TURKISH JOURNAL OF ONCOLOGY 2020 , Vol 35 , Num 2
Factors Affecting Treatment and Prognosis in Thymomas: A Multi-Center Experience
Şule KARABULUT GÜL1,Hüseyin TEPETAM1,Şule KARAMAN2,Şimay GÜROCAK3,Esra KORKMAZ KIRAKLI4,İbrahim BABALIOĞLU5,Eda ERDİŞ6,Pelin ALTINOK7
1Department of Radiation Oncology, University of Health Sciences Lütfi Kırdar Kartal Training and Research Hospital, İstanbul-Turkey
2Department of Radiation Oncology, İstanbul University Faculty of Medicine, İstanbul-Turkey
3Department of Radiation Oncology, İnonu University Faculty of Medicine, İstanbul-Turkey
4Department of Radiation Oncology, Ege University Faculty of Medicine, İstanbul-Turkey
5Department of Radiation Oncology, Konya Education and Research Hospital, Konya-Turkey
6Department of Radiation Oncology, Cumhuriyet University Faculty of Medicine, İstanbul-Turkey
7Department of Radiation Oncology, Ümraniye Training and Research Hospital, İstanbul-Turkey
DOI : 10.5505/tjo.2020.2176 OBJECTIVE
Thymomas, a rare malignancy, are located in 95% anterior mediastinum. They are associated with paraneoplastic syndromes, especially myasthenia graves. Although many classifications are used considering the depth of invasion, presence of metastasis, predominant cell type, or immunohistochemical properties in staging, Masoaka classification is commonly used. Surgery is the most effective method in the treatment of thymoma, and neoadjuvant chemotherapy is recommended in advanced stages (III-IV). Adjuvant radiotherapy has proven efficacy in advanced and inoperable patients. In this study, we aimed to evaluate treatment outcomes and factors affecting prognosis in thymoma patients.

METHODS
Patients with thymoma who were included in this study voluntarily from seven centers between January 2002 and August 2018 were evaluated retrospectively.

RESULTS
Of the 158 patients with thymoma, 125 patients with complete data were included in this study. The mean age of the patients was 51.84 (18-84), and 72 were male. Myasthenia graves were present in 64 patients. One hundred thirteen patients were operated and 12 were inoperable. One hundred patients were stage 2, 9 were stage 3, and 16 were stage 4. In our study, 3-year survival was 84.4%, and 5-year survival was 74.9%; inoperable patients, surgical margin positivity, advanced disease and radiotherapy dose less than 50.4"Gy were found to be negative factors affecting survival. In patients with myasthenia graves (MG), survival was higher in patients with stage 2B and less. Survival was lower in epithelial type B3 and type C histologic types. Age, sex, and capsule involvement did not seem to affect survival.

CONCLUSION
Thymoma is a locally controlled disease with long survival and the results of our study are consistent with the literature. The number of patients should be increased to better define prognostic factors. Keywords : Radiotherapy; surgery; thymoma