In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 40, No. 16_suppl ( 2022-06-01), p. 1074-1074
Abstract:
1074 Background: Black women (BW) are disproportionately diagnosed with metastatic triple negative breast cancer (mTNBC) compared to Non-Hispanic White women (NHW). Median overall survival (OS) in mTNBC remains poor at 12-18 months. While immune checkpoint inhibitors (ICIs) are a promising treatment strategy, BW were significantly underrepresented in pivotal clinical trials that led to the approval of ICIs in mTNBC. Therefore, the efficacy, safety, and optimal biomarkers of ICI response in BW remain unknown. We sought to compare baseline characteristics and outcomes between BW and NHW with mTNBC treated with an ICI and chemotherapy at an urban tertiary care institution. Methods: BW and NHW with advanced unresectable or mTNBC treated with an ICI plus chemotherapy at Emory University between 2019 and 2021 were retrospectively evaluated. Baseline characteristics, including next generation sequencing (NGS), as well as clinical outcomes between BW and NHW were compared using Kruskal-Wallis tests and Fisher’s exact tests. Progression free survival (PFS) and OS were analyzed with the Kaplan-Meir method. Results: Forty-one women with PDL-1 positive mTNBC treated with an ICI and chemotherapy were identified [BW, n = 26 (63%) and NHW, n = 15 (37%)]. A majority of patients had relapsed disease (73%); however BW were more likely to have de novo metastatic disease compared to NHW (38% vs 7%, p = 0.03). Twenty-seven (66%) patients received atezolizumab and 14 (34%) were treated with pembrolizumab. Of the 23 (56%) patients with NGS testing, alterations in TP53, PIK3CA, and BRCA were seen in 23 (100%), 5 (31%), and 1 (6%) patient, respectively. Median tumor mutational burden was similar between BW and NHW (5 vs 7, p = 0.8). BW had numerically lower median PDL-1 (SP142) compared to NHW (1% vs 2%, p = 0.5). Rates of immune and dose-limiting chemotherapy-related adverse events were similar between BW and NHW (Table). There were no differences in ICI response between groups, though BW had fewer complete responses and a shorter median PFS compared to NHW. Median OS was 12 months in BW compared to 28 months in NHW (p = 0.1). Conclusions: Our experience with real-world use of this regimen showed that BW had fewer complete responses and a trend towards worse OS compared to NHW. BW had numerically lower median PDL-1 expression compared to NHW, suggesting further investigation of biomarkers, potentially by Race, are needed to better identify responders to ICI in mTNBC. [Table: see text]
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2022.40.16_suppl.1074
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2022
detail.hit.zdb_id:
2005181-5
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