Risk Factors for Lymph Node Metastasis and Surgical Scope in Patients With Early-Stage Non-Small Cell Lung Cancer: A Single-Center Study in China

Abstract Background It is difficult to determine the lymph node metastasis of patients with early-stage non-small cell lung cancer (NSCLC) before surgery. The purpose of this study is to investigate risk factors of lymph node metastasis in early-stage NSCLC, thereby to identify the surgical indications for lymph node dissection in early-stage NSCLC. Methods We conducted a retrospective study of patients with tumor size ≤ 30mm who underwent radical resection of NSCLC. Binary logistic regression analysis was applied to predict risk factors for lymph node metastasis, and subject operating characteristics (ROC) curve was used to evaluate the independent risk factors. Results Overall, 44 patients (6.8%) with early-stage NSCLC had lymph node metastasis. Factors of tumor consolidation diameter (p < 0.001) and preoperative serum carcinoembryonic antigen (CEA) level (p = 0.017) are independent risk factors lymph node metastasis in early-stage NSCLC. The ROC curve showed that the cut-off value of consolidation diameter was 16.5mm, and the area under the curve (AUC) was 0.825 (p < 0.001, 95% CI: 0.780–0.870); the cut-off value of serum CEA level was 1.765µg/L, AUC = 0.661( p < 0.001, 95% CI: 0.568–0.754). Moreover, 8 of 461 patients with tumor parenchyma ≤ 16.5mm had lymph node metastasis, and 36 of 189 patients with tumor parenchyma > 16.5mm had lymph node metastasis. Conclusion Tumor consolidation diameter and preoperative serum CEA are independent factors to predict early stage NSCLC. For patients with tumor parenchyma > 16.5mm, the probability of lymph node metastasis is higher and lobectomy plus lymph node dissection is recommended. For patients with tumor parenchyma ≤ 16.5mm, the probability of lymph node metastasis is lower and sublobectomy plus lymph node sampling is feasible.