Report: Breast Cancer Incidence Rates Converging Among White and African-American Women
Rates increasing among African-Americans, reasons unclear (October 1)
Breast cancer incidence rates increased slightly among African-American women from 2006 to 2010, bringing those rates closer to the historically higher rates among white women, according to a new analysis by American Cancer Society (ACS) researchers. The explanation behind the rise is unclear.
The new findings were published in CA: A Cancer Journal for Clinicians.
From 2006 to 2010, incidence rates increased for estrogen receptor-positive (ER+) breast cancers in the youngest white women, in Hispanic women in their 60s, and in all but the oldest African-American women. In contrast, estrogen receptor-negative (ER–) breast cancers declined among most age and racial/ethnic groups.
In every age group, white women had the highest rates of ER+ breast cancer, and African-American women had the highest rates of ER– breast cancer. These differences may reflect racial variations in the prevalence of risk factors that differ by ER status. For example, reproductive history and obesity appear to be more strongly associated with ER+ breast cancer, whereas lower socioeconomic status is associated with an increased risk of ER– breast cancer.
Historically, white women have had the highest breast cancer incidence rates among women aged 40 years and older. However, incidence rates are now converging among white and African-American women, particularly among women aged 50 to 59 years.
The new report notes that breast cancer death rates have dropped by 34% since 1990 in all racial/ethnic groups except American Indians/Alaska Natives. Nevertheless, survival disparities persist by race/ethnicity, with African-American women having the poorest breast cancer survival of any racial/ethnic group.
In 2010, 67% of U.S. women 40 years old and older reported having a mammogram within the past 2 years. The mammography screening rate peaked in 2000, declined slightly, and has been stable since 2005. The report also finds that in general, states with higher rates of mammography screening had fewer late-stage breast cancers diagnosed among non-Hispanic white women. Despite similar overall screening rates, African-American women have remained more likely to be diagnosed with regional and distant-stage breast cancers compared with white women, which the authors say may reflect differences in the quality of mammography screening and delayed follow-up for abnormal mammography findings.
Source: ACS; October 1, 2013.