Black women continue to be at higher risk of breast cancer death compared with their white counterparts, even though the overall mortality rate for the disease has continued to decline, according to a report from the American Cancer Society (ACS) published online October 2 in CA: A Cancer Journal for Clinicians.
The report, "Breast Cancer Statistics, 2019," found that the overall breast cancer death rate has continued to decrease since 1989, for a total drop of 40% through 2017. As a result, 375,900 breast cancer deaths have been avoided in U.S. women through 2017, wrote a team led by Carol DeSantis of the ACS's Surveillance and Health Services Research Program in Atlanta. The pace of the mortality rate decline has slowed, however, from 1.9% per year between 1998 and 2011 to 1.3% per year between 2011 and 2017, the group noted.
But not all women have profited from the reduced mortality rate trend, according to DeSantis and colleagues.
"Declines in breast cancer mortality have been attributed both to improvements in treatment and to early detection by mammography," the team wrote. "However, not all women have benefitted equally from these advances, as indicated in the striking divergence in mortality trends between black and white women that emerged in the early 1980s."
In fact, between 2013 and 2017, the breast cancer death rate was 40% higher in black women compared with white women -- a disparity magnified among black women younger than age 50, who sustain a death rate from the disease that is double that of whites. Between 2016 and 2017, breast cancer exceeded lung cancer as the leading cause of cancer deaths among black women in six states (Arizona, Colorado, Florida, Georgia, Mississippi, and South Carolina).
The reason for these higher breast cancer death rates among black women could be due to various factors, including "later stage at diagnosis, unfavorable tumor characteristics, higher prevalence of obesity and preexisting medical conditions, and less access to timely and high-quality prevention, early detection, and treatment services," the group noted.
The researchers also found the following:
- Between 2013 and 2017, the breast cancer mortality rate declined by 2.1% per year in Hispanics/Latinas, 1.5% per year in blacks, 1% per year in whites, and 0.8% per year in Asians/Pacific Islanders. It was stable in American Indians and Alaska Natives.
- The breast cancer incidence rate has continued to increase by 0.3% per year since 2004, mostly due to higher rates of local stage and hormone receptor-positive disease.
- The lifetime risk of a breast cancer diagnosis is now 13%, which still translates to about 1 in 8 women diagnosed with breast cancer in her lifetime.
- Among women age 50 and older, rates of ductal carcinoma in situ (DCIS) increased from 7 cases per 100,000 in 1980 to 83 per 100,000 in 2008.
The fact that breast cancer mortality is decreasing is good news, but much more work needs to be done to close the gap between white women and black women, DeSantis noted in a statement released by the ACS.
"We can't say for sure what the reasons are for the slowing of the decline in breast cancer mortality," she said. "It could be due in part to the slight increase in incidence since 2004, as well as a sign that optimal breast cancer treatment has become more widespread, particularly among white women. However, more can and should be done to ensure that all women have access to quality care to help eliminate disparities and further reduce breast cancer mortality."
