Article
Author: Coindre, Jean Michel ; Pasquali, Sandro ; Rivoltini, Licia ; Romagosa, Cleofe ; Barisella, Marta ; Grignani, Giovanni ; Bague, Silvia ; Casiraghi, Elena ; Bergamaschi, Laura ; Beveridge, Robert Diaz ; Gronchi, Alessandro ; Lalli, Luca ; Collini, Paola ; Lopez-Pousa, Antonio ; Blay, Jean-Yves ; Sbaraglia, Marta ; Quagliuolo, Vittorio ; Vallacchi, Viviana ; Vergani, Barbara ; Stacchiotti, Silvia ; Dei Tos, Angelo Paolo ; Renne, Salvatore Lorenzo ; Brich, Silvia ; Martin-Broto, Javier ; Palmerini, Emanuela ; Casali, Paolo Giovanni
BACKGROUNDAnthracycline-based neoadjuvant chemotherapy (NAC) may modify tumour immune infiltrate. This study characterized immune infiltrate spatial distribution after NAC in primary high-risk soft tissue sarcomas (STS) and investigate association with prognosis.METHODSThe ISG-STS 1001 trial randomized STS patients to anthracycline plus ifosfamide (AI) or a histology-tailored (HT) NAC. Four areas of tumour specimens were sampled: the area showing the highest lymphocyte infiltrate (HI) at H&E; the area with lack of post-treatment changes (highest grade, HG); the area with post-treatment changes (lowest grade, LG); and the tumour edge (TE). CD3, CD8, PD-1, CD20, FOXP3, and CD163 were analyzed at immunohistochemistry and digital pathology. A machine learning method was used to generate sarcoma immune index scores (SIS) that predict patient disease-free and overall survival (DFS and OS).FINDINGSTumour infiltrating lymphocytes and PD-1+ cells together with CD163+ cells were more represented in STS histologies with complex compared to simple karyotype, while CD20+ B-cells were detected in both these histology groups. PD-1+ cells exerted a negative prognostic value irrespectively of their spatial distribution. Enrichment in CD20+ B-cells at HI and TE areas was associated with better patient outcomes. We generated a prognostic SIS for each tumour area, having the HI-SIS the best performance. Such prognostic value was driven by treatment with AI.INTERPRETATIONThe different spatial distribution of immune populations and their different association with prognosis support NAC as a modifier of tumour immune infiltrate in STS.FUNDINGPharmamar; Italian Ministry of Health [RF-2019-12370923; GR-2016-02362609]; 5 × 1000 Funds-2016, Italian Ministry of Health; AIRC Grant [ID#28546].