Abstract 5872: Spatial immunophenotypes contribute to predict survival of triple-negative breast cancer assessed as Miller-Payne grade 4 and N0 after neoadjuvant therapy

Abstract

Abstract Objectives Some Miller-Payne 4 and N0 patients with triple-negative breast cancer (TNBC) after neoadjuvant chemotherapy (NACT) who had better survival should avoid treatment escalation. We aimed to identify these patients based on spatial distributions of immunophenotypes at initial diagnosis. Methods We retrospectively analyzed 272 TNBC patients with Miller-Payne grade 4/5 and N0 for tumor-infiltrating lymphocytes (TILs) in relation to clinical survival. The spatial immunophenotypes were analyzed by multiplexed ion beam imaging by time of flight combined with proteomic. A prognostic classifier was established by the random forest algorithm. Results The 5-year disease-free survival (DFS) was 63.8% for Miller-Payne 4 and 83.0% for Miller-Payne 5 (p=0.003), and overall survival (OS) was 71.0% and 85.5% respectively (p=0.007). High TILs were significantly associated with better DFS and OS in the Miller-Payne 4 patients (both p=0.016). Spatially, Miller-Payne 4 with good prognosis exhibited inflamed phenotype, with dominant CD8+ T cells on tumor center, few scattered CD68+ myeloid-derived cells far away from T cells, and deposit of increased lymphocyte activate molecules. Miller-Payne 4 with poor prognosis presented excluded phenotype, with few CD8+ T cells restricted to invasive margin, high density of CD14+CD68+CD11c+ myeloid cells with related molecules. These spatial immunophenotypes provided a good classifier model (AUC=0.975) to identify Miller-Payne 4 patients with different prognosis. We also observed similar signatures in Miller-Payne 5. Conclusion Spatial immunophenotypes may indicate the prognosis in TNBC assessed as Miller-Payne 4 and N0. Citation Format: Jianli Ma, Yuwei Deng, Dawei Chen, Xiaomei Li, Zhiyong Yu, Haibo Wang, Lei Zhong, Yingjie Li, Chengqin Wang, Xiaoping Zhou, Xiang Li, Qingyuan Zhang, Jinming Yu. Spatial immunophenotypes contribute to predict survival of triple-negative breast cancer assessed as Miller-Payne grade 4 and N0 after neoadjuvant therapy. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5872.