Analysis of lymph node metastasis in 200 patients with non-small cell lung cancer

Background: Lymph node metastasis occurs although clinical stage IA is a relatively early stage for patients with non-small cell lung cancer (NSCLC). This study aimed to explore the influencing factors of lymph node metastasis. Methods: A total of 200 patients diagnosed with clinical stage IA NSCLC preoperatively from July 2014 to July 2016 were examined. Every patient underwent lobectomy and systematic lymph node dissection. Their clinicopathological characteristics and status of lymph node metastasis are analyzed. Results: The rates of both N1 and N2 lymph node metastasis increase with the increase in the tumor diameter. The N1 lymph node metastasis rate is 0%, 2.82%, and 9.52%, while the N2 lymph node metastasis rate is 0%, 4.23%, and 25.40% for pure ground-glass nodules, mixed ground-glass nodules (solid component <50%), and mixed ground-glass nodules (solid component >50%), respectively. The difference is statistically significant (P=0.000). Patients with squamous cell carcinoma have a relatively higher N1 lymph node metastasis rate comparing with patients with adenocarcinoma (P<0.05). Tumors locate in the inner half lobe (close to hilus) are prone to metastasize to lymph nodes (P=0.018). Multiple regression analysis shows that tumor diameter, solid component rate, and tumor location are relevant factors for lymph node metastasis. Conclusions: In patients with NSCLC, who have tumors smaller than 1 cm, pure ground-glass nodules, or tumors locate in the lateral half lobe, lymph node metastasis is rare and selective lymphadenectomy is considerable.