Breast cancer deaths drop 39% in 25 years, but racial disparities still exist

Death rates for breast cancer fell 39% between 1989 and 2015 in the United States, saving 322,600 women from dying from breast cancer in this past quarter century, according to statistics published in CA: A Cancer Journal for Clinicians by American Cancer Society researchers.

The researchers attributed declines in breast cancer mortality rates both to early detection by mammography and to improvements in treatment, such as adjuvant chemotherapy and hormonal therapy in the 1980s and targeted therapies in the 1990s.

But not all women gained the same from these improvements. While death rates have decreased in all racial/ethnic groups since 2006, black women continue to have higher breast cancer death rates than white women—39% higher in 2015. This gap emerged in the early 1980s and continued to widen over the years. Fortunately, it has stopped growing since 2011, although it hasn’t narrowed nationwide.

The excess death rate for black women differs by state, ranging from 20% in Nevada to as high as 66% in Louisiana. In seven states, though, breast cancer death rates were statistically similar for white and black women, “perhaps reflecting an elimination of disparities and/or a lack of statistical power,” the researchers wrote.

“A large body of research suggests that the black-white breast cancer disparity results from a complex interaction of biologic and nonbiologic factors, including differences in stage at diagnosis, tumor characteristics, obesity, other health issues, as well as tumor characteristics, particularly a higher rate of triple negative cancer,” said lead author Carol DeSantis, MPH, director of American Cancer Society’s Breast and Gynecological Cancer Surveillance, Atlanta, GA.

“But,” she added, “the substantial geographic variation in breast cancer death rates confirms the role of social and structural factors, and the closing disparity in several states [Massachusetts, Delaware, and Connecticut] indicates that increasing access to health care to low-income populations can further progress the elimination of breast cancer disparities.”

Other notable statistics from the article:

• A woman living in the United States has a 12.4%—or a 1 in 8—lifetime risk of being diagnosed with breast cancer.
• Approximately 252,710 new cases of invasive breast cancer, 63,410 cases of in situ breast carcinoma, and 40,610 breast cancer deaths are expected to occur among US women in 2017.
• Women age 50 and older account for four of five (81%) breast cancer diagnoses, and nine of 10 (89%) breast cancer deaths occur in this age group.
• Although breast cancer death rates have decreased in both younger and older women, the decrease has slowed among women under age 50 since 2007.
• The percentage of women age 40 and older who reported having a mammogram (within the prior two years) jumped from 29% in 1987 to 70% in 2000—but then dropped to 64% in 2015.
• Incidence rates of hormone receptor-positive breast cancer increased among all racial/ethnic groups from 2005 to 2014, while incidence rates of hormone receptor-negative breast cancer decreased.
• The median age for all women at breast cancer diagnosis is 62 years. The median age at diagnosis is younger for black women (59 years) than for white women (63 years).
• The median age for all women at breast cancer death is 68 years; 70 years for white women and 62 years for black women.
• Compared with white women, black women have higher rates of breast cancer incidence before age 40 but lower rates between ages 65 to 84. Black women are more likely to die from breast cancer at every age.

On the upside: More than 3.5 million American women with a history of breast cancer were alive as of January 1, 2016, the researchers reported.

• Related Links:
• Breast cancer statistics, 2017, racial disparity in mortality by state