e20020 Background: Spread through air spaces (STAS) is one of the many modes of lung cancer dissemination. Aberrant activation of epithelial-mesenchymal transition (EMT) has been associated with enhanced tumor cell migration and invasiveness, a process that is accompanied by a decrease in adhesion molecules that maintain contact between epithelial cells, leading to cell separation and increased cell motility. Our objectives were to investigate the effect of adhesion molecule expression levels on STAS occurrence and postoperative recurrence in patients undergoing radical resection for stage I lung carcinoma. Methods: We examined the association of adhesion molecules with STAS as the primary endpoint and the Disease-Free Survival (DFS) as a secondary endpoint. E-cadherin, P-cadherin, N-cadherin, focal adhesion kinase (FAK), epithelial cell adhesion molecule (EpCAM) neural cell adhesion molecule 1 (NCAM1), vascular cell adhesion molecule 1 (VCAM1), intercellular cell adhesion molecule-1 (ICAM-1) were analyzed by immunohistochemistry in patients undergoing radical resection for stage I lung carcinoma. Associations between those adhesion molecules expression levels and STAS were determined by using the chi-square test and logistic regression model. DFS was analyzed by using the log-rank test and Cox proportional risk model. Results: As of January 1, 2024, 12 of 60 patients undergoing radical resection for stage I lung carcinoma had a disease recurrence. All of 60 patients’ tissue specimens were retrospectively analyzed, and there were no significant differences between patients with STAS-positive(n=30) and STAS-negative(n=30) in baseline clinicopathologic features, except for histological growth patterns, and lymphovascular invasion.Higher incidence of STAS was significantly associated with low expression of E-cadherin (P=0.002), high expression of N-cadherin (P=0.018) and FAK (P=0.027), and males (P=0.026), independent of tumor size, age, and clinical stage. Multivariate analysis showed that STAS (P=0.025), low E-cadherin/high N-cadherin (P=0.038), low E-cadherin/high FAK (P=0.025), and high N-cadherin/FAK (P=0.003) were significantly correlated with a higher risk of recurrence. In addition, females (P=0.034), and high N-cadherin/FAK (P=0.032) were associated with a high risk of recurrence in patients with STAS. Conclusions: Low expression of e-cadherin, high expression of N-cadherin and FAK were independent predictors of higher incidence of STAS. Tumors with low E-cadherin/high N-cadherin, low E-cadherin/high FAK, and high N-cadherin/FAK expression were important predictors of recurrence in patients with stage I lung carcinoma. Additionally, high N-cadherin/FAK expression in tumors provides information about a higher risk of recurrence in STAS-positive stage I lung carcinoma.