Abstract P4-03-06: Clinical and socioeconomic disparities in treatment and survival between Hispanic and non-Hispanic Black women with non-metastatic Triple-Negative Breast Cancer
Authors: Soto Alvaro Alvarez , Bernal Ana Maria , Mesias Jesus Anampa 
Published: March 2023

Abstract
Background: Breast cancer(BC) is a common female malignancy [1]. Triple-negative breast cancer (TNBC) is the least common (10-15% of cases)[2], but the most aggressive subtype. TNBC accounts for 5% of all-cancer-related deaths every year[3, 4].Hispanic women are 1.3 more likely to develop TNBC [3, 5]. Whether Hispanic and non-Hispanic patients suffering from TNBC show different survival. We aim: (1) to evaluate the differences in overall (OS) and breast cancer specific survival(BCSS) between Hispanic(H) and non-Hispanic black (NHB) women in non-metastatic TNBC, and (2) to assess the contribution of sociodemographic, clinical, and neighborhood factors to TNBC survival disparities. Methods: With the SEER database of the National Cancer Institute, we identified 4271 (39%) H and 6594 (61%) NHB patients who were diagnosed with non-metastatic TNBC between 2010 and 2016. Patients with tumor in situ were excluded from the analysis. Logistic regression was used to identify odd ratios for treatment modalities. Kaplan-Meir methods were used to estimate OS and BCSS. Competing risk analysis was used to asses the association between race/ethnicity and risk of breast cancer mortality adjusting for age, insurance, social, SDI, rurality, BC stage, tumor grade, surgery, chemotherapy, and radiation therapy. Results: The mean age at diagnosis for H vs. NHB was 53 and 56 years, respectively (p &lt; 0.001). 54% of Hispanics were married vs. 35 % of NHB, p &lt; 0.001. Tumor size &gt; 5 cm was present in 14% NHB vs. 12% H patients, p &lt; 0.001. Grade I tumors were only 1 % in both groups, grade II were 13% and grade III-IV were 82% also in both groups, p &gt;0.99. H (28% stage I, 50% stage II) had more advance disease as compared to NHB (30% stage I, 48% stage II) [p &lt; 0.001]. Private insurance was more common in NHB than H (74% vs. 66%, p &lt; 0.001). Rural residence was more common in NHB than H (8% vs. 3 %, p&lt; 0.001). High level of SDI was more common in H as compared to NHB(43% vs. 36%, p &lt; 0.001). Surgery was performed in 92% of NHB and 91% of H, p = 0.03. Radiation was given to 54% of NHB and 43% of H, p &lt; 0.001, while chemotherapy was given to 79% of NHB and 79% of H patients, p = 0.54. After adjusting for clinicopathological features, the odds ratio (ORs) for receiving surgery, radiation, and chemotherapy for NHB as compared to H were 0.9 (p = 0.32), 1.57 (p &lt; 0.001), and 0.89 (p = 0.03), respectively. The 5-year OS and BCSS rates were higher in H as compared to NHB(OS 76% vs. 72%, p &lt; 0.001; BCSS 81% vs. 78%, p &lt; 0.001). For stage I patients, neither 5-year OS (86% vs. 89%, p= 0.054) nor BCSS (91% vs. 93%, p= 0.37) was different between NHB and H patients. For stage II and III patients, the 5-year OS rates for Hispanics vs. NHB were (79% vs 74%, p &lt; 0.001) and (51% vs 45%, p &lt; 0.004), respectively. After adjusting for age, marital status, insurance, stage, grade, treatment, SDI, rurality; NHB have higher risk of BC death as compared to H patients (subdistribution Hazard Ratio (HR) = 1.39; 95% CI 1.2 – 1.56, p &lt; 0.001). The association between race/ethnicity and risk of breast cancer death was not affected by age (p=0.44), insurance(p=0.89), SDI(p=0.40), or living in a rural area(p=0.14). The risk of BC death between NHB and H was even higher for patients who did not receive radiation (HR 1.5) than in those who received radiation (HR 1.2). The risk of BC death between NHB and H was also higher for patients who did not undergo surgery (HR 1.7) than in those who underwent surgery (HR 1.3). Conclusions: In patients with non-metastatic TNBC, H patients present with increased rates of high-grade and advanced stage tumors than NHB. NHB are 57% more likely to receive radiation and 11% less likely to receive chemotherapy than H women. NHB patients have a 39% higher risk of BC death as compared to H even after adjusting for clinicopathological, treatment and socioeconomic factors. Future studies need to assess potential etiologies for racial disparities in BC outcomes such as differences in tumor microenvironment, access to healthcare, tumor biology and treatment efficacy.
Citation Format: Alvaro Alvarez Soto, Ana Maria Bernal, Jesus Anampa Mesias. Clinical and socioeconomic disparities in treatment and survival between Hispanic and non-Hispanic Black women with non-metastatic Triple-Negative Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-03-06.