Retrospective analysis of tumor spread through air spaces (STAS) in non-small cell lung cancer (NSCLC) cases

Aim: Lung cancer is the leading cause of cancer-related mortality worldwide. Spread through air spaces (STAS) refers to tumor cells found within air spaces surrounding the main tumor mass and has been associated with poor prognosis. This study aimed to investigate the relationship between STAS positivity and clinical as well as pathological variables in operated non-small cell lung cancer (NSCLC) patients followed at our center. Material and Methods: Patients diagnosed with NSCLC who underwent surgery between January 2018 and May 2022 at our institution were retrospectively analyzed. The relationship between clinical and pathological variables and STAS was investigated. Survival analyses were performed using the Kaplan-Meier method. Results: A total of 85 cases were evaluated within the scope of the study. STAS positivity was observed in 64.7% (n=55) of patients. Low-grade tumors were less common in the STAS positive group (p = 0.006). Regarding lymph node involvement, the frequency of N2 disease was significantly higher in STAS positive patients compared to STAS negatives (p = 0.003). The presence of lymphovascular invasion (LVI) was also significantly higher in the STAS positive group (p = 0.011). Although disease-free survival (DFS) and overall survival (OS) were numerically higher in the STAS negative group, the difference was not statistically significant. Conclusion: In this study, a significant association was found between STAS positivity and N2 disease, grade, and LVI in patients diagnosed with NSCLC. Although survival times were found to be lower in STAS positive patients compared to the STAS negative group, this difference did not reach statistical significance.