P1.08-019 Risk Factors and Survival of Occult N2 Lymph Node Metastasis in NSCLC Patients with Clinical N0-1 Diagnosed by Preoperative PET-CT

Abstract

Accurate staging of NSCLC for N2 lymph node metastasis is crucial for prognosis and optimal therapy. Suggestion of occult mediastinal lymph node metastasis could help physicians for decision making of staging and management. This study was aimed to know risk factors and survival for occult N2 lymph node metastasis in NSCLC patients with clinical N0 and N1 diagnosed by preoperative PET-CT. This study was evaluated NSCLC patients with clinical N0-1 who underwent R0 lung resection with complete lymphadenectomy. Clinicopathological factors such as tumor size, tumor location, tumor laterality, histology, and FDG uptake were analyzed to delineate risk factors. Overall survival was analyzed. Between November 2005 and December 2014, the incidence of N2 lymph node metastasis was 13.3% (22 patients of 166). The risk factors for pN2 were central located tumor (p<0.001), larger tumor size on CT (p=0.038), and high SUV on PET (p=0.001). Patients having risk factor of central tumor had shorter survival, significantly (p<0.001). The central located tumor, larger tumor size on CT, and high SUV of primary tumor were predictable factors for N2 lymph node metastasis in clinical N0-1 NSCLC. Therefore, these factors may help determined whether to enforce cN0-1 patients to do mediastinal staging selectively.