Abstract

Neighborhood and Racial Disparities in Triple Negative Breast Cancer

Kirsten Eom, PhD, MPH¹, Kristen Berg, PhD², Natalie Joseph, MD³, Kristen Runner, RN³, Yasir Tarabichi, MD⁴, Amer Khiyami, MD⁴, Adam Perzynski, PhD², Khalid Sossey-Alaoui, PhD⁵ (1)Case Western Reserve University, (2)MetroHealth Population Health Research Institute, (3)MetroHealth Cancer Center, (4)MetroHealth Medical Center, (5)Case Western Reserve University School of Medicine

APHA 2022 Annual Meeting and Expo

Substantial racial disparities in breast cancer outcomes have been previously described, with the most severe among individuals with triple negative breast cancer (TNBC). Other studies have shown that TNBC has a high propensity to recur rapidly, be diagnosed at younger ages, and shows inferior response to standard-of-care chemotherapies and poorer prognosis than other subtypes of breast cancer. Nationally, TNBC incidence is more than double in non-Hispanic Black, compared to non-Hispanic white women. Studies of multiple health conditions and care processes have found that neighborhood socioeconomic position is a key driver of health disparities. We examined (1) the extent to which neighborhood socioeconomic position (measured by the area deprivation index or ADI) is associated with TNBC and (2) the distribution of ADI across racial/ethnic groups among women with TNBC and other subtypes of breast cancer.
We combined tumor registry data on all breast cancer cases at the MetroHealth System from 2007-2020 (N=2,282) with electronic health record data and geocoded area-based measures from the American Community Survey. Using the R sociome package, we extracted the ADI for the year nearest to patient diagnosis year. We performed cross-tabulation and group comparisons.
Of the 2,284 breast cancer cases, 193 (8.5%) were TNBC. TNBC was most common (p<0.001) among Non-Hispanic Black patients (n=103, 53.7%) vs Non-Hispanic White (n=89, 46.4%), and Hispanic patients (n=16, 8.3%). TNBC patients had a lower median age at diagnosis of 58.5 vs. 60.5 for other breast cancer patients (p<0.05). TNBC cases were more than twice as likely to have died of breast cancer (11.9% vs. 4.2% p<0.001). Higher ADI was associated with having TNBC (Mean ADI=110.2) vs. other forms of breast cancer (Mean ADI=105.4, p<0.01, comparative distribution is presented in Figure 1). A far higher proportion of non-Hispanic Black women with TNBC (43.7%) vs Non-Hispanic White women with TNBC (12.8%) resided in the most disadvantaged (highest quartile of ADI) neighborhoods (p<0.001). To our knowledge, this is the first study to examine prevalence of TNBC vs. other breast cancer subtypes across distributions of neighborhood socioeconomic position. Our findings suggest that both neighborhood socioeconomic position and race are powerfully associated with having TNBC vs. other breast cancer subtypes. The burden of TNBC appears to be highest among African American women in the most socioeconomically disadvantaged neighborhoods. These findings suggest that a complex interplay of social conditions and biological disease characteristics contribute to racial disparities in breast cancer outcomes.