Veterans with higher traumatic brain injury predisposed to subsequent brain cancer

Veterans of Iraq and Afghanistan who sustained moderate/severe and penetrating traumatic brain injury (TBI) are at increased risk of developing brain cancer, as shown in a study.

For the retrospective cohort study, researchers looked at 1,919,740 veterans (median age at index date 31 years, 80.25 percent men, 63.11 percent non-Hispanic White) from the Long-Term Impact of Military-Relevant Brain Injury Consortium–Chronic Effects of Neurotrauma Consortium. The main exposure of interest was the severity of TBI, which was categorized as mild, moderate or severe, and penetrating.

Over a median follow-up of 7.2 years, brain cancer was diagnosed in 318 participants without TBI (0.02 percent), 80 with mild TBI (0.02 percent), 17 with moderate/severe TBI (0.04 percent), and 10 or fewer with penetrating TBI (≤0.06 percent). The respective crude incidence rates of brain cancer were 3.06, 2.85, 4.88, and 10.34 per 100,000 person-years (p<0.001).

Multivariable analysis showed that moderate/severe TBI was associated with an elevated risk of brain cancer (adjusted hazard ratio [AHR], 1.90, 95 percent confidence interval [CI], 1.16–3.12). The same was true for penetrating TBI (AHR, 3.33, 95 percent CI, 1.71–6.49) but not mild TBI (AHR, 1.14, 95 percent CI, 0.88–1.47).

The findings highlight the importance of developing screening protocol and better identify individuals at risk of subsequent brain cancer.