Immunological signature of patients with thymic epithelial tumors and Good syndrome: Correlation with clinical outcome

e20648 Background: Thymic epithelial tumors (TETs) are extremely rare and heterogenous neoplasms, associated with immune dysregulation. Recognized prognostic factors are TNM stage and the Masaoka-Koga classification. To the best of our knowledge, no study has been conducted to investigate the correlation between immunophenotype, level of cytokines, chemochines and clinical outcome in TETs patients. The aim of this study was to evaluate the correlation of immunological signature and long-term outcome in patients with TETs and Good Syndrome (GS). Methods: From May 2019 to October 2022, consecutive patients with TETs and GS, referred to the Rare Tumors Coordinating Center of Campania Region (CRCTR) of Federico II of Naples, were enrolled. The immunophenotype of monocytes, neutrophils, eosinophils, CD4+ T cells, CD8 + T cells, B-cells, NK cells and NKT-cells, T regulatory cells, and the evaluation of serum levels of cytokines, chemokines and growth factors were assessed using the 8-color immunophenotyping kit, Treg detection kit and pre-formed Kits by Bioplex multiplex, respectively. D’Agostino-Pearson normality test was used to evaluate whether the continuous data were normally distributed, and a two-tailed t-test for independent samples was used. Overall survival (OS) analysis was performed generating Kaplan-Meier curves and Cox Univariate models for the considered categorical stratifications. p-values < 0.05 were considered statistically significant. Results: A total of 24 consecutive TETs patients were included in the study: 13 (54.17%) patients were male and 11 (48.83%) were female, with a median age of 54.96 ± 9.6 years. Tumor histology included 20 thymoma, and 4 thymic carcinoma. Autoimmune diseases were found in 13 patients all of whom had thymoma. At the time of this analysis, 5 (20.83%) patients had no evidence of disease (NED) by imaging and were in follow-up, 17 (70.83%) patients were still alive. The analysis of leucocytes did not show statistically significant association with clinical outcome of TETs patients. On the contrary, a statistically significant correlation between serum concentration of IL-6 and OS was found with lower levels of IL-6 associated with poorer prognosis (HR: 9.654; p = 0.016). In addition, we found a statistically significant reduction of IL-2 (p = 0.04), IL-15 (p = 0.048), IL-5 (p = 0.03) and VEGF (p = 0.01) serum levels in patients with evidence of disease, as compared to NED patients. Conclusions: Overall, these findings suggest that measurement of IL-6 levels may be a useful parameter for identifying TETs patients with GS who have more aggressive diseases. Our preliminary data may be useful in the clinical management of this complex disease. Further studies are needed to better understand the pathophysiology and clinical implications of immunophenotype alterations in TETs patients.