Breast Cancer: Why do Black women have a 40% higher risk of dying? Experts weigh in
Breast cancer is the most commonly diagnosed cancer among Black women, with 33,840 new cases estimated to have been diagnosed in 2019 alone. Despite similar rates of breast cancer occurrence among White and Black women, African-Americans have a 39-40% higher risk of dying from breast cancer, compared with their White counterparts, according to multiple studies.
The breast cancer incidence rate has been lower among Black women than it has among White women for several decades. However, the incidence rate among Black women has been rising steadily during that time while it has fluctuated among White women, reveals the cancer disparities progress report 2020 by the American Association for Cancer Research (AACR). As a result of the disproportionate increase in the breast cancer incidence rate among Black women, incidence rates for this type of cancer are now very similar for African-Americans and White women. The incidence of triple-negative breast cancer, a particularly aggressive form of breast cancer, is also twice as high among Black women compared to White women.
“In contrast to the incidence rate, the breast cancer death rate is 39% higher for African American women compared with White women. Many factors contribute to the breast cancer death rate disparity, including African-American women being more likely to be diagnosed at a later stage of the disease, when treatment is less likely to be successful, and being more likely to be diagnosed with triple-negative breast cancer, which is a biologically aggressive form of breast cancer with a poor prognosis,” explains AACR.
The American Cancer Society (ACS) says breast cancer is the second most common cause of cancer death among Black women surpassed only by lung cancer. Over 6,500 deaths from breast cancer were estimated to have occurred among Black women in 2019. “Breast cancer death rates in 2012-2016 are about 40% higher in Black women compared to White women. The overall 5-year relative survival rate for breast cancers diagnosed in 2008-2014 was 81% for Black women compared to 91% for White women,” it says. Another ACS report suggests that over a 10-year period, between 2007-2016, the pace of decline in breast cancer death rates has been somewhat slower among non-Hispanic (NH) Black women, than among NH White women. “As a result, breast cancer death rates remain 41% higher in NH Black women than in White women,” it adds.
According to a 2016 study by the US Centers for Disease Control and Prevention (CDC), breast cancer death rates are 40% higher among Black women than White women. Breast cancer was also more likely to be found at an earlier stage among White women than among Black women. Among women who were 60 to 69 years old, breast cancer death rates dropped 2% per year among White women, compared with 1% per year among Black women. This was the largest difference by race.
Black women are also more likely to be diagnosed with breast cancer at a younger age than White women. “Breast cancer incidence rates are higher among Blacks than Whites for women under 45. The median age of diagnosis is 59 for Black women, compared to 63 for White women,” says the ACS.
What factors contribute to the disparity?
Delay in treatment: After a breast cancer diagnosis, Black women experience longer waits for starting treatment than White women, and their duration of treatment is prolonged, suggests a new study. It included 2,841 participants (roughly equal numbers of Black and White women) with stage I-III breast cancer in the Carolina Breast Cancer Study, a population-based study. The overall median time to treatment initiation was 34 days. More Black women experienced a delayed time to treatment (13.4% versus 7.9%) and a prolonged duration of treatment (29.9% versus 21.1%) compared with White women. Among women with high socioeconomic status, 11.7% of Black women experienced delays in initiating treatment compared with 6.7% of White women. “Even among women with low socioeconomic status, we still saw fewer delays among White women, underscoring the disparate experience of Black women, who appear to experience unique barriers,” wrote lead author Marc Emerson in the analysis published in Cancer.
Financial hardship: This extends beyond out-of-pocket direct medical costs and can be caused by indirect costs of lost productivity, such as days lost from work or disability days. Black women living in urban areas are almost 50% more likely to lose a job or income after their breast cancer diagnosis compared with White women living in urban areas. Besides, among women with breast cancer who were employed at the time of diagnosis, African-Americans are significantly less likely to be employed when asked about this at 2 and 9 months after diagnosis compared with White women.
Racial and ethnic minorities are also more likely to be uninsured or receive Medicaid compared with Whites. One recent study showed that Black, American Indian/Alaska Native, and Hispanic women were more than 30% more likely to be diagnosed with advanced-stage breast cancer compared with White women and that nearly half of this disparity was a result of these women being uninsured or receiving Medicaid. Addressing health insurance status will not completely mitigate cancer health disparities, but providing equal insurance coverage has the potential to substantially reduce the burden of cancer for racial and ethnic minorities, suggest experts.
Radiotherapy: It is an important part of curing breast cancer, in addition to surgery and chemotherapy. Research shows that racial and ethnic minority women with breast cancer are less likely to receive radiotherapy, which may contribute to a higher risk of dying from breast cancer. Compared with White women, Black women with early-stage breast cancer are half as likely to be treated with radiotherapy. Black women with breast cancer are also more likely to experience delays in beginning radiotherapy compared with White women.
Breast cancer screening: Even though the breast cancer screening rate — as defined by the percentage of women ages 50 to 74 who report having had a screening mammogram in the past 2 years — for Black women is very similar to that for white women, 9% of Black women are diagnosed with breast cancer when the disease is at an advanced stage compared with 5% of White women. The disparity in the advanced stage of diagnosis is one factor contributing to the striking disparity in the breast cancer death rates for Black and White women, which are 27.3 per 100,000 and 19.6 per 100,000, respectively.
The contributing social, clinical, and environmental factors include Black women overestimating screening mammogram utilization, having longer intervals between screening mammograms, experiencing less timely follow-up of abnormal results, being screened at lower resourced, and nonaccredited facilities, and having reduced likelihood of receiving follow-up care at a comprehensive care center.
Different stressors: Psychosocial stressors have been shown to contribute to the increased risk of certain aggressive types of breast cancer among Black women. Stress-related social and behavioral factors have been also considered as possible cancer risk factors. Racial discrimination, even perceived discrimination, which can contribute to poor physical and mental health among minorities, has been linked to breast cancer among Black women.
Environmental factors: Women in disadvantaged urban neighborhoods are significantly more likely to be diagnosed with late-stage breast cancer. One study, for example, found that Black women were significantly more likely to live in disadvantaged neighborhoods than White women and that this was an important factor contributing to disparities in triple-negative breast cancer stage at diagnosis and survival between Black and White women.
Genetic factors: According to ACS, a recent analysis comparing molecular features of breast cancers in Black and White women estimated that 40% of the racial variation in breast cancer subtype are due to inherited genetic mutations.
Physical inactivity: An estimated 4% of breast cancers in the US can be attributed to a lack of physical activity. Racial and ethnic disparities have been reported in the proportion of physically inactive individuals, with Blacks having a higher prevalence of physical inactivity compared with Whites, and these differences are not explained by socioeconomic status. Similar trends have been observed across the US for various types of physical activity, with Whites having a greater proportion of individuals who are physically active compared with Blacks and Hispanics.