24% higher cancer rates found in military pilots, ground crews, Pentagon study finds

WASHINGTON — A Pentagon study has found high rates of cancer among military pilots and for the first time has shown that ground crews who fuel, maintain and launch those aircraft are also getting sick.

The data had long been sought by retired military aviators, who have raised alarms for years about the number of air and ground crew members they knew who had cancer. They were told that earlier military studies had found they weren’t at greater risk than the general population.

Yet, in its yearlong study of almost 900,000 service members who flew on or worked on military aircraft between 1992 and 2017, the Pentagon found that air crew members had an 87% higher rate of melanoma and a 39% higher rate of thyroid cancer and that men had a 16% higher rate of prostate cancer and women a 16% higher rate of breast cancer. Overall, the air crews had a 24% higher rate of cancer of all types.

The study showed ground crews had a 19% higher rate of brain and nervous system cancers, a 15% higher rate of thyroid cancer and a 9% higher rate of kidney or renal cancers, and women had a 7% higher rate of breast cancer. The overall rate for cancers of all types was 3% higher.

Ground and air crews both had far lower rates of lung cancer, though, and air crews also had lower rates of bladder and colon cancers.

The data compared the service members with the general U.S. population, adjusting for age, sex and race.

The Pentagon said the new study was one of the largest and most comprehensive that’s been done. An earlier study looked at just Air Force pilots and found some higher rates of cancer, but this one looked across all services and at both air and ground crews.

Even with the wider approach, the Pentagon cautioned that the number of cancer cases is likely to be even higher because of gaps in the data, which it said it would work to remedy.

The study “proves that it’s well past time for leaders and policy makers to move from skepticism to belief and active assistance,” said retired Air Force Col. Vince Alcazar, a member of the Red River Valley Fighter Pilots Association, which had lobbied the Pentagon and Congress for help. Alcazar serves on the association’s medical issues committee.

The study was required by Congress in the 2021 defense bill. Because higher rates were found, the Pentagon has to conduct an even bigger review to try to understand why the crews are getting sick.

The Pentagon said this study “does not imply that military service in air crew or ground crew occupations causes cancer because there are multiple potential confounding factors that could not be controlled for in this analysis,” such as family histories, smoking and alcohol use.

But aviation crews have long been asking the Pentagon to look closely at some of the environmental factors they’re exposed to, such as jet fuels and solvents used to clean and maintain jet parts, sensors and their power sources in aircraft nose cones as well as massive radar systems on the decks of ships they land on.

When Navy Capt. Jim Seaman would come home from a deployment aboard an aircraft carrier, his gear would reek of jet fuel, according to his widow Betty Seaman. Seaman, who was a Navy A-6 Intruder pilot. died in 2018 at 61 of lung cancer.

Betty Seaman said she still has his gear stored — and that it still smells of fuel. Seaman said crews would talk about how even the ship’s water systems would smell of fuel.

The study found that, when crew members were diagnosed with cancer, they were more likely to survive than members of the general population, which the study suggested was because they were diagnosed earlier due to regular required medical checkups and were more likely to be in better health because of their military fitness requirements.

The Pentagon acknowledged that the study had gaps that likely led to an undercount of cancer cases. The military heath system database used in the study didn’t have reliable cancer data until 1990, so it might not have included pilots who flew early-generation jets in previous decades.

The study’s authors also noted that it didn’t include cancer data from the federal Department of Veterans Affairs or state cancer registries, which means it didn’t include cases of crew members who got sick after leaving the military medical system.

A second phase of the study will try to isolate causes and determine the type of aircraft and locations where diagnosed crews served.

After her husband got sick, Betty Seaman asked whether he’d have chosen differently had he known his service might be linked to his cancer: “He, without hesitation, said, ‘I would have still done it.’ ”