J Chest Surg.  2022 Apr;55(2):126-142. 10.5090/jcs.21.124.

An Overview of Surgical Treatment of Thymic Epithelial Tumors in Korea: A Retrospective Multicenter Analysis

• Lee JO
• Lee GD
• Kim HR
• Kim DK
• Park SI
• Cho JH
• Kim HK
• Choi YS
• Kim J
• Shim YM
• Park S
• Park IK
• Kang CH
• Kim YT
• Park SY
• Lee CY
• Lee JG
• Kim DJ
• Paik HC
• for the Korean Association for Research on the Thymus

• KMID: 2528149
• DOI: http://doi.org/10.5090/jcs.21.124

Abstract

Background
Thymic epithelial tumors (TETs) are rare, and information regarding their surgical outcomes and prognostic factors has rapidly changed in the past few decades. We analyzed surgical treatment practices for TETs and outcomes in terms of overall survival (OS) and freedom from recurrence (FFR) during a 13-year period in Korea.
Methods
In total, 1,298 patients with surgically resected TETs between 2000 and 2013 were enrolled retrospectively. OS and FFR were calculated using the Kaplan-Meier method and evaluated with the log-rank test. Prognostic factors for OS and FFR were analyzed with multivariable Cox regression.
Results
A total of 1,098 patients were diagnosed with thymoma, and 200 patients were diagnosed with thymic carcinoma. Over the study period, the total number of patients with surgically treated TETs and the proportion of patients who underwent minimally invasive thymic surgery (MITS) increased annually. The 5-year and 10-year survival rates of surgically treated TETs were 91.0% and 82.1%, respectively. The 5-year and 10-year recurrence rates were 86.3% and 80.0%, respectively. The outcomes of surgically treated TETs improved over time. Multivariable Cox hazards analysis for OS, age, tumor size, and Masaoka-Koga stage were independent predictors of prognosis. The World Health Organization classification and tumor-node-metastasis (TNM) staging were also related to the prognosis of TETs.
Conclusion
Surgical treatment of TETs achieved a good prognosis with a recent increase in MITS. The M-K stage was the most important prognostic factor for OS and FFR. The new TNM stage could also be an effective predictor of the outcomes of TETs.

Keyword

Thymic epithelial tumor; Thymectomy; Video-assisted thoracic surgery