical care, with no recent studies evaluating the impact of diagnostic imaging.

For men between the ages of 15 and 45 years in the United States and Europe, testicular germ cell tumor is the most common form of cancer. The incidence rate is 6 of every 100,000 men today, with nearly 9500 cases being diagnosed by the end of 2020.

Reference:

Diagnostic Imaging May Increase Risk of Testicular Cancer. Philadelphia, Pennsylvania. Published November 9, 2020. https://www.newswise.com/articles/diagnostic-imaging-may-increase-risk-of-testicular-cancer?sc=sphr&xy=10019792. Accessed November 16, 2020.