Analysis of Brain Cancer Risk Among AFSOC and Conventional C-130 Aircrew

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA522424&Location=U2&doc=GetTRDoc.pdf

Analysis of Brain Cancer Risk Among AFSOC and Conventional C-130 Aircrew

AFRL-SA-BR-TR-2010-0005

Brett R. Nishikawa, Maj, USAF, MC, FS
Paul A. Sjoberg, Col, USAF, BSC

Between 2006 and 2009, seven cases of primary brain cancer, including two deaths, were reported among Air Force Special Operations Command (AFSOC) C-130 crewmembers. Of particular concern was crew status on the MC-130 models (particularly the MC-130P) as an apparent common factor among the cases. This prompted AFSOC to request that the USAF Epidemiology Consult Service evaluate the potential risk posed by C-130s or by modified AFSOC-specific C-130s on the development of brain cancer. Brain cancer is a very rare event and has few known risk factors. The only known environmental risk for developing brain cancer is exposure to extremely high doses of ionizing radiation, as seen with atomic bomb detonations and with extreme doses of therapeutic radiation used to treat childhood cancers several decades ago. The vast majority of brain cancers are random occurrences with no identifiable cause. Some earlier studies suggest a higher incidence of brain cancer among career aviators, although more recent studies have not found an increased incidence. Studies of military aviators specifically have not found an increase in brain cancer attributable to flying. The cases reported from AFSOC appear to be related to chance and not to any particular exposure risk. Population-based evaluation of tumor registry and mortality data revealed no increased risk for brain cancer associated with flying or with C-130 models specifically. Formal assessment of nonionizing radiation exposure levels in selected C-130 model cockpits may be considered, although the results of such an evaluation would not alter the conclusions of this investigation.