WASHINGTON, DC—While active duty servicemembers have lower rates of some cancers compared to civilians, they have double the rate of prostate cancer and higher rates of breast cancer, according to a new study.

In the June issue of Cancer Epidemiology Biomarkers and Prevention, Uniformed Services University of the Health Sciences (USUHS) investigator Kangmin Zhu, MD, PhD and his fellow researchers noted that active duty servicemembers might differ from the US population in their exposure to cancer risk factors and access to medical care. However, it is not known whether cancer incidence rates differ for the two populations. Therefore, researchers compared the incidence patterns of six cancers among active duty personnel and the general population using data from the following: DoD’s Automated Central Tumor Registry (ACTUR), and the nine cancer registries from NCI’s Surveillance Epidemiology and End Results (SEER). Study parameters included data from 1990 to 2004 for persons between the ages of 20 and 59.

While the study found that military personnel had lower incidence rates of colorectal, lung, and cervical cancers than the general population, it also revealed that prostate cancer rates in the military were twice those in the general population, and breast cancer rates were 20% to 40% higher. “Incidence rates were significantly lower in the military population for colorectal cancer in white men, lung cancer in white and black men and white women, and cervical cancer in black women. In contrast, incidence rates of breast and prostate cancers were significantly higher in the military among whites and blacks. Although the numbers of diagnoses among military personnel were relatively small for temporal trend analysis, we found a more prominent increase in prostate cancer in ACTUR than in SEER,” the study stated.

Higher Breast and Prostate Cancer Rates in Military

The June study by USUHS revealed that breast and prostate cancer rates for military personnel were “significantly higher” than the general population. This data may be attributable to more frequent screening for these cancers in military populations who receive free medical care. Consequently, the study speculated, servicemembers and their families may visit their primary care physicians more frequently than the general population.

Kangmin Zhu noted that many factors play a role in a given population’s increased cancer rates. In the case of prostate cancer, the authors suggested that servicemembers are more likely to be exposed to depleted uranium. Depleted uranium, the material used in armor penetrators, “has been suggested to increase the risk for prostate cancer,” according to the study. In the case of breast cancer, women in the military may be more likely to use oral contraceptives, which have been linked to increased risk of breast cancer. They may also be engaged in industrial jobs that expose them to chemicals related to breast cancer.

On the other hand, certain cancers were found to occur less frequently in military populations. Lung cancer in particular was less common among white and black men and white women in the military than their counterparts in the civilian population. Study authors called this an “unanticipated finding” due to the prevalence of smoking, the biggest risk factor for lung cancer, in the military. Junior enlisted military personnel especially are more likely to smoke than the general population. One explanation for this unusual trend may be that that the majority of civilians start smoking in their teens, while servicemembers often start as adults. In addition, it is possible that servicemembers smoke fewer cigarettes than their civilian counterparts; the frequency of smoking in the military decreased sharply from 1980 to 1998.

Ultimately, the study’s authors concluded that understanding cancer incidence patterns in the two populations, military and nonmilitary, The full text of the study can be found at http://cebp.aacrjournals.org/cgi/reprint/18/6/1740.

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