Risk Factors for Lymph Node Metastasis in Stage pT1 Invasive Lung Adenocarcinoma.

Objective: To analyze the risk factors for lymph node metastasis (LNM) in patients with stage pT1 lung adenocarcinoma to select a more appropriate surgical option.

Methods: In this retrospective study, 294 patients with postoperative pathologically confirmed stage pT1 invasive lung adenocarcinoma were collected and divided into two groups according to whether they had mediastinal or hilar LNM. Patient tumor imaging, pathological features and gene mutations were analyzed, and risk factors that might predict LNM were derived via univariate and multivariate logistic analyses. LNM-related variables were screened by Boruta and least absolute shrinkage and selection operator regression analysis.

Results: Among the 294 patients, 45 (15.3%) had positive mediastinal or hilar lymph nodes. There were no significant differences between the two groups in terms of sex, age, or underlying disease. The difference in the percentage of solidity between the two groups was significant, with the higer percentage group showing a more significant difference. The results of multivariate logistic analysis revealed that a high percentage of solid components and wild-type epidermal growth factor receptor (EGFR) were risk factors for LNM. The nomogram for predicting LNM included the consolidation tumor ratio, tumor size, micropapillary and EGFR, with an area under the curve of 93.4% (95% CI: 88.7-99.1) in the derivation cohort and 92.3% (95% CI: 84.6-99.9) in the validation cohort.

Conclusions: A high proportion of solid components and wild-type EGFR were risk factors for pT1 stage lung adenocarcinoma, suggesting that the choice of lung segmentectomy needs to be evaluated and selected more cautiously.