The Air Force has begun to look at whether there’s increased risk for prostate cancer among its fighter pilots.

The fighter pilot study was requested by Air Force Chief of Staff Gen. David Goldfein after he was contacted by concerned veterans service organizations in 2018, said a report obtained by McClatchy.

At the heart of the study was a question of whether extended exposure in the cockpit to radiation may be linked to increased risk of prostate cancer. The study said “pilots have greater environmental exposure to ultraviolet and ionizing radiation.”

The Air Force study found that fighter pilots are no likelier to develop prostate cancer than non-pilots. But the Air Force acknowledged the limitations of its review. One Air Force officer, who spoke on condition of anonymity, said the results the study age group was mostly airmen in their 20s to 40s and the review was based on active duty medical records, where prostate cancer may not yet have surfaced.

The fighter pilot group may also be less likely to use VA health care after leaving the military, because they often fly for commercial airlines and use the company’s health care.

The Air Force study reported 977 incidents of different types of cancer among the group it reviewed of 4,949 Air Force fighter pilots and 83,483 non-fighter pilot Air Force officers who were commissioned between 1986 and December 2006. An updated analysis in the same study included Veterans Health Administration data but it did not change the earlier findings.

Only two prostate cancer cases were found among the fighter pilots in that time frame, which the Air Force acknowledged may not reflect what veteran pilots are seeing.

The fighter pilot community “is a small, tight-knit sub-community,” the Air Force said. “Even if the cancer incidence rate in their community is the same as that of the broader (Air Force), it will not be experienced that way.”

The numbers in the VA health system tell a different story. McClatchy obtained data on how many cases of prostate cancer were diagnosed or treated in the VA health care system per fiscal year.

McClatchy found that the VA health care system reported 12,123 unique prostate cancer cases for Air Force veterans in fiscal year 2000 and 35,772 unique cases in fiscal year 2018, a 195% increase. A unique case refers to a veteran who is only counted once per fiscal year per cancer regardless of how many medical appointments were made that year to treat the cancer.

Across all military services, prostate cancer treatments doubled from 131,350 in fiscal year 2000 to 266,594 in fiscal year 2018.