In patients with treatment-sensitive cancers, does systemic anti-cancer therapy increase the chance of malignant pleural effusion control?

Background: Malignant pleural effusions (MPE) often require multiple pleural interventions. Observational data suggest that systemic anti-cancer therapy (SACT) may effectively control MPE in treatment-sensitive cancers (TSC). Aim: The aim of this study was to determine whether SACT was associated with higher rates of MPE control in patients with TSC. Methods: Patients were identified from a prospective, single-centre, UK-based cohort study between 05/11/08-08/06/17. Cancers classified as TSC are outlined in Table 1. The independent variable was receipt of SACT and the primary outcome control of MPE. Time-to-event analysis was used, adjusted for tumour type, MPE size, non-expandable lung and pleurodesis attempts. Results: 127 eligible patients were identified (Table 1). MPE control occurred more often in patients who received SACT than those who did not (50/112; 44.6% vs 1/15; 6.7%, p=0.005). SACT was an independent predictor of MPE control (adjusted OR 13.1, p=0.045). Other factors associated with MPE control included having lymphoma (OR 5.1, p=0.049) and undergoing pleurodesis (OR 5.3, p=0.001). Discussion: These data suggest that SACT may be an effective first-line treatment of MPE in patients with TSC, particularly lymphoma. Confounding was possible, though, and a randomised trial would determine whether SACT precludes the need for definitive pleural intervention in these patients.