PORTLAND, OR — Agent Orange exposure might have had more effect than previously assumed on development of head and neck cancers, according to a recent study.

A report in the Oral Oncology journal described how self-reported Agent Orange exposure was linked with increased risks of oropharyngeal, nasopharyngeal, laryngeal and thyroid cancers and predicted improved survival in upper aerodigestive tract cancer patients.1

“These findings broaden our understanding of the risks of Agent Orange exposure,” explained researchers from the Portland, OR, VA Health Care System and Oregon Health and Science University.

Noting that U.S. military personnel during the Vietnam War were potentially exposed to Agent Orange, a known carcinogen, the authors pointed out that the link between Agent Orange and head and neck cancers is largely unknown. Laryngeal cancer is currently the only subsite with sufficient evidence of an Agent Orange association, according to the report.

To provide more information, the study team sought to determine the relationship between Agent Orange exposure and the incidence of head and neck cancers in Vietnam era veterans. The study also looked at head and neck cancer survival and the relationship to Agent Orange.

To do that, researchers used the Veterans Affairs Corporate Data Warehouse, to identify Vietnam era veterans, their Agent Orange exposure status, limited demographic data, presence of head and neck cancer and survival data.

Of 8,877,971 Vietnam era veterans, 22% self-reported exposure to Agent Orange, and 54,717 had a diagnosis of head and neck cancer.

Results indicated that Agent Orange exposure significantly predicted upper aerodigestive tract carcinoma, with a relative risk (RR) of 1.10. On subsite analysis, Agent Orange exposure—as well as race, gender and substance use—was significantly associated with oropharyngeal (RR 1.16), nasopharyngeal (RR 1.22), laryngeal (1.11) and thyroid (1.24) cancers.

On the other hand, Agent Orange exposure also was associated with improved 10-year overall survival in upper aerodigestive tract cancer patients.


  1. Mowery A, Conlin M, Clayburgh D. Increased risk of head and neck cancer in Agent Orange exposed Vietnam Era veterans. Oral Oncol. 2020;100:104483. doi:10.1016/j.oraloncology.2019.104483