The role of postoperative radiotherapy for stage I/II/III thymic tumor-results of the ChART retrospective database

Qianwen Liu; Zhitao Gu; Fu Yang; Jianhua Fu; Yi Shen; Yucheng Wei; Lijie Tan; Peng Zhang; Yongtao Han; Chun Chen; Renquan Zhang; Yin Li; Keneng Chen; Hezhong Chen; Yongyu Liu; Youbing Cui; Yun Wang; Liewen Pang; Zhentao Yu; Xinming Zhou; Yangchun Liu; Jin Xiang; Yuan Liu; Wentao Fang; Members of the Chinese Alliance for Research in Thymomas

doi:10.21037/jtd.2016.03.28

The role of postoperative radiotherapy for stage I/II/III thymic tumor-results of the ChART retrospective database

J Thorac Dis. 2016 Apr;8(4):687-95. doi: 10.21037/jtd.2016.03.28.

Authors

Qianwen Liu¹, Zhitao Gu¹, Fu Yang¹, Jianhua Fu¹, Yi Shen¹, Yucheng Wei¹, Lijie Tan¹, Peng Zhang¹, Yongtao Han¹, Chun Chen¹, Renquan Zhang¹, Yin Li¹, Keneng Chen¹, Hezhong Chen¹, Yongyu Liu¹, Youbing Cui¹, Yun Wang¹, Liewen Pang¹, Zhentao Yu¹, Xinming Zhou¹, Yangchun Liu¹, Jin Xiang¹, Yuan Liu¹, Wentao Fang¹; Members of the Chinese Alliance for Research in Thymomas

Affiliation

¹ 1 Department of Thoracic Surgery, Guangdong Esophageal Cancer Institute, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, China ; 2 Department of Thoracic Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China ; 3 Department of Thoracic Surgery, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai 200080, China ; 4 Department of Thoracic Surgery, Affiliated Hospital of Qingdao University, Qingdao 266001, China ; 5 Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai 200032, China ; 6 Department of Endocrinology, Tianjin Medical University General Hospital, Tianjin 300052, China ; 7 Department of Thoracic Surgery, Sichuan Cancer Hospital, Chengdu 610041, China ; 8 Department of Thoracic Surgery, Fujian Medical University Union Hospital, Fuzhou 350001, China ; 9 Department of Thoracic Surgery, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China ; 10 Department of Thoracic Surgery, Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou 450008, China ; 11 Department of Thoracic Surgery, Beijing Cancer Hospital, Beijing 100142, China ; 12 Department of Cardiothoracic Surgery, Changhai Hospital, Shanghai 200433, China ; 13 Department of Thoracic Surgery, Liaoning Cancer Hospital, Shenyang 110042, China ; 14 Department of Thoracic Surgery, First Affiliated Hospital of Jilin University, Changchun 130021, China ; 15 Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610041, China ; 16 Department of Thoracic Surgery, Huashan Hospital, Fudan University, Shanghai 200032, China ; 17 Department of Esophageal Cancer, Tianjin Cancer Hospital, Tianjin 300060, China ; 18 Department of Thoracic Surgery, Zhejiang Cancer Hospital, Hangzhou 310022, China ; 19 Department of Thoracic Surgery, Jiangxi People's Hospital, Nanchang 330006, China ; 20 Depart

Abstract

Background: Postoperative radiotherapy (PORT) for thymic tumor is still controversial. The object of the study is to evaluate the role of PORT for stage I to III thymic tumors.

Methods: The Chinese Alliance for Research in Thymomas (ChART) was searched for patients with stage I to III thymic tumors who underwent surgical resection without neoajuvant therapy between 1994 and 2012. Univariate and multivariate survival analyses were performed. Cox proportional hazard model was used to determine the hazard ratio for death.

Result: From the ChART database, 1,546 stage I to III patients were identified. Among these patients, 649 (41.98%) received PORT. PORT was associated with gender, histological type (World Health Organization, WHO), thymectomy extent, resection status, Masaoka-Koga stage and adjuvant chemotherapy. The 5-year and 10-year overall survival (OS) rates and disease-free survival (DFS) rates for patients underwent surgery followed by PORT were 90% and 80%, 81% and 63%, comparing with 96% and 95%, 92% and 90% for patients underwent surgery alone (P=0.001, P<0.001) respectively. In univariate analysis, age, histological type (WHO), Masaoka-Koga stage, completeness of resection, and PORT were associated with OS. Multivariable analysis showed that histological type (WHO) (P=0.001), Masaoka-Koga stage (P=0.029) and completeness of resection (P=0.003) were independently prognostic factors of OS. In univariate analysis, gender, myasthenia gravis, histological subtype, Masaoka-Koga stage, surgical approach, PORT and completeness of resection were associated with DFS. Multivariate analysis showed that histological subtype (P<0.001), Masaoka-Koga stage (P=0.005) and completeness of resection (P=0.006) were independent prognostic factors for DFS. Subgroup analysis showed that patients with incomplete resection underwent PORT achieved better OS and DFS (P=0.010, 0.017, respectively). However, patients with complete resection underwent PORT had the worse OS and DFS (P<0.001, P<0.001, respectively).

Conclusions: The current retrospective study indicates that PORT after incomplete resection could improve OS and DFS for patients with stage I to III thymic tumors. However for those after complete resection, PORT does not seem to have any survival benefit on the whole.

Keywords: Thymic tumor; overall survival (OS); postoperative radiotherapy (PORT).