Abstract A099: Oncotype Dx test receipt among Latina women with breast cancer: A population-based retrospective cohort study

Abstract

Abstract Introduction. The clinical utility of Oncotype Dx (ODx) testing, in order to estimate breast cancer (BrCa) recurrence risk and chemotherapy benefit, is widely accepted. However, population-based data on the utilization of ODx testing among Latina BrCa patients are limited. In this study, we are examining eligibility and receipt of ODx testing among Latinas in New Jersey diagnosed with breast cancer from 2008 to 2013, and assessing factors associated with ODx test receipt in the population. Methods. Data on all primary, histologically confirmed, invasive BrCa cases diagnosed among women between January 1, 2008 and December 31, 2013 (N=32,770) were retrieved from the New Jersey State Cancer Registry. In order to identify Latina cases, those that were coded not as Non-Hispanic on the North American Association of Central Cancer Registries Hispanic Identification Algorithm were included in the analytic sample. Guideline-concordant ODx testing was classified as testing among Stage IA, Stage IB, Stage IIA or Stage IIB, node-negative, estrogen receptor-positive and/or progesterone receptor-positive, human epidermal growth factor receptor-negative cases. Results. Approximately 9% of the total population-based sample of invasive BrCa cases were Latinas (n= 3,036). Among them, the average age at diagnosis was 55.8±13.3 years, 76.0% had ductal carcinoma histology, and 7.8% and 11.1% were non-luminal HER2-expressing and triple-negative subtypes, respectively. In terms of eligibility for ODx testing, 45.8% (1,391/3,306) were eligible and among them, 23.9% (333/1,391) received the test. Among those ineligible for ODx testing, 2.6% (43/1,645) received the test. Conclusions. The underutilization of guideline-concordant ODx testing among eligible Latina BrCa cases in New Jersey (<50%) could indicate that there is unequal access to appropriate genetic testing and optimal adjuvant chemotherapy. This might exacerbate disparities as BrCa is a leading cause of cancer death among Latinas. Our future aims include assessment of factors associated with guideline-concordant ODx test receipt among Latinas, and the impacts of ODx test receipt on BrCa treatment and survival. Citation Format: Nicholas Acuna, Antoinette M. Stroup, Jennifer Tsui, Adana A.M. Llanos. Oncotype Dx test receipt among Latina women with breast cancer: A population-based retrospective cohort study [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A099.