Long-Term Survival Outcomes of Surgical Resection for Lung Adenocarcinoma with Intraoperatively Diagnosed Pleural Metastasis: Target Treatment Era.

Purpose: This study aimed to evaluate the clinical impact of main tumor resection on long-term survival compared with pleural biopsy alone in patients with lung adenocarcinoma who were intraoperatively diagnosed with pleural metastasis.

Materials and methods: A total of 176 patients with adenocarcinoma who had unexpected pleural metastasis detected during surgery from 2002 to 2021 were retrospectively analyzed. Each surgeon decided whether to perform main tumor resection or pleural biopsy alone.

Results: The patients were grouped based on the surgical approaches: main tumor resection (Resection group; n=83) and pleural biopsy only (O&C group; n=93). The Resection group had better overall survival (OS, 10-year survival: 27.9% vs. 9.4%; median survival: 68.3 vs. 36.6 months; p<0.01) and locoregional progression-free survival (10-year survival: 12.5% vs. 7.1%; median survival: 19.6 vs. 10.6 months; p<0.01) than the O&C group. Similar results were found for OS in patients who received tyrosine kinase inhibitors (TKIs) as first-line therapy (10-year survival: 49.2% vs. 15.0%; median survival: 72.2 vs. 45.4 months; p=0.03), patients who did not undergo TKIs treatment (10-year survival: 29.4% vs. 9.2%; median survival: 82.4 vs. 23.8 months; p<0.01), and patients with positive target gene mutation (10-year survival: 31.7% vs. 10.1%; median survival: 72.2 vs. 33.7 months; p<0.01). In multivariate analysis, pleural biopsy only (hazard ratio, 1.73; p=0.04) was a significant predictor of OS.

Conclusion: Main tumor resection can improve survival in patients with lung adenocarcinoma who had unexpected pleural metastasis during operation.