Visceral pleural invasion predict a poor survival among lung adenocarcinoma patients with tumor size ≤ 3cm.

INTRODUCTION: The impact of visceral pleural invasion (VPI) on survival remains controversial for patients with early stage non-small cell lung cancer (NSCLC). This study investigated the survival status of VPI among patients with lymph node-negative lung invasive adenocarcinoma smaller than 3cm.

METHODS: We retrospectively reviewed 2537 consecutive patients with pathologic stage I lung invasive adenocarcinoma. All patients had received lobectomy and system lymph nodes resection. Patients were classified into 4 groups according to tumor size and visceral pleural invasion status. Disease-free survival (DFS) and overall survival (OS) were analyzed to evaluate survival difference between these groups.

RESULTS: 548 patients with VPI while 1989 patients without VPI were included in this study. For patients with tumor size ≤2cm, patients with VPI had significant worse DFS (HR,4.85; 95% CI, 2.98-7.91; p = .000) and OS(HR,3.52; 95% CI, 1.59-7.78; p = .002) compared with non-VPI group. For patients with tumor size between 2-3cm, patients with VPI had significant worse DFS (HR, 1.72; 95% CI, 1.16-2.55; p = .006) but no significant OS (HR, 1.31; 95% CI, 0.76-2.24; p = .330) compared with non-VPI group. For patients with VPI, there were no survival difference between tumor size 2-3cm group and ≤2cm group for both DFS(HR,1.02; 95% CI, 0.65-1.61; p = .939) and OS(HR,1.45; 95% CI, 0.71-2.97; p = .315).

CONCLUSIONS: VPI could predict a poor survival even for node-negative invasive lung adenocarcinoma patients with tumor size less than 3cm.