Research Article|Articles in Press

Prognostic factors and role of postoperative radiotherapy in surgically resected thymomas

Open AccessPublished:March 02, 2023DOI:
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      To investigate the prognostic factors and role of postoperative radiotherapy (PORT) for surgically-resected thymomas.


      A total of 1,540 patients with pathologically-confirmed thymomas undergoing resection between 2000 and 2018 were retrospectively identified from the Surveillance, Epidemiology, and End Results database. Tumor was re-staged as local (limited to thymus), regional (invasion to mediastinal fat and other neighboring structures), or distant stage. Disease-specific survival (DSS) and overall survival (OS) were estimated by the Kaplan-Meier method and Log-rank test. Adjusted hazard ratios with 95% confidence intervals (HR, 95%CI) were calculated by cox proportional hazards modeling.


      Tumor stage and histology were independent predictors of both DSS (regional: HR, 3.711, 95%CI, 2.006-6.864; distant: HR, 7.920, 95%CI, 4.061-15.446; type B2/B3: HR, 1.435, 95%CI, 1.008-2.044) and OS (regional: HR, 1.461, 95%CI, 1.139-1.875; distant: HR, 2.551, 95%CI, 1.855-3.509; type B2/B3: HR, 1.409, 95%CI, 1.153-1.723). For patients with regional stage and type B2/B3 thymomas, PORT was associated with better DSS after thymectomy/thymomectomy (HR, 0.268, 95%CI, 0.099-0.727), but the association was not significant after an extended thymectomy (HR, 1.514, 95%CI, 0.516-4.44). In patients with lymph nodal metastases, those who received PORT (HR, 0.372, 95%CI, 0.146-0.949), chemotherapy (HR, 0.843, 95%CI, 0.303-2.346), or both (HR, 0.296, 95%CI, 0.071-1.236) had a better OS.


      Extent of invasion and tumor histology were independent predictors of worse survival following surgical resection of thymoma. Patients with regional invasion and type B2/B3 thymoma who undergo thymectomy/thymomectomy may benefit from PORT, while patients with nodal metastases may benefit from multi-modality treatment including PORT and chemotherapy.

      Graphical abstract



      (TETs) (Thymic epithelial tumors), (SEER) (Surveillance, Epidemiology, and End Results), (NCI) (National Cancer Institute), (OS) (Overall survival), (DSS) (Disease-specific survival), (PORT) (postoperative radiotherapy), (TNM) (tumor-node-metastasis), (ICD) (International Classification of Diseases), (IASLC) (International Association for the Study of Lung Cancer), (ITMIG) (International Thymic Malignancy Interest Group), (NCCN) (National Comprehensive Cancer Network), (ESMO) (European Society for Medical Oncology), (NOS) (not otherwise specified), (HR) (Hazard ratio), (CI) (Confidence intervals)