African-American women under the age of 40 have a higher risk of breast cancer than do white women of a similar age. White women aged 40 and older, however, have a higher incidence than black women aged 40 and older.
The incidence of postmenopausal breast cancer is associated with screening and hormone therapy. The mechanisms that influence the incidence of breast cancer in premenopausal women are less well understood.
To get a better understanding of disease trends in younger women, Louise Brinton, Ph.D., of the National Cancer Institute in Bethesda, Md., and colleagues analyzed the incidence of breast cancer among 387,231 women diagnosed between 1992 and 2004 who were included in the Surveillance, Epidemiology, and End Results (SEER) database.
The investigators found that the incidence rate of breast cancer was 16.8 per 100,000 for black women under the age of 40, compared with 15.1 per 100,000 for white women under the age of 40. The black-white incidence rate ratio was highest for women under the age of 30, with black women having a 52 percent higher incidence than white women. During the study years, only white women over the age of 40 had a statistically significant increase in the incidence of invasive breast cancer
"Continued surveillance of trends is needed, particularly for molecular subtypes that preferentially occur among young women," the authors conclude.
This research was published in the Journal of the National Cancer Institute November 11, 2008.
Materials provided by Journal of the National Cancer Institute. Note: Content may be edited for style and length.
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