Abstract
Background: lymph node metastasis is a poor prognostic factor for lung cancer; however, the risk of lymph node metastasis has not been clarified yet, so it is controversial to conduct systematic lymph node dissection for early lung cancer. Therefore, this study aimed to focus on analyzing the predictive factors for lymph node metastasis in patients with clinical stage IA3 lung adenocarcinoma.Methods: Our study group retrospectively analyzed all surgical patients admitted to our hospital from January 1, 2017 to June 2021, and these patients were considered having stage IA3 lung adenocarcinoma. A total of 334 patients underwent lobectomy combined with systematic lymph node dissection. Univariate and multivariate logistic regression analysis were adopted to predict the risk factors of lymph node metastasis.Results: Among the 334 patients eligible for this study, the overall mediastinal lymph node metastasis rate was 15.27%. There were 45 cases of N1 metastasis and 11 cases of N2 metastasis, 5 cases had both N1 and N2 metastasis at the same time. The patients were divided into three groups according to consolidation tumor ratio (CTR) values (<0.25, 0.25-0.5, >0.5). The lymph node metastasis rates in each CTR group were 1.8% (2/112), 11.7% (17/145) and 41.6% (32/77), respectively. The mediastinal lymph node metastasis rate in patients with carcinoembryonic antigen (CEA>5ng/ml) was 57.89% (22/38). The receiver operating characteristic curve (ROC) showed that the area under the curve (AUC) of CTR, pathological type and CEA were 0.790 [95% confidence interval (CI): 0.727 – 0.853，P<0.001]; 0.800（95% CI:0.735–0.865，P<0.001）;0.682（95% CI: 0.591–0.773, P<0.001）;respectively. Multivariate regression analysis showed that these listed factors were significantly correlated with lymph node metastasis of clinical stage IA3 lung adenocarcinoma: CEA [Odds Ratio (OR)=3.05, P=0.016], CTR 0.25 to 0.5 (OR=14.12, P<0.017), CTR>0.5 (OR=7.75, P=0.015), micropapillary adenocarcinoma (OR=15.704, P<0.001), and solid adenocarcinoma (OR=8.971, P=0.001).Conclusions: CEA (>5ng/ml), histologic subtype and CTR (>0.25) are important predictors of lymph node metastasis in clinical stage IA3 lung adenocarcinoma, systematic lymph node dissection should be the prior choice for patients with clinical stage IA3 incorporated with risk factors. The lymph node dissection method in stage IA3 should be alternative from those in stage IA1 and IA2.
Risk Factors for Lymph Node Metastasis in Clinical Stage IA3 Lung Adenocarcinoma Patients
