Racial disparities in individual breast cancer outcomes by hormone-receptor subtype, area-level socio-economic status and healthcare resources

Abstract

The aim of the study is to determine the influence of area-level socio-economic status and healthcare access in addition to tumor hormone-receptor subtype on individual breast cancer stage, treatment, and mortality among Non-Hispanic (NH)-Black, NH-White, and Hispanic US adults. Analysis was based on 456,217 breast cancer patients in the SEER database from 2000 to 2010. Multilevel and multivariable-adjusted logistic and Cox proportional hazards regression analysis was conducted to account for clustering by SEER registry of diagnosis. NH-Black women had greater area-level access to healthcare resources compared with women of other races. For instance, the average numbers of oncology hospitals per million population in counties with NH-Black, NH-White, and Hispanic women were 8.1, 7.7, and 5.0 respectively; average numbers of medical doctors per million in counties with NH-Black, NH-White, and Hispanic women were 100.7, 854.0, and 866.3 respectively; and average number of Ob/Gyn in counties with NH-Black, NH-White, and Hispanic women was 155.6, 127.4, and 127.3, respectively (all p values <0.001). Regardless, NH-Black women (HR 1.39, 95 % CI 1.36–1.43) and Hispanic women (HR 1.05, 95 % CI 1.03–1.08) had significantly higher breast cancer mortality compared with NH-White women even after adjusting for hormone-receptor subtype, area-level socioeconomic status, and area-level healthcare access. In addition, lower county-level socio-economic status and healthcare access measures were significantly and independently associated with stage at presentation, surgery, and radiation treatment as well as mortality after adjusting for age, race/ethnicity, and HR subtype. Although breast cancer HR subtype is a strong, important, and consistent predictor of breast cancer outcomes, we still observed significant and independent influences of area-level SES and HCA on breast cancer outcomes that deserve further study and may be critical to eliminating breast cancer outcome disparities.

Tumour-infiltrating lymphocytes in advanced HER2-positive breast cancer treated with pertuzumab or placebo in addition to trastuzumab and docetaxel: a retrospective analysis of the CLEOPATRA study

“…Other studies have shown worse survival in black or African American women with breast cancer than in women of other ethnicities. 21 Host factors governing tumour immune responses remain largely unexplored. The concept of ethnic differences in antitumour immunity warrants further investigation, and could partly account for differences in cancer outcomes.…”

Pollution and regional variations of lung cancer mortality in the United States

“…In addition, we identified that counties with higher lung cancer mortality rates are in areas with greater community-level disadvantages such as greater poverty, poorer education, higher unemployment, and higher rates of uninsured adults. Research has consistently shown that greater access to healthcare and higher socioeconomic status is associated with lower risk of cancer mortality [31–34]. Tannenbaum et al (2014) found that individuals living in communities with the highest SES had a 13% reduced hazard (HR: 0.87, 95%CI: 0.84–0.91) for lung cancer mortality compared to individuals living in impoverished communities.…”

Mapping hot spots of breast cancer mortality in the United States: place matters for Blacks and Hispanics

“…Several factors likely contribute to racial differences in breast cancer mortality and in particular, the observed geographic clustering. However, studies suggest that the most significant causes relate to lack of adequate and timely screening necessary for early detection, and lack of access to adjuvant chemotherapy and/or surgical interventions [2, 6, 44-55]. Fedewa et al (2011) reported that NH-Blacks were 25% to 106% more likely to have delayed breast cancer chemotherapy after 30-, 60-, and 90-days following breast cancer diagnosis [48].…”

“…NH-Black and Hispanic women have up to a 50% increased risk for late-stage breast cancer diagnoses [4, 5], and experience higher breast cancer mortality when compared with NH-Whites [6-11]. An increased risk of late stage breast cancer diagnosis is associated with residing in highly segregated areas and decreased access to mammography.…”

“…Prior research also suggests that Black and Hispanic women living in poor and/or racially segregated communities are more likely to be diagnosed with late-stage breast cancer and when compared with their NH-White counterparts [4-10, 12-18]. In addition, a recent analysis of data from Surveillance, Epidemiology, and End Results (SEER), showed that when compared with NH-White women, and after controlling for breast cancer hormone-receptor subtype, area-level socioeconomic status, and healthcare access, NH-Blacks and Hispanics had a 39% and 5% increased risk of breast cancer mortality, respectively [6]. These studies suggest that social and built environmental risk factors such as availability of quality cancer screening and treatment resources may lead to clustering of breast cancer mortality in specific regions, and partly explain racial disparities in mortality rates among US women.…”