Prognosis, Survival, and Clinicopathological Characteristics of Small Cell Lung Cancer with Pleural Fluid

Objective: While malignant pleural effusion (MPE) is generally observed in non-small cell lung cancer (SCLC) patients, its prevalence in SCLC has not been reported. Methods: Patients over 18 who were admitted to our hospital between January 2015 and December 2019 and diagnosed with SCLC histologically were retrospectively studied. Demographic data, tumor location, tumor stage, pleural fluid characteristics, radiological findings, and overall survival were recorded from hospital records. Results: Our study included 59 patients (48 [81.4%] men and 11 [18.6%] women), with a median age of 67. Forty-seven (79.7%) patients had a history of smoking. The patients had median tumor standardized uptake values (SUV) max levels of 11.9, a tumor diameter of 6 cm, and a follow-up period of 7 months. Protein levels in pleural fluid of the metastasizing group were significantly higher than in the nonmetastatic group (P = 0.049). In the univariate model, age, N stage, pleural fluid glucose, and pleural fluid protein levels were found significantly efficient in predicting disease-free survival (P = 0.008, P = 0.001, P = 0.001, and P = 0.026, respectively). In the multivariate reduced model, N stage, pleural fluid glucose, and pleural fluid protein levels were found independent predictive factors for disease-free survival (P = 0.000, P = 0.000, and P = 0.009, respectively). Conclusions: MPE is common at presentation (11%) in patients with SCLC and may be associated with reduced survival. Additional studies are needed to assess the treatment-adjusted survival rate in the MPE setting.