In a new study, researchers have found that black and white women aged 75–84 years who received a regular annual mammogram had reduced 10-year breast cancer mortality compared with women who received biannual mammograms, or irregular mammograms. The results of the study were published in the American Journal of Medicine.
Breast cancer is the second most common cancer in women. Among individuals affected by breast cancer, one in 25 will die of the disease. There are existing data demonstrating the benefits of mammography screening in women up to the age of 74 years, but there is a lack of data available for women above this age, especially in minorities.
In 2010, 41% of breast cancer deaths occurred in women between the ages of 65–84 years. The American Cancer Society and the United States Preventive Services Task Force recommend regular mammography for women between the ages of 65 to 74 years.
The team, led by Charles H Hennekens from Florida Atlantic University (FL, USA), utilized the Surveillance, Epidemiology, and End Results program file linked to the Medicare administrative claims file to track screening mammography use between 1995 and 2009 from 64,384 non-Hispanic women of whom 4886 were black and 59,498 were white.
The researchers also studied mortality differences between elderly women who self-selected for regular annual or biannual mammography screening. Medicare coverage of the general population begins at age 65; as such the lower age limit of the study was 69 years.
The researchers defined three mutually exclusive categories: no or irregular mammography; biennial mammography; and annual mammography. Hispanic women were excluded from the study because Hispanic white women have lower mortality rates compared with non-Hispanics. The team also analyzed socioeconomic status, including data on household income, poverty level and school education.
Other key findings of the study included that white women who died were more often older, had later-stage disease and had higher socioeconomic status. They were also more likely to have received chemotherapy rather than surgery or radiation.
Similar results were also observed in black women. Women between the ages of 69–84 years receiving regular annual mammography during the 4 years preceding breast cancer diagnosis had lower 5-year and 10-year risks of mortality than women with no or irregular screening, regardless of race. Ten-year risks were more than three-times greater in white women and more than two-times greater in black women aged 69–84 years with no or irregular screening compared with annual screening.
The researchers acknowledge that additional research is needed, but in the future it is possible that the use of regular claims-based surveillance for mammography as a source of data may offer some advantages over self-reports.