b'Traumatic Brain Injury Associated With Increased Risk of Brain CancerThe risk of adverse long-term outcomes, including cardiovascular disease, dementia, epilepsy and mental health issues, is well known for servicemembers and veterans suffering from traumatic brain injury (TBI).A new study of post-9/11 veterans, however, has raised the specterthat TBI also might make patients more vulnerable to brain cancer. By Mary Anne DunkinBETHESDA,MDTraumaticbraininjury(TBI)goal, he said.has been linked to poor long-term outcomes in theUsing data from 1,919,740 veterans with a median veteranpopulation,includingcardiovasculardis- follow-up of 7.2 years, the researchers classified brain ease, dementia, epilepsy and mental health issues. Acancer on the basis of administrative codes and death new study of post-9/11 veterans provides evidence ofcodes and then conducted a Fine and Gray analysis, yet another concerning effect of TBIan increased,which basically gives us the risk of developing a although still low, risk of brain cancer.brain cancer while adjusting for the competing end-LedbyIanJ.Stewart,MD,oftheUniformedpoint of death, Stewart said. TBI severity was cat-Services University of Health Sciences, the study isegorized as mild, moderate/severe and penetrating. 1the first to examine the potential association betweenThe cohort included 449,880 individuals with TBITBI and brain cancer in a veteran cohort.385,848mild;46,859moderate/severe;and17,173 Stewart,whoseresearchfocuseslargelythepenetrating. Brain cancer occurred in 318 individuals effectsofcombatinjuryandtrauma,becamewithout TBI (0.02%), 80 with mild TBI (0.02%), 17 interested in a possible connection between TBIwith moderate/severe TBI (0.04%), and 10 or fewer andsubsequentbraincancerwhenacolleague,with penetrating TBI (0.06%). MichaelDore,MD,toldhimthattwoofhis[After adjustment,] we found that mild TBI was patients with multiple TBIs had been diagnosednotassociatedwithsubsequentbraincancer,but with glioblastoma. While glioblastoma is the mostboth moderate and severe TBI and also penetrating common form of brain cancer, it is still quite rare,TBI were associated with subsequent brain cancer, affecting 3.21 per 100,000 population. Stewart said. Given how rare that diagnosis is, he thought it wasWhile the new study was the first to establish a link quite a coincidence that that they both happened to getbetween TBI and brain cancer in post-9/11 veterans, that brain cancer, Stewart told U.S. Medicine. HeStewart said a link between TBI and subsequent brain wanted to see if we had any data and could look at thiscancer has been recognized as biologically plausible in a systematic fashion. for some time. He cited a 1978 study of a rat model Asitsohappenedtheydidintheformofthefor neural tumors found that animals exposed to a Long-TermImpactofMilitary-RelevantBraincerebral stab wound were more likely to develop glio-Injury Consortium-Chronic Effects of Neurotraumamas compared with uninjured control animals. 2Consortium (LIMBIC-CENC) database, Stewart said.More recently, researchers who performed single-The LIMBIC-CENC is a comprehensive research net- cell RNA sequencing on glioblastoma stem cells from work for DoD and VA with the goal of looking at TBI26 individuals found that these cells mapped to states and the outcomes after TBI, so examining a connec- reminiscent of neural development and the inflamma-tion between TBI and brain cancer fit nicely into thattory wound response. Based on these results, that 48'