Malignant Pleural Effusion at Presentation in Patients with Small-Cell Lung Cancer

Abstract

Background: Malignant pleural effusion (MPE) is commonly seen in patients with non-small cell lung cancer. However, the prevalence of MPE at presentation in small-cell lung cancer (SCLC) is not reported and the clinical impact of MPE at presentation on patients with SCLC remains largely unknown. Objective: The objective of this study is to assess the occurrence rate of MPE and its prognostic implications at presentation in patients with SCLC. Method: We used the Surveillance Epidemiology and End Results (SEER) registry to extract data from patients with SCLC diagnosed between 2004 and 2014. The Kaplan–Meier method was used to estimate the overall survival and the Cox proportional hazard model was used to evaluate whether MPE was an independent risk for outcome. Results: Among the 68,443 patients with SCLC, MPE was present in 7,639 (11.16%). The probability of MPE was higher in older patients with larger tumors and mediastinal lymph node involvement at presentation. Median overall survival (3 vs. 7 months), estimated 1-year survival (17 vs. 30%), and 2-year survival (6 vs. 14%) were significantly lower in patients with MPE than without MPE, respectively (hazard ratio [HR] 1.46, 95% confidence interval [CI] 1.41–1.50, p< 0.001). MPE was also an independent factor for worse survival in multivariate analysis (HR 1.36, 95% CI 1.32–1.41, p < 0.001). Conclusions: MPE is common at presentation (11%) in patients with SCLC and may be associated with decreased survival. Additional studies are required to assess the treatment-adjusted survival rate in the setting of MPE.