Abstract 5669: Differential prognosis of immune biomarkers in metastatic vs. early triple negative breast cancer (TNBC) settings

• Published in: Cancer research (Chicago, Ill.) Ill.), 2020-08, Vol.80 (16_Supplement), p.5669-5669
• Main Authors: Dupree, Kelly J., Chang, Ching-Wei, Thakur, Meghna Das, Wilson, Timothy R., Shames, David, Cameron, David, Molinero, Luciana
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2020-5669

Background: A pre-existing intratumoral immune response, as characterized by presence of tumor infiltrating lymphocytes or cytotoxic effector T cells, is linked to improved prognosis in early TNBC (eTNBC). Recent data in metastatic TNBC (mTNBC) suggest that immune rich tumors are not prognostic (Emens et al., SABCS 2018). Since different immune biomarkers were used across studies to make these observations, it is uncertain whether the T-cell immune biology has differential prognosis between eTNBC and mTNBC. The aim of this study was to evaluate the prognostic value of the T effector RNA gene signature (Teff), across two eTNBC and two mTNBC clinical studies using the same biomarker methodology. Methods: FFPE breast tumor samples from two adjuvant (BO20289 [n = 955] and NO17629 [n = 260]) and two front line metastatic (GO25632 [n = 62] and OAM4861G [n = 150]) TNBC clinical studies were evaluated for RNA gene expression by using customized Nanostring panels. Normalization was carried out across all 4 datasets combined, and Teff signature (CD8A, IFNG, PRF1, CXCL9 and CXCL10) values were generated using mean z-scores. Overall survival (OS) was evaluated in all the studies. Results: While levels of Teff were similar within the eTNBC studies (p = 0.43) and the mTNBC studies (p = 0.44), Teff score was significantly higher in eTNBC compared to the mTNBC studies (p