P3.01-31 Prognostic Factors in Patients with Resected Pathological N2 Non-Small Cell Lung Cancer

Abstract

Postoperative outcome for non-small cell lung cancer (NSCLC) patients with mediastinal lymph node metastasis is unfavorable even after complete resection. To identify the subgroup of NSCLC patients with mediastinal lymph node metastasis whom we recommend surgical treatment, we sought to investigate prognostic factors in these patients. We retrospectively reviewed NSCLC patients with pathologically identified mediastinal lymph node metastasis who underwent complete resection with systematic nodal dissection between 2000 and 2016. Demographic, clinical, and pathologic factors (sex, age, Brinkman index, performance status [PS], % vital capacity, forced expiratory volume % in 1 second, preoperative carcinoembryonic antigen [CEA], histological subtype, pathological tumor size, p-T factor [7th edition], pleural invasion, pulmonary metastasis, histological grade, number of positive mediastinal nodal stations [single station vs multiple stations], number of positive mediastinal lymph nodes [1-2 vs ≥3], epidermal growth factor receptor [EGFR] mutation status, and adjuvant chemotherapy) were analyzed using the log-rank test as univariate analyses and a Cox proportional hazards regression model for multivariate analyses to identify independent predictors of favorable overall survival (OS). Of the 54 eligible patients, 38 were male and 16 were female. The median age and CEA were 65 years and 5.3 ng/mL, respectively. Lobectomy, bilobectomy, and pneumonectomy were performed in 49/3/2 patients. Histological subtypes were adenocarcinoma in 29 patients, squamous cell carcinoma in 17, and others in 8. EGFR was inspected in 33 patients, and 10 patients were EGFR mutated. Adjuvant chemotherapy was performed in 26 patients. The details of adjuvant chemotherapy were cisplatin-based combination chemotherapy in 18 patients, and carboplatin-based combination chemotherapy in 8. The 3-year and 5-year OS were 64.9% and 44.7%, respectively, with a median follow-up period of 41 months. The preoperative CEA <5.3 ng/mL (HR: 0.2151) and undergoing adjuvant chemotherapy (HR: 0.3580) were identified as significant predictors of favorable OS. The 3-year and 5-year OS in patients with CEA <5.3 and ≥5.3 ng/mL were 88.3/70.8% vs 41.0/17.9%, respectively (p<0.001). The 3-year and 5-year OS in patients who underwent adjuvant chemotherapy or none were 75.3/70.3% vs 55.3/23.1%, respectively (p = 0.009). Even if NSCLC patients have mediastinal lymph node metastasis, favorable postoperative prognosis may be expected in patients with low preoperative serum CEA. Adjuvant chemotherapy should be considered in patients with mediastinal lymph node metastasis on pathological examination.