Association of hot spots with de novo metastatic breast cancer survival among African-American women

Authors: Han Y, Langston ME, Fuzzel L, Lewis-Thames MW, Khan S, Moore JX

Category: Survivorship & Health Outcomes/Comparative Effectiveness Research
Conference Year: 2020

Abstract Body:
Purpose: Given geographic and racial/ethnic disparities in breast cancer survival rates, we aimed to investigate the association of geographic breast cancer mortality hot spots (counties with high breast cancer mortality rates) with de novo metastatic (or metastatic at initial diagnosis) breast cancer mortality among black women. Methods: We identified 7,292 black women diagnosed with de novo metastatic breast cancer in the Surveillance, Epidemiology and End Results (SEER)18 registries between 1990 and 2016. The county-level proportions for race/ethnicity, population with a college education, household income, obesity, smoking, etc., were obtained from 2014 County Health Rankings. We linked county-level characteristics to the SEER data using residence at the time of diagnosis. We used Cox proportional hazards models to compare breast cancer-specific mortality and all- cause mortality among black women residing in breast cancer mortality hot spots vs non-hot spot counties. Results: Among 7,292 black women, 393 (5.39%) women resided in breast cancer mortality hot spots. Women residing in hot spot counties had a similar risk of breast cancer-specific mortality (adjusted hazard ratio [aHR], 0.99; 95% confidence interval [CI], 0.86 - 1.13) and all-cause mortality (aHR, 0.98; 95% CI, 0.86 - 1.11) as women in non-hot spot counties after adjusting for age, year of diagnosis, marital status, tumor characters (histology, grade, hormone receptor status), treatments (surgery, radiation, and chemotherapy), and SEER registries. Additional adjustment for county-level characteristics did not impact the results of breast cancer-specific mortality (aHR, 0.97; 95% CI, 0.85 - 1.11) and all-cause mortality (aHR, 0.96; 95% CI, 0.84 - 1.09). Conclusions: Our findings indicate that living in a breast cancer mortality hot spot does not impact mortality among black women with de novo breast cancer at diagnosis. Any survival advantage gained from living in a breast cancer mortality non-hot spot is diminished when you are diagnosed with de novo metastatic breast cancer could be due to the issues of hot spots (access to care, screening, etc.) are also important predictors of being diagnosed with de novo metastatic breast cancer.

Keywords: de novo, metastatic breast cancer, black women, survival, breast cancer mortality hot spot