Abstract PD5-12: Spatial mapping of the immune microenvironment in primary triple-negative breast cancer (TNBC) and association with neoadjuvant therapy response

• Published in: Cancer research (Chicago, Ill.) Ill.), 2019-02, Vol.79 (4_Supplement), p.PD5-12-PD5-12
• Main Authors: Telli, ML, Vinayak, S, Khododoust, MS, Gruber, JJ, Ford, JM, Sanchez, P, Banayan, N, Azimi, S, Tumeh, PC, Newman, AM, Alizadeh, AA
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.SABCS18-PD5-12

Background: Emerging data suggest that some patients with TNBC could benefit from the addition of immune-based therapy. This observation is in part due to the significant association between distinct tumor-infiltrating lymphocytes (TILs) and prognosis in TNBC. Efforts to comprehensively characterize the immune microenvironment of TNBCs are critically important to gain a better understanding of the immune landscape and how it influences response to both standard chemotherapy and immunotherapy. We previously assessed both stromal TILs (sTILs) and intraepithelial TILs (iTILs) from pre-treatment tumor samples from patients enrolled on a phase II study of neoadjuvant gemcitabine, carboplatin and iniparib (PrECOG 0105; NCT00813956). We found that both iTILS and sTILS significantly associated with pathologic response. Furthermore, we assessed a novel 'in silico flow cytometry' gene expression-based method, CIBERSORT, designed to assess overall immune content and deconvolute the relative levels of distinct leukocyte subsets in tumors. Specific leukocyte subsets significantly associated with pCR included activated memory CD4+ T cells, CD8+ T cells and M1 macrophages (all p