Breast Cancer Incidence Climbs as Death Rate Decrease Slows

October 4, 2019
Seth Augenstein
Seth Augenstein

Remarkable gains have been made in breast cancer outcomes; however, racial disparities have contributed to breast cancer incidence.

Breast cancer detection and treatment have completely changed outcomes for millions of American women over the last 30 years. As of this year, there were 3.8 million women with a history of breast cancer living in the United States – and recent estimates state that 375,900 deaths have been averted, with a death rate that has plunged by 40% since 1989.

However, these remarkable gains have begun to slow down, while breast cancer incidence has increased slightly, according to a new report by the American Cancer Society (ACS).

Part of this is attributed to racial disparity, according to the researchers. “Reasons for the slowing of the decline in breast cancer mortality in recent years are not known, but may reflect widespread diffusion of the major treatment advances of the past several decades, particularly among white women, as well as the increase in incidence,” they wrote.

The study is the ACS’s biennial update on female breast cancer in America. The latest data incorporates the 5-year period from 2012 to 2016.

The death rate from breast cancer historically declined in the US by about 1.9% from 1998 through 2011. But that decline slowed to 1.3% from 2011 to 2017, according to the latest findings from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program and the CDC’s National Program of Cancer Registries.

Breast cancer incidence increased 0.3% over that same time frame-largely due to rising rates of local stage and hormone receptor (HR)-positive disease.

“The increase in the rates of HR(-positive) breast cancer is likely driven in part by increasing prevalence of excess body weight and declining fertility rates-risk factors that are more strongly associated with this subtype,” the ACS said in a statement regarding the results.

The rate of ductal carcinoma in situ (DCIS) increased more than 11-fold from 1980 to 2008-but then decreased 2.1% from 2012 to 2016, which largely reflects rising trends in the use of mammography, which increased from 29% in 1987 to 70% in 2000. Of note, this rate was reported to be slightly lower as of recent.

The disease remains more deadly for black women, which may also explain some of these trends, the researchers wrote. Despite breast cancer incidence being slightly lower for black women, the death rate remains 40% higher for this patient population in comparison with white women (28.4 vs 20.3 deaths per 100,000 people, respectively).

Breast cancer was the leading cause of cancer deaths for black women from 2016 to 2017 in 6 states: Arizona, Colorado, Florida, Georgia, Mississippi, and South Carolina. In that same time frame, it was the leading cause of cancer death among the white women in Utah.

The statistics also showed that the lifetime breast cancer diagnosis risk was 12.8%-accounting for roughly 1 in 8 women in the US.

Optimal breast cancer treatment has been largely available to white women, which may explain part of the slowdown in mortality gains, Carol DeSantis, MPH, of the ACS, explained in the statement.

“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,” she added.

References:

DeSantis CE, Ma J,  Guadet MM, et al. Breast cancer statistics, 2019. CA Cancer J Clin. 2019;0:1–14. doi:10.3322/caac.21583. https://onlinelibrary.wiley.com/doi/full/10.3322/caac.21583