Angioimmunoblastic T cell lymphoma prognostic index in Asian population identifies low risk patients with unique gene expression profiles

Introduction: Angioimmunoblastic T cell Lymphoma (AITL) is a subtype of peripheral T cell lymphoma and prognosis is generally felt to be poor. Molecular characteristics differentiating good or poor risk AITL has not been identified. In our Asian multicentre study, we investigate the clinical prognostic factors affecting the outcomes of our AITL patients. We also interrogate the gene expression profiles in our patients to identify if there may be different immune and cell signalling signatures in different risk groups. Methods: Patients who were diagnosed with AITL and seen at National Cancer Centre Singapore, Singapore General Hospital and National University Cancer Institute, Singapore between June 1999 and December 2019 were retrospectively analysed. Relevant demographical and clinical characteristics were collected. Outcomes of interest were that of 5-year overall survival (OS) and 5-year progression free survival (PFS). Kaplan-Meier curves were plotted to estimate survival for each individual clinical parameter. Parameters found to be significant on univariate analysis were subsequently used in the generation of multivariate cox regression models. NanoString PanCancer IO360 panel (NanoString Technologies, Seattle, WA, USA) was used to interrogate gene expression on AITL FFPE tissue, following manufacturer’s protocol using the nCounter platform. Results: A total of 174 patients were identified. Median duration of follow up was 20.4 months. Median PFS and OS was 1.8 years and 5.6 years respectively. In multivariate analyses, Age >60, bone marrow Involvement, Total white cell count and serum Lactate dehydrogenase were associated with poorer PFS and OS. A prognostic index (AITL-PI) differentiated patients into low (0–1 factors, n = 64), moderate (2 factors, n = 59) and high-risk (3–4 factors, n = 49) subgroups with 5-year OS of 84.0%, 44.0% and 28.0% respectively (p < 0.0001). Gene expression studies performed in 23 patients found disparate immune cell type profiles and oncogenic signalling pathway signatures in the low risk as compared to the intermediate and high-risk groups. In the low risk group, neutrophilic, T-regulatory and Th-1 cell profiles were predominant whereas cytotoxic cell profile was predominant in the intermediate and high-risk groups. The low risk group was more active in the myeloid compartment, WNT, cytokine and chemokine, TGF-β and hedgehog signalling pathways whereas cytotoxicity, interferon and lymphoid compartment signalling signatures returned higher in the intermediate and high-risk groups. The research was funded by: NCCS Cancer Fund (Research) (NCCSCF-R-YR2021-JUN-SSD1), Tanoto Foundation Professorship in Medical Oncology, New Century Foundation Limited, Ling Foundation, Singapore Ministry of Health’s National Medical Research Council Research Transition Awards (TA21jun-0005 and TA20nov-0020), Large Collaborative Grant (OFLCG18May-0028), and Collaborative centre grant (TETRAD II). Keywords: Aggressive T-cell non-Hodgkin lymphoma, Diagnostic and Prognostic Biomarkers No conflicts of interests pertinent to the abstract.