Comparison of the Masaoka-Koga staging and the International Association for the Study of Lung Cancer/the International Thymic Malignancies Interest Group proposal for the TNM staging systems based on the Chinese Alliance for Research in Thymomas retrospective database

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

doi:10.21037/jtd.2016.03.22

Comparison of the Masaoka-Koga staging and the International Association for the Study of Lung Cancer/the International Thymic Malignancies Interest Group proposal for the TNM staging systems based on the Chinese Alliance for Research in Thymomas retrospective database

J Thorac Dis. 2016 Apr;8(4):727-37. doi: 10.21037/jtd.2016.03.22.

Authors

Guanghui Liang¹, Zhitao Gu¹, Yin Li¹, Jianhua Fu¹, Yi Shen¹, Yucheng Wei¹, Lijie Tan¹, Peng Zhang¹, Yongtao Han¹, Chun Chen¹, Renquan Zhang¹, Keneng Chen¹, Hezhong Chen¹, Yongyu Liu¹, Youbing Cui¹, Yun Wang¹, Liewen Pang¹, Zhentao Yu¹, Xinming Zhou¹, Yangchun Liu¹, Yuan Liu¹, Wentao Fang¹; Members of the Chinese Alliance for Research in Thymomas

Affiliation

¹ 1 Department of Thoracic Surgery, Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou 450008, China ; 2 Department of Thoracic Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China ; 3 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 ; 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, Beijing Cancer Hospital, Beijing 100142, China ; 11 Department of Cardiothoracic Surgery, Changhai Hospital, Shanghai 200433, China ; 12 Department of Thoracic Surgery, Liaoning Cancer Hospital, Shenyang 110042, China ; 13 Department of Thoracic Surgery, First Affiliated Hospital of Jilin University, Changchun 130021, China ; 14 Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610041, China ; 15 Department of Thoracic Surgery, Huashan Hospital, Fudan University, Shanghai 200032, China ; 16 Department of Esophageal Cancer, Tianjin Cancer Hospital, Tianjin 300060, China ; 17 Department of Thoracic Surgery, Zhejiang Cancer Hospital, Hangzhou 310022, China ; 18 Department of Thoracic Surgery, Jiangxi People's Hospital, Nanchang 330006, China.

Abstract

Background: To compare the predictive effect of the Masaoka-Koga staging system and the International Association for the Study of Lung Cancer (IASLC)/the International Thymic Malignancies Interest Group (ITMIG) proposal for the new TNM staging on prognosis of thymic malignancies using the Chinese Alliance for Research in Thymomas (ChART) retrospective database.

Methods: From 1992 to 2012, 2,370 patients in ChART database were retrospectively reviewed. Of these, 1,198 patients with complete information on TNM stage, Masaoka-Koga stage, and survival were used for analysis. Cumulative incidence of recurrence (CIR) was assessed in R0 patients. Overall survival (OS) was evaluated both in an R0 resected cohort, as well as in all patients (any R status). CIR and OS were first analyzed according to the Masaoka-Koga staging system. Then, they were compared using the new TNM staging proposal.

Results: Based on Masaoka-Koga staging system, significant difference was detected in CIR among all stages. However, no survival difference was revealed between stage I and II, or between stage II and III. Stage IV carried the highest risk of recurrence and worst survival. According to the new TNM staging proposal, CIR in T1a was significantly lower comparing to all other T categories (P<0.05) and there is a significant difference in OS between T1a and T1b (P=0.004). T4 had the worst OS comparing to all other T categories. CIR and OS were significantly worse in N (+) than in N0 patients. Significant difference in CIR and OS was detected between M0 and M1b, but not between M0 and M1a. OS was almost always statistically different when comparison was made between stages I-IIIa and stages IIIb-IVb. However, no statistical difference could be detected among stages IIIb to IVb.

Conclusions: Compared with Masaoka-Koga staging, the IASLC/ITMIG TNM staging proposal not only describes the extent of tumor invasion but also provides information on lymphatic involvement and tumor dissemination. Further study using prospectively recorded information on the proposed TNM categories would be helpful to better grouping thymic tumors for predicting prognosis and guiding clinical management.

Keywords: Thymoma; prognostic grouping; staging.