Abstract PO-155: Social determinants of receptor positive breast cancer patients’ survival in Louisiana
Authors: Rivera-Irizarry Alejandra M. , Danos Denise , Wang Xinnan , Fu Qiufan , Wu Xiao-Cheng , Scribner Richard , Miele Lucio , Hossain Fokhrul 
Published: December 2020

Breast carcinoma is the most commonly diagnosed cancer in Louisiana women. Four molecular subtypes of breast cancer are classified by the presence or lack of certain hormone receptors (HR), specifically estrogen and progesterone receptors, and the Human epidermal growth factor 2 (HER2) including: Luminal A (HR+/HER2-), Luminal B (HR+/HER2+), HER2-enriched (HR-/HER2+), and Triple-Negative Breast Cancer, TNBC (HR-/HER2-). Although it is now known that genetics has a role in the risk of breast cancer incidence, other factors such as age, race, and neighborhood also have an effect on prognosis and survival. Previously we have reported that in Louisiana neighborhood concentrated disadvantage index (CDI) explained the racial disparities in TNBC stage at diagnosis and survival, but not the disparities present in incidence. The purpose of this study is to assess the association of social determinants in Luminal A, Luminal B, and HER2-enriched breast cancers patients’ survival. This population-based study used 2010-2016 breast cancer data from the Louisiana Tumor Registry (LTR) and the data of the population at risk was obtained from the US Census. To assess neighborhood environment, CDI scores were calculated based on the PhenX Toolkit Protocol. We performed regression analysis of survival data based on the cox proportional hazard models using PHREG. A total of 21,005 breast cancer patient’s data were initially screened for the study with Luminal A (14,437), Luminal B (2,345), HER2-enriched (1,089) and TNBC (3134) diagnosis. Caucasian women (White) represented 68.5%, African women (Black) represented 30.42% and “other” race represented 1.09% of the breast cancer patients. Using Wald Chi-square tests, we compared stage of diagnosis (distant, regional) and CDI among Black and White patients of all three receptor positive breast cancers. For Luminal A, stage of diagnosis, [Distant: (Pr&gt;ChiSq &lt;0.0001), Hazard Ratio, HR:32.4] and Regional: (Pr&gt;ChiSq &lt;0.0001), HR:3.56], and race (Pr&gt;ChiSq &lt;0.0001, HR:1.58]) were significant, but not the CDI [(Pr&gt;ChiSq: &lt; 0.812), HR:1.0]. For Luminal B, stage of diagnosis, [Distant: (Pr&gt;ChiSq &lt;0.0001), HR:30.17] and Regional: (Pr&gt;ChiSq &lt;0.0001), HR:4.49], and race (Pr&gt;ChiSq &lt;0.0065, HR:1.62]) were significant, but not the CDI [(Pr&gt;ChiSq: &lt; 0.288), HR:0.91]. For HER2, stage of diagnosis, [Distant: (Pr&gt;ChiSq &lt;0.0001), HR:14.798] and Regional: (Pr&gt;ChiSq &lt;0.0001), HR:2.765], was significant, but race (Pr&gt;ChiSq &lt;0.254, HR:1.26]) and CDI [(Pr&gt;ChiSq: &lt; 0.75), HR:1.0] were not. We found significant racial difference in survival in Luminal A and Luminal B breast cancer subtypes but not in HER2-enriched subtype. However, we didn’t find any significant contribution of CDI in receptor positive breast cancer patient survival.

Future studies should focus on assessing the processes by which social determinants affect receptor positive breast cancer disease progression.

Citation Format: Alejandra M. Rivera-Irizarry, Denise Danos, Xinnan Wang, Qiufan Fu, Xiao-Cheng Wu, Richard Scribner, Lucio Miele, Fokhrul Hossain. Social determinants of receptor positive breast cancer patients’ survival in Louisiana [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-155.