Rising incidence erasing decades-old gap
Breast cancer rates among African American women in the United States have continued to increase, converging with rates among white women and closing a gap that had existed for decades. The finding is part of Breast Cancer Statistics, 2015, published in CA: A Cancer Journal for Clinicians, and its accompanying consumer publication, Breast Cancer Facts & Figures.
Excluding skin cancers, breast cancer is the most common cancer diagnosed among U.S. women, accounting for nearly one in three cancers. It is also the second leading cause of cancer death among women after lung cancer. Approximately 231,840 new cases of invasive breast cancer and 40,290 deaths are expected among U.S. women in 2015.
From 2008 to 2012, breast cancer incidence rates increased in African American women (0.4% per year), and among Asian/Pacific Islanders (1.5% per year), while they remained stable among whites, Hispanics, and American Indian/Alaska Natives. In 2012, overall breast cancer incidence rates converged between blacks and whites as a result of increasing incidence rates in black women and stable rates in white women. Notably, rates were higher in blacks than whites in seven states (Alabama, Kentucky, Louisiana, Mississippi, Missouri, Oklahoma, and Tennessee). While the reason for rising incidence in African American women is not clear, the authors note that the increase in incidence has been driven by increases in ER positive breast cancers and may reflect rising rates of obesity.
Mortality rates continued to be higher in black women than in white women, despite historically lower incidence rates among black women. The black-white disparity in breast cancer death rates has increased over time; by 2012, death rates were 42% higher in black women than white women. The authors say that trend is likely to continue--at least in the near future--in view of the increasing trends in breast cancer incidence rates in black women.
Other findings from the report:
- More than 3.1 million US women with a history of breast cancer were alive on January 1, 2014 (the most recent data available). Most of them were cancer-free, while others still had evidence of cancer and may have been undergoing treatment.
- Breast cancer mortality rates have dropped 36% since 1989, which translates to 249,000 breast cancer deaths averted.
- From 2003 through 2012, breast cancer death rates declined annually by 1.8% in whites, 1.5% in Hispanics, 1.4% in blacks, and 1.0% in Asian/Pacific Islanders, but remained unchanged among American Indians/Alaska Natives.
- During 2003-2012, death rates declined significantly for white women in every state, but for black women in only 27 of 30 states with sufficient data to examine trends. In 3 states (Mississippi, Oklahoma, and Wisconsin) death rates were stable.
- Black women have the highest breast cancer death rate of any racial/ethnic group. They are also more likely to be diagnosed at later stages and have the lowest survival at each stage of diagnosis. Reasons include lack of regular screening and/or follow up of suspicious results, lack of access to timely, high-quality treatment, and higher proportion of aggressive, harder to treat tumors.
- The distribution of breast cancer subtypes varies by race/ethnicity. Black women are more likely to be diagnosed with triple negative breast cancers, an aggressive breast cancer subtype linked to poorer survival.
- In 2013, 69% of women 45 years of age and older reported having a mammogram within the past 2 years. Screening rates are lower for women who are uninsured or have lower educational attainment and for Hispanics and American Indian/Alaska Natives.