Cancer Incidence and Mortality Among Fighter Aviators in the United States Air Force

Exposures and Bladder Cancer Risk Among Military Veterans: A Systematic Review and Meta-analysis

OBJECTIVE

To investigate potential carcinogenic exposures in military personnel that are implicated in the development of bladder cancer.

METHODS

This systematic review aimed to evaluate the association between specific military exposures and bladder cancer risk among veterans. PubMed, Scopus, and Ovid MEDLINE databases were searched in December 2023 for relevant articles. Inclusion criteria comprised retrospective cohort studies, reviews, and observational studies documenting bladder cancer incidence among military populations exposed to specific agents. A total of 25 studies, involving 4,320,262 patients, met the inclusion criteria. Data extraction followed PRISMA guidelines, and a random-effects model was used for data synthesis.

RESULTS

The meta-analysis revealed significant associations between exposure to Agent Orange (HR 1.17 [95% CI: 1.01-1.36], P < .00001) and depleted uranium (HR 2.13 [95% CI: 1.31-3.48], P = .002) with increased bladder cancer risk among veterans. Contaminated drinking water showed a trend towards increased risk (HR 1.25 [95% CI: 0.97-1.61], P = .08).

CONCLUSION

The findings suggest a possible association between specific military exposures and heightened bladder cancer risk among veterans, emphasizing the necessity for targeted screening protocols and preventive measures. Further research is essential to identify specific carcinogenic agents and prevalence of exposures among veterans, enabling more effective prevention and management strategies.

Incidence rates of bladder and kidney cancers among US military servicemen: comparison with the rates in the general US population

OBJECTIVE

The military population may differ from the general population in factors related to bladder and kidney cancers. However, incidence rates of these cancers have not been systematically compared between the two populations. This study compared incidence rates of bladder and kidney cancers between active-duty servicemen and men in the general US population.

METHODS

Data were obtained from the Department of Defense's Automated Central Tumor Registry (ACTUR) and the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) database. Included were 18-59-year-old active-duty servicemen in ACTUR and men in SEER who were diagnosed with malignant bladder and kidney cancers from 1990 to 2013. Age-adjusted rates, incidence rate ratios (IRR) and their 95% confidence intervals (95% CI) were compared between the two populations by age, race, and cancer stage.

RESULTS

Incidence rates were lower in ACTUR than SEER for bladder cancer overall (IRR = 0.55, 95% CI, 0.48-0.62) and by age (except ages 50-59), race, and tumor stage. For ages 50-59, rates did not differ between the populations. Kidney cancer incidence rates were lower in the military for younger groups and Black men, but higher for ages 50-59.

CONCLUSION

Lower bladder and kidney cancer incidence in ACTUR, notably in younger men, may be primarily associated with better health and healthcare access. The lack of differences in bladder or kidney cancer incidence among 50-59-year-old men between the populations might result from multifactorial effects, such as the possible effects of cumulative military-related exposures offset by healthier status and better medical care.

Cancer risk among air transportation industry workers in Korea: a national health registry-based study

BACKGROUND

Flight attendants face various risk factors in their working environments, particularly occupational exposure to cosmic radiation. This study aimed to assess cancer risk among air transportation industry workers, including flight attendants, in Korea by constructing a cohort using national health registry-based data and analyzing cancer incidence risk.

METHODS

We used the Korea National Health Insurance Service database from 2002 to 2021 to construct a cohort of 37,011 workers in the air transportation industry. Cancer incidence was defined using the tenth version of the International Classification of Diseases. We calculated the age- and sex-specific standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) by applying the cancer incidence rate of the general population between 2002 and 2019.

RESULTS

Approximately 5% of the cohort developed cancer. Overall, the cancer incidence in the cohort was similar to or lower than that of the general population, with the SIRs for all cancers being lower. However, significantly higher SIRs were observed for nasopharyngeal cancer (SIR, 3.21; 95% CI, 1.71-5.48) and non-Hodgkin lymphoma (SIR, 1.57; 95% CI, 1.02-2.32) in male workers and breast and genital cancer (SIR, 1.51; 95% CI, 1.34-1.70) and thyroid cancer (SIR, 1.25; 95% CI, 1.05-1.47) in female workers.

