Agent Orange Exposure Linked to Higher Prostate Cancer Risk, Mortality Among US Veterans

Key Clinical Summary

• A nationwide US Veterans Affairs (VA) cohort study of 2.6 million Vietnam veterans found higher risks of prostate cancer and mortality linked to Agent Orange exposure (AOE).
• Veterans with AOE had increased risks for de novo metastasis, metastatic castration-resistant prostate cancer, and prostate cancer–specific mortality.
• While causality cannot be confirmed, AOE may serve as a prognostic marker for worse outcomes in VA care.

Introduction

A large VA study published in Cancer evaluated whether AOE during the Vietnam War is associated with prostate cancer (PCa) incidence and adverse outcomes. The nationwide cohort analysis found that veterans with presumptive AOE experienced higher risks of prostate cancer, metastasis, and death compared with unexposed veterans.

Study Findings

In this VA-wide study, researchers analyzed data from nearly 2.6 million Vietnam veterans who received VA health care between 2005 and 2020. Participants were aged 17 to 25 during military service (1962-1971) and were stratified by VA-assigned presumptive AOE.

Of these, 779 472 veterans (30%) were classified as exposed to Agent Orange. After follow-up through September 2023, the analysis revealed significantly elevated risks across multiple outcomes. Compared with unexposed veterans, those with AOE had:

• 15% higher risk of prostate cancer (adjusted hazard ratio [aHR], 1.15; 95% CI, 1.15-1.16).
• 17% higher risk for de novo metastasis, any metastasis, and metastatic castration-resistant PCa (aHR, 1.17 for each; 95% CI, 1.16-1.17).
• 41% higher all-cause mortality (aHR, 1.41; 95% CI, 1.41-1.42).
• 17% higher prostate cancer–specific mortality (aHR, 1.17; 95% CI, 1.16-1.17).

Sensitivity analyses suggested that selection bias could not be ruled out as a factor contributing to the observed associations. Nonetheless, the large sample size provided statistical power to evaluate clinically significant endpoints such as metastatic disease and mortality.

Clinical Implications

These findings reinforce ongoing concerns about the long-term health consequences of Agent Orange exposure among Vietnam-era veterans. Although causation remains uncertain, clinicians caring for veterans should recognize AOE as a potential prognostic indicator for adverse prostate cancer outcomes.

The study highlights the need for enhanced prostate cancer surveillance and early detection strategies in AOE-exposed veterans. Tailored screening and risk-based management approaches within the VA system may help mitigate the observed excess in cancer-related morbidity and mortality. Moreover, the research underscores the broader implications of environmental exposures during military service and their relevance to long-term veteran health care planning.

Conclusion

Presumptive Agent Orange exposure among Vietnam veterans was associated with higher prostate cancer incidence, mortality, and adverse clinical outcomes. While bias may contribute to these associations, AOE remains an important consideration for risk stratification and long-term care in the VA population.

Reference

Green-Lott AY, Wadhwa A, Bailey AV, et al. Prostate cancer incidence and outcomes among Vietnam veterans receiving care in the Veterans Health Administration. Cancer. 2025;131(15):e70007. doi: 10.1002/cncr.70007