Current immunotherapy for thymic epithelial tumors: a narrative review.

Abstract

Background and objective: Thymic epithelial tumors (TETs) are the most common neoplasm of the prevascular mediastinal compartment and are characterized by their rarity and variable clinical presentation. The present study aimed to explore the current management of patients with TET with a special focus on immunotherapy for advanced disease.

Methods: Relevant studies published between 1981 and 2024 were searched in PubMed using search terms "Thymoma", "Thymic cancer", "Myasthenia gravis", "Radiation therapy", "Surgery", and "Immunotherapy".

Key content and findings: The International Thymic Malignancy Interest Group and the International Association for the Study of Lung Cancer established the tumor-node-metastasis (TNM) staging system for TET based on an overall survival (OS) analysis of a retrospective international database. While complete surgical resection is the mainstay for resectable TET, there are currently no clear guidelines on systemic treatments for advanced TET because of the complexity, rarity, and heterogeneity of this disease and the lack of in vivo and in vitro models. With the development of immunotherapy, the application of the anti-programmed cell death-1 (anti-PD-1) antibody is expanding and includes TET. Clinical trials on immune checkpoint inhibitors (ICIs) are ongoing, and the acceptable clinical efficacy of the anti-PD-1 antibody for TET has been reported. On the other hand, there have been reports of a heightened frequency of severe immune-related adverse events (irAEs) in TET.

Conclusions: ICIs have the potential for patients with TET. The benefit-toxicity ratio of ICI treatment needs to be carefully evaluated for those patients.