Early Diagnosis and Current Status of Immunotherapy for Thymic Carcinoma

Abstract

Thymic carcinoma (TC) is a rare and aggressive malignancy of the anterior mediastinum, with most patients diagnosed at advanced stages due to the absence of characteristic paraneoplastic syndromes. This review systematically synthesizes current evidence on early diagnostic modalities and immunotherapeutic strategies for TC. In diagnosis, imaging (CT, MRI), immunohistochemical markers (CD5/CD117), serum CYFRA 21-1 and circulating tumor DNA each offer distinct advantages, yet all are constrained by suboptimal sensitivity or specificity, and no single method currently enables reliable early detection. Therapeutically, immune checkpoint inhibitors (ICIs) as monotherapy yield a limited objective response rate (ORR) of approximately 18.4%, whereas ICI combined with chemotherapy, exemplified by the atezolizumab-carboplatin-paclitaxel regimen, could achieve an ORR of 56.2%, marking a substantial improvement. Notably, the incidence of grade 3-5 immune-related adverse events in TC patients (17.1%) is markedly lower than that in thymoma patients (58.3%), suggesting a more favorable safety profile for immunotherapy in TC. These findings underscore the transformative potential of chemo-immunotherapy as a first-line option for advanced TC, while also highlighting persistent challenges: the absence of validated predictive biomarkers, the limited efficacy of ICI monotherapy, and the lack of large-scale randomized controlled evidence. Future investigations should prioritize biomarker discovery, mechanistic exploration of the TC immune microenvironment, and long-term survival validation of combination regimens.