The prognostic analysis of lung cancer patients with occult malignant pleural disease at thoracotomy

Background: This study aims to determine the clinicopathological prognostic factors for occult malignant pleural disease (MPD) that were first detected in patients with non-small cell lung cancer (NSCLC) at thoracotomy and to assess the outcome of surgical intervention. Methods: A total of 120 thoracotomy-patients with MPD were examined. The Kaplan-Meier test estimated survival curves, and Cox regression analysis was performed to validate the risk factors picked. In assessing surgical intervention, clinical and pathological parameters were matched by propensity score matching (PSM). Results: With a median follow- up of 34 months, the 5-year overall survival of 120 patients was 28.0%. Multivariate analyses showed male (P=0.044), advanced T stages (P<0.001), advanced N stages (P=0.02), pleural invasion in image (P=0.005), pleural effusion (P=0.027), surgical intervention (P=0.008) and EGFR status (P=0.003) were independent predictors of survival. The 5-year survival rate and median survival time (MST) for 21 patients with lobectomy and pleurectomy were 71.6% and undefined, compared with 25.6% and 40.0 months in 46 patients with sublobectomy. When 53 patients only subjected to open-close surgery, their 5-year survival rate and MST were 23.4% and 30.2 months. After PSM, both 21 patients were included in lobectomy with the pleurectomy group and sublobectomy /open-close group. The overall survival of lobectomy with the pleurectomy group was better than the control group (P=0.046). Conclusions: Age, stage, pleural invasion, pleural effusion, surgical intervention, and EGFR status affected the prognosis of the MPD patients first diagnosed at thoracotomy. Selective surgery gives better recovery, and additional studies are needed.