Age-Related Breast Cancer Rates Differ Among Black, White Women, Study Finds
Black women have higher rates of early-onset breast cancer and lower rates of late-onset breast cancer than their white counterparts, according to a study published in the December Journal of the National Cancer Institute, Reuters reports. The study, led by William Anderson of the National Cancer Institute, was designed to verify differences in age-related breast cancer rates between black women and white women. The study involved data on 440,653 women with newly diagnosed invasive breast cancer, including 34,478 black women and 381,122 white women, that was obtained from the Surveillance, Epidemiology and End Results database from 1975 through 2004.
The study found that black women had higher rates of breast cancer that developed before age 40 than white women. Among participants who developed breast cancer after age 40, white women had higher rates than black women. The association between rates of early- and late-onset breast cancer among the two racial groups remained constant for tumors of differing grade, size, estrogen receptor status and lymph node involvement, Reuters reports. The researchers said that the pattern most likely is the result of different types of breast cancer in black women and white women.
The results did not vary after several breast cancer risk factors were considered, which indicates the differences between blacks and whites cannot be "fully explained by known risk factor variations," according to the researchers. They added that future studies are needed to "assess the interaction between age and race" because it seems that "early- and late-onset types of breast cancer are distinctly different diseases" (Reuters, 12/9).
An abstract of the study is available online.