AB016. LA01. Impact of lymph node dissection on thymic malignancy: The Korean Association for Research on the Thymus (KART) Database Study

Abstract: Macroscopic and microscopic complete resection is the most important goal of surgical treatment in thymic malignancy. Radical thymectomy of thymic tumor and surrounding thymic tissue is the best way to achieve complete resection. It has been established as the standard treatment for thymic malignancy. However, whether additional lymph node dissection (LND) is necessary during thymectomy remains controversial because actual incidence of lymph node metastasis has not been well known and the therapeutic role of LND in thymic malignancies has not been established yet. Considering that LND is an important surgical procedure for staging and treatment in patients with many other solid malignancies, the need to establish the role of LND in thymic malignancies has been increasing. In 2013, the International Thymic Malignancy Interest group (ITMIG) and the International Association for Study of Lung Cancer (IASLC) proposed a new lymph node map and separate N stage in the eighth edition of TNM stage classification system for thymic malignancies. Systematic lymph node sampling in thymoma and LND in thymic carcinoma were suggested by ITMIG. However, evidence supporting routine LND during thymectomy is insufficient. To address the issue of LND in thymic malignancy, in this collaborative effort, authors of this study collected data on 1,597 patients who underwent surgical resection for primary thymic malignancies between 2000 and 2013 from the Korean Association for Research on the Thymus (KART) Database Study. The objective of the present study was to verify prognostic implications of lymph node metastases and the role of LND in thymic malignancies by retrospectively reviewing multi-center database in a large scale.

Keywords: Thymic malignancies; lymph node dissection (LND); oncologic outcome