Abstract 607: PDL1 expression associated with triple negative breast ductal carcinomas in African American women

• Published in: Cancer research (Chicago, Ill.) Ill.), 2017-07, Vol.77 (13_Supplement), p.607-607
• Main Authors: Khan, Farhan, Kanaan, Yasmine, Ricks-Santi, Luisel J., Zafar, Rabia, Aymut, Hagos, Naab, Tammey
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2017-607

Background: Tumor cells avoid host immune response through expression of inhibitory T cell regulator, Programmed cell death ligand (PDL1).Our objective was to evaluate PDL1 expression by immunohistochemistry in the four major subtypes of breast carcinoma (Luminal A, Luminal B, HER2, and Triple Negative) in a population of 202 African-American (AA) women with other clinicopathological factors. Design: Tissue microarrays (TMAs) were constructed from FFPE tumor blocks from primary ductal breast carcinomas in 202 African-American females. Two separate 1 mm cores represented each case. Five micrometer sections were stained with rabbit monoclonal antibody against PDL1. The sections were evaluated for the percentage and intensity of membrane staining in both tumor and immune cells. Cut off was > 1%. Bivariate analysis was done via χ2 analysis and survivability data was calculated via the generation of Kaplan-Meier curves (SPSS v19). Statistical significance was assumed if p < 0.05. Results: PDL1 expression in only tumor cells, only immune cells and in combination was associated with ER negative (p