Immunohistochemistry identifies E-cadherin, N-cadherin and focal adhesion kinase (FAK) as predictors of stage I non-small cell lung carcinoma spread through the air spaces (STAS), and the combinations as prognostic factors.

Background: Spread through air spaces (STAS) is one of the multiple modes of lung cancer dissemination, yet its molecular and clinicopathological characterization remains poorly studied. This study aimed to investigate the effect of adhesion molecule expression levels on the incidence of STAS and postoperative recurrence in stage I lung cancer patients undergoing radical resection.

Methods: 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 retrospectively using immunohistochemistry in patients undergoing radical resection for stage I non-small cell lung cancer (NSCLC). Patients were categorized into four groups based on adhesion molecule expression levels: "low/low", "high/low", "low/high", and "high/high", and the group with the lowest recurrence-free probability (RFP) was defined as high risk. Associations between those adhesion molecules' expression levels and STAS were determined by using the Chi-squared test and logistic regression model. RFP 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 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. We found that low expression of E-cadherin, high expression of N-cadherin and FAK, and males were independent predictors of higher incidence of STAS. Multivariate Cox analysis showed that tumors with low E-cadherin/high N-cadherin, low E-cadherin/high FAK, and high N-cadherin/high FAK expression were important predictors of recurrence in patients with stage I lung carcinoma. In addition, females and high N-cadherin/high FAK were associated with a high risk of recurrence in patients with STAS.

Conclusions: E-cadherin, N-cadherin, and FAK are predictors of STAS occurrence in stage I NSCLC, and their combinations are prognostic factors. The discovery of these molecular markers provides clinicians with a reliable means that may help in the early identification of individuals with a higher risk of recurrence in lung cancer patients, targeting personalized treatment plans such as aggressive adjuvant therapy or closer follow-up.