Thoracoscopic Assessment of Pleural Tumor Burden in Patients with Malignant Pleural Effusion Prognostic and Therapeutic Implications

Background: Malignant pleural effusion (MPE) is encountered at an advanced stage of disease progression and often heralds