Background: The clinical course of patients with malignant pleural effusions (MPEs) varies. The decision to undertake "definitive therapy" (pleurodesis, indwelling pleural catheter [IPC], or both) for MPEs is decided on a case-by-case basis. Identifying factors that predict definitive therapy may help guide early initiation of treatment. The aim of the study was to identify clinical, laboratory, and radiologic predictors associated with clinicians' prescription of definitive therapy for patients with MPE.
Methods: A multicenter, observational study was conducted over 55 months involving tertiary centers in Perth, Western Australia, Australia, and Lleida, Spain. Demographic, clinical, radiologic, biochemical, and histologic data and the treatments received were recorded. Logistic regression was performed to determine the variables useful for predicting definitive therapy.
Results: Data of 540 patients (365 from Perth and 184 from Lleida) were analyzed; 537 fulfilled the criteria of an MPE. Definitive therapy was used in 288 patients (53.6%): 199 received a pleurodesis and 89 an IPC. Univariate analysis of the combined cohort revealed that definitive therapy was more likely if the effusion has low pH, either as a continuous variable (OR, 30.30; P < .01) or with a pH cutoff of < 7.2 (OR, 2.09; P = .03); was large (> 50% of hemithorax) (OR, 2.75; P < .01); or was associated with mesothelioma (OR, 1.83; P < .01). Following multivariate analysis, low pleural pH (OR, 37.04; P < .01), large effusions (OR, 3.31; P < .01), and increasing age (OR 1.02, P = .01) were associated with the use of definitive therapy.
Conclusions: Patients with MPE with an effusion of low pleural fluid pH and large size on radiographs at first presentation are more likely to be treated with pleurodesis and/or IPC.