Systemic therapy for advanced thymic epithelial tumors: a narrative review of current evidence and perspectives

Thymic epithelial tumors (TETs), including thymoma and thymic carcinoma, are rare tumors. Although systemic therapy is commonly used for unresectable advanced or recurrent TETs, establishing robust evidence remains challenging. This narrative review summarizes current evidence and incorporates the latest clinical trial data, reporting outcomes separately for thymoma and thymic carcinoma whenever possible. We also highlight practical considerations relevant to clinical practice, including dosing strategies and toxicity management.

We searched PubMed and Google Scholar for prospective and retrospective original studies, meta-analyses, review articles, and case studies published up to November 2025 using terms including "thymoma", "thymic carcinoma", "thymic cancer", "thymic tumors", "thymic epithelial tumors", "chemotherapy", "systemic treatment", "immunotherapy", and "targeted therapy". Ongoing trials were identified via ClinicalTrials.gov and the Japan Registry of Clinical Trials. Retrospective studies enrolling fewer than 15 participants were excluded.

Systemic therapy for advanced TETs continues to include cytotoxic chemotherapy as a major component. In selected settings, particularly in thymic carcinoma, targeted therapy and immune checkpoint inhibitors (ICIs) represent additional active options. Emerging trials suggest that combination strategies may enhance efficacy. Novel drugs, including bispecific antibodies and antibody-drug conjugates, are being evaluated in ongoing phase II trials.

Despite the rarity of TETs, systemic treatment options have gradually expanded through the accumulation of evidence from small phase II studies. Future advances will require collaborative prospective trials to validate predictive biomarkers and support biomarker-enriched trial designs.