CONCLUSIONS

The lower overall cancer incidence among air transportation industry workers observed in this study could indicate the "healthy worker effect"; however, the incidences of certain cancers were higher than those in the general population. Given that these workers are exposed to multiple occupational and lifestyle-related risk factors, including cosmic radiation, further studies are necessary to determine radiation-induced cancer risk while considering potential confounding factors.

U.S. Army mortality surveillance in active duty soldiers, 2014-2019

Mortality surveillance is an important activity for capturing information on a population's health. This retrospective surveillance analysis utilizes administrative data sources to describe active duty U.S. Army soldiers who died from 2014 to 2019, and calculate mortality rates, assess trends by category of death, and identify leading causes of death within subpopulations. During the surveillance period, 2,530 soldier deaths were reported. The highest crude mortality rates observed during the 6-year surveillance period were for deaths by suicide, followed by accidental (i.e., unintentional injury) deaths. The crude mortality rates for natural deaths decreased significantly over the 6-year period, by an average of 6% annually. The leading causes of death were suicide by gunshot wound, motor vehicle accidents, suicide by hanging, neoplasms, and cardiovascular events. Significant differences were observed in the leading causes of death in relation to demographic characteristics, which has important implications for the development of focused educational campaigns to improve health behaviors and safe driving habits. Current public health programs to prevent suicide should be evaluated, with new approaches for firearm safety considered.

Military occupation and testicular germ cell tumour risk among US Air Force servicemen

OBJECTIVES

Testicular germ cell tumours (TGCTs) are the most commonly diagnosed malignancy among active duty US military servicemen. Occupational risk factors may play a role in TGCT aetiology, although the evidence is inconclusive. The objective of our study was to investigate associations between military occupations and TGCT risk among US Air Force (USAF) servicemen.

METHODS

This nested case-control study among active duty USAF servicemen obtained information on military occupations for 530 histologically confirmed TGCT cases diagnosed during 1990-2018 and 530 individually matched controls. We determined military occupations using Air Force Specialty Codes ascertained at two time points: at case diagnosis and at a time point on average 6 years earlier. We computed adjusted ORs and 95% CIs from conditional logistic regression models to evaluate associations between occupations and TGCT risk.

RESULTS

The mean age at TGCT diagnosis was 30 years. Increased TGCT risk was observed for pilots (OR=2.84, 95% CI: 1.20-6.74) and servicemen with aircraft maintenance jobs (OR=1.85, 95% CI: 1.03-3.31) who held those jobs at both time points. Fighter pilots (n=18) and servicemen with firefighting jobs (n=18) at the time of case diagnosis had suggestively elevated TGCT odds (OR=2.73, 95% CI: 0.96-7.72 and OR=1.94, 95% CI: 0.72-5.20, respectively).

CONCLUSIONS

In this matched, nested case-control study of young active duty USAF servicemen, we found that pilots and men with aircraft maintenance jobs had elevated TGCT risk. Further research is needed to elucidate specific occupational exposures underlying these associations.

Circadian Rhythm Disruption as a Contributor to Racial Disparities in Prostate Cancer

In the United States, African American (AA) men have a 2.4 times higher mortality rate due to prostate cancer than White men. The multifactorial causes of the racial disparities in prostate cancer involve various social determinants of health, socioeconomic status, and access to healthcare. However, emerging evidence also suggests that circadian rhythm disruption (CRD) contributes to prostate cancer, and AA men may be more susceptible to developing CRDs. Circadian rhythms play a significant role in metabolism, hormone secretion, and sleep/wake cycles. Disruption in these circadian rhythms can be caused by airplane travel/jetlag, night shift work, exposure to light, and neighborhood noise levels, which can contribute to sleep disorders and chronic conditions such as obesity, diabetes, cardiovascular disease, and depression. The drivers of the racial disparities in CRD include night shift work, racial discrimination, elevated stress, and residing in poor neighborhoods characterized by high noise pollution. Given the increased vulnerability of AA men to CRDs, and the role that CRDs play in prostate cancer, elucidating the clock-related prostate cancer pathways and their behavior and environmental covariates may be critical to better understanding and reducing the racial disparities in prostate cancer.