What are the racial predilections of breast cancer?

Updated: Dec 26, 2019
  • Author: Graham A Colditz, MD, DrPH; Chief Editor: Chandandeep Nagi, MD  more...
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A detailed analysis of SEER data from 1975-2004 included 440,653 cases of breast cancer and showed a consistent finding of higher age-specific incidence of breast cancer among black women compared to white women younger than 40 years. [7] After age 40 years, white women had higher incidence rates. This black-to-white incidence rate crossover was observed for all tumor characteristics and was consistent across birth cohorts. Black women have poorer 5-year survival rates from breast cancer at all ages of diagnosis compared to white women. This poorer survival can be attributed, in part, to the tendency of black women to be diagnosed at later stages of the disease. [7]  

According to a study from the American Cancer Society (ACS), in 2012, the breast cancer rates converged among black and white women even though white women have historically had higher incidence rates. Incidence rates were also significantly higher in black women compared with white women in seven states, primarily located in the South. [8, 9]  However, more recent ACS data show a convergence of breast cancer rates among black and white women aged young than 65 years, a higher incidence in white women between ages 65 and 84 years, and then another convergence at age 85 years and older (2012-2016); however, 2013-2017 data show higher death rates in black women regardless of age and across all racial and ethnic groups. [3]

Historically, breast cancer incidence rates among Asian, Hispanic, and American Indian women in the United States are considerably lower than those of non-Hispanic white women and non-Hispanic black women, and the trend continues with the most recent 5-year data sets (2012-2016). [3] The magnitude of the difference in incidence rates among various ethnic groups often depends on migrant status. For example, breast cancer incidence among Chinese-American and Japanese-American women from 1973-1986 was about 50% lower for those born in Asia and about 25% lower for those born in the United States compared to white women born in the United States. Compared with Chinese women living in mainland China, Singapore, and Hong Kong, Asian-born Chinese women living in the United States had almost twice the annual rate of breast cancer, and United States–born Chinese women had an even higher rate. [10] The pattern for Japanese women was similar.

A large body of literature shows increases in breast cancer incidence following migration from a low-risk country to the United States. Ziegler et al noted a 6-fold gradient in risk of breast cancer among Asian women depending on time since migration. [11] Findings from migrant studies strongly suggest that factors associated with the lifestyle or environment of the destination country influence breast cancer risk and are consistent with a positive relationship between duration in the destination country and adoption of that country's lifestyle. For example, among immigrants, the fertility rate and average number of children born tends to converge to the rates of the destination country.


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