Abstract P5-12-03: Socio-demographic differences in utilization of genomic testing and receipt of endocrine therapy in the National Cancer Database
Authors: Ko Naomi Y , Muhammad Mustafa Q , Cassidy Michael R , Oshry Lauren , Hirsch Ariel E 
Published: March 2020

Background & Objectives Breast cancer outcome disparities for racial and ethnic minorities continues to be a problem in the United States. Genomic testing in early stage hormone positive breast cancer is the current standard of care given the useful predictive and prognostic value of testing. However, chemotherapy treatment decisions based on genomic testing results are predicated on the assumption that patient adhere to adjuvant endocrine treatment. Factors that could contribute to ongoing disparities for racial and ethnic minorities include both the utilization of genomic testing and adherence to hormonal therapy. Understanding these patterns of care across the United States with a large dataset has not yet been done. Methods We analyzed a cohort from the National Cancer Database (NCDB) of 387,008 female patients diagnosed with Stage I-II, ER+ breast cancer between 2010 and 2014. Demographic variables included age, race, ethnicity, insurance status, income, education, Charlson-Deyo comorbidity score. Clinicopathologic and treatment variables included tumor grade, histology, receptor status, facility type, delivery of treatment at &gt;1 facility and receipt of genomic testing. Descriptive statistics using chi-square testing were computed to describe patient, tumor and treatment characteristics. Logistic regression analysis was used to calculate odds of genomic testing and receipt of hormone therapy among patients who did or did not receive genomic testing.

Results Among a total sample size of 387,008, median age was 63 years old, majority white (87%), non-Hispanic (95.4%), without co-morbidities (88%). A total of 147,863 (38.2%) patients underwent genomic testing. Compared to patients with ages 18-&lt;50, older age (≥70 years) was associated with a lower adjusted odds of genomic testing (OR=0.33; 95% CI=0.32-0.34, p=&lt;0.0001). Blacks had a lower odds of receiving genomic testing on multivariate analysis compared to whites (OR=0.82; 95% CI=0.80-0.85, p=&lt;0.0001). Hispanic ethnicity, non-private insurance, increasing percentage of no high school degree in area of residence, CDS score of 2 or more, stage II disease, community or comprehensive community facility setting, and borderline HER2 status were also factors associated with a lower odds of receiving a genomic test. Odds of getting genomic testing improved over the years with patients diagnosed in 2014 reporting an odds ratio of 1.57 (95% CI=1.53-1.60, p=&lt;0.0001) compared to those diagnosed in 2010. Compared to whites, blacks had a lower odds of receiving hormone therapy irrespective of genomic testing status (OR=0.86; 95% CI=0.83-0.88, p=&lt;0.0001). Age ≥70 (OR=0.53; 95% CI=0.51-0.55, p=&lt;0.0001), Hispanic ethnicity (OR=0.89; 95% CI=0.85-0.93, p=&lt;0.0001), non-private insurance and non-academic treatment facilities were associated with lower odds of getting hormone therapy. Among patients undergoing a genomic test, age ≥70, black race, and non-academic treatment facilities had lower odds of receiving hormone therapy. Conclusion In a national cohort of breast cancer patients, Black women consistently were less likely to get genomic testing and less likely to receive hormonal therapy. Ensuring that all women with early stage ER+ breast cancer eligible for genomic testing and hormone therapy receive appropriate testing and hormonal treatment is a priority to addressing breast cancer disparities.

Citation Format: Naomi Y Ko, Mustafa Q Muhammad, Michael R Cassidy, Lauren Oshry, Ariel E Hirsch. Socio-demographic differences in utilization of genomic testing and receipt of endocrine therapy in the National Cancer Database [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-12-03.