Risk factors for symptomatic malignant pleural effusion recurrence in patients with actionable mutations in advanced lung adenocarcinoma

BACKGROUND: Malignant pleural effusion (MPE) comes generally with high mortality and poor prognosis. Recurrence of symptomatic MPE is always accompanied by poor survival quality. In lung adenocarcinoma, researchers speculate whether patients with actionable mutation or without are applicable to different management models for MPE. Under the background of the high mutation probability and the encouraging therapeutic response in Asians, researches on the risk factors of MPE are in need. METHODS: This retrospective review included 343 metastatic lung adenocarcinoma patients with MPE. Recurrence was defined as recurrent symptomatic MPE requiring the second thoracentesis to relieve symptoms within 300 days after the first thoracentesis. Univariable and multivariable Cox regression analysis were utilized to investigate independent risk factors for MPE recurrence. RESULTS: Of the 343 patients involved, 139 experienced MPE recurrence within 300 days; 34.3% in 201 patients with actionable mutations and 51.2% in 129 patients without actionable mutations are in the recurrence. The median recurrence-free survival (RFS) of the group without mutations was 161 days. The median RFS of the other group with mutations was 300 days. Patients with actionable mutations showed a significantly lower hazard of MPE recurrence on univariate analysis. The multivariate analysis indicated that receiving targeted therapy after the first thoracentesis within 30 days, lower neutrophil-to-lymphocyte ratio (NLR) level, lower serum lactate dehydrogenase (s-LDH) level, and lower serum carcinoembryonic antigen (s-CEA) level were independent protective factors. In subgroup analysis, risk factors differed. Receiving targeted therapy after the first thoracentesis within 30 days remained an independent factor in the mutated patients. CONCLUSIONS: The findings herein indicated the characteristics of specific patients at high risk for MPE recurrence in lung adenocarcinoma. Patients with actionable mutations benefit more in MPE recurrence and could benefit from targeted therapy and active intrapleural management.