SILVER SPRING, MD — Although rates of breast cancer among U.S. female active-duty servicemembers have fluctuated slightly during the past 12 years, they also have remained fairly stable, according to a new study published in Medical Surveillance Monthly Report, a peer-reviewed journal on illnesses and diseases affecting service members from the Armed Forces Health Surveillance Center (AFHSC).1
During the study period from 2000 to 2012, 1,092 active component military women were diagnosed with breast cancer for a crude incident ratio of 40.6 per 100,000 person-years (p-yrs). Slightly more than 22% of those were ductal cinoma in situ (DCIS) cases.
The surveillance population included all women who served in the active component of the U.S. Armed Forces at any time during the surveillance period. All data used to determine incident cancer cases were derived from records routinely maintained in the Defense Medical Surveillance System (DMSS).
The year with the lowest annual incidence rate was 2006, with 28.6 per 100,000 p-yrs, while the highest was 2001, with an annual incidence rate 53.6 per 100,000 p-yrs.
“The most important observations from this study of active component servicewomen were [that] annual incidence rates of breast cancer have fluctuated up and down from year to year during the last 13 years but there has been no discernible longterm trend upward or downward,” said Army Col. William Corr, the deputy director of AFHSC’s division of Epidemiology and Analysis. “In addition, approximately 22% of all breast cancers diagnosed during the period were ductal carcinoma in situ (DCIS), the least invasive form of breast cancer.”
Crude incidence rates of DCIS fluctuated less dramatically during the period, averaging 9.1 per 100,000 p-yrs. An incident rate of 11 cases per 100,000 p-yrs was higher in 2012 than in 2000, where rates were 8 cases per 100,000 p-yrs, however. DCIS is less common than invasive breast cancer, but diagnosis rates have soared with widespread adoption of mammography.
The average incidence rate for invasive breast cancer was 31.5 per 100,000 p-yrs, with the rate being slightly lower at 32.1 in 2012 compared with 33.8 in 2000.
According to the report, older age was the strongest demographic correlate of increased risk of a breast cancer. In fact, the highest rates of diagnoses were among those older than 40 years, with DCIS more than four times common in the older group than in those 35 to 39 yearsold.
Crude incidence rates of both DCIS and invasive breast cancer were lower among members of the Marine Corps than the other military services, and servicemembers in healthcare occupations were more likely to have incident breast cancer rates.
Interestingly, black, non-Hispanic women had higher overall crude incidence rates of all types of breast cancer (rate: 49.0 per 100,000 p-yrs) than women in any other race-ethnicity category. Among civilians in the United States, the average annual breast cancer rate is highest in white, non-Hispanic women, followed by African-American women.
The authors suggested a factor contributing to the difference might be “the prevalence of screening mammography by race/ethnicity among female military members.”
The article also noted that women in the military are subject to relatively intensive medical screening, so cancers may be detected earlier in their clinical courses in active military than in civilian populations, making rates appear higher in those age groups. On the other hand, early detection and treatment of cancer can decrease mortality compared with civilians.
1Armed Forces Health Surveillance Center (AFHSC). Incident diagnoses of breast cancer, active component service women, U.S. Armed Forces, 2000-2012. MSMR. 2013