In a pathology review from the phase 3 JCOG0802/WJOG4607L trial, tumor spread through air spaces (STAS) emerged as a strong adverse marker in early-stage non-small cell lung cancer (NSCLC) irrespective of surgical approach. Among 640 eligible cases (487 nonmucinous adenocarcinoma), STAS was present in 35.5% and was linked to significantly shorter relapse-free survival (hazard ratio [HR] 2.05; 95% confidence interval [CI], 1.46–2.87) and overall survival (HR 2.34; 95% CI, 1.70–3.21; both P<.001). Multivariable analyses confirmed STAS as independently prognostic for relapse-free survival (P<.001) and overall survival (P=.004), with higher local recurrence rates in STAS-positive tumors. By surgery type, STAS predicted worse relapse-free survival after both lobectomy (P=.007) and segmentectomy (P=.006), and worse overall survival after lobectomy (P=.019).
In the nonmucinous adenocarcinoma subset, histologic grade 3 strongly correlated with STAS (P<.001) and poorer outcomes (relapse-free survival [RFS]: HR 2.98; overall survival [OS]: HR 2.80; both P<.001). On multivariable analysis, both STAS (P=.021) and grade 3 (P=.001) independently predicted shorter RFS, while only grade 3 remained significantly associated with OS (P=.002). Investigators concluded that STAS should be incorporated into surgical planning and post-operative surveillance strategies.
Reference: The ASCO Post Staff. STAS Predicts Prognosis in Early NSCLC Regardless of Surgical Approach. The ASCO Post. Published September 12, 2025. Accessed September 16, 2025. https://ascopost.com/news/september-2025/stas-predicts-prognosis-in-early-nsclc-regardless-of-surgical-approach/
