Abstract C039: Differences in breast cancer survival by race, age, and tumor estrogen receptor status
Authors: Ewane Ewune , Yi Min , Akhtar A. , Brewster Abenaa M. , McNeil-Haughton Lorna , Hunt Kelly K. , Black Dalliah M. 
Published: August 2020

Background: Improvements in breast cancer survival can be attributed to screening programs resulting in earlier diagnosis, treatment advances, and more accessible care. However, racial disparities continue to persist. Identifying the most vulnerable populations can help strategize efforts of programs focused on improving disparities. The purpose of this study is to determine trends in breast cancer disease-specific survival (DSS) in black patients compared to white patients by age at diagnosis, year of diagnosis, and tumor estrogen receptor (ER) status.

Methods: The Surveillance, Epidemiology, and End Results database was utilized to identify patients of black or white race diagnosed with stage I-III, ER-positive (+) or ER-negative (-) breast cancer between 1990 and 2005. The Kaplan-Meier method was used to determine 10-year breast cancer DSS. Changes in DSS were analyzed over the study's time period and in 4 age groups to evaluate women who were of premenopausal age (&lt; 50 years), perimenopausal or postmenopausal and of the average age for breast cancer diagnosis (50-64 years), elderly (65-79 years), and most elderly (≥80 years).

Results: The study included 634,434 white (89.8%) and 72,124 black (10.2%) women. In all age groups and years of diagnosis, white patients with ER+ or ER- disease had significantly higher DSS compared to blacks (p&lt;0.05); in patients 50-64 years old diagnosed in 2000-2005, white patients with ER+ cancer had an 88% DSS compared to 77% DSS for black patients and, for ER- disease, whites had a 76% DSS compared to 67% for blacks. All patients diagnosed most recently had stable or improving DSS, except for black patients age ≥80 years who had a significantly lower DSS of 47% for those diagnosed in 2000-2005 compared to 52% for those diagnosed in 1990-1994 (p&gt;0.05). All black patients diagnosed in 2000-2005, independent of age and tumor receptor status, had significantly lower disease-specific survival (DSS) compared to white patients diagnosed a decade earlier in 1990-1994 (p&lt;0.05). For women &lt;50 years of age with ER+ cancer, black patients diagnosed between 2000-2005 had a DSS of 75% compared to 81% in white patients diagnosed between 1990-1994. Among black patients, only young women &lt;50 years of age with ER+ or ER- cancer had consistent and the most improvement in DSS over the study's 3 time intervals; for ER+ cancer, DSS was 68% for those diagnosed in 1990-1994, 71% for 1995-1999, and 75% for 2000-2005 and for ER- cancer, the DSS was 60% for those diagnosed in 1990-1994, 63% for 1995-1999, and 67% for 2000-2005 (p&lt;0.05).

Conclusion: Black and white women have experienced improvements in breast cancer DSS, particularly in young black patients &lt; 50 years of age with ER+ or ER- disease. However, DSS remained lower in all black patients compared to white patients, independent of year of diagnosis, age, and tumor receptor status. Future efforts are needed to identify and address the causes of continued disparities in breast cancer DSS, particularly in subsets of black patients not having survival improvements.

Citation Format: Ewune Ewane, Min Yi, A. Akhtar, Abenaa M. Brewster, Lorna McNeil-Haughton, Kelly K. Hunt, Dalliah M. Black. Differences in breast cancer survival by race, age, and tumor estrogen receptor status [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C039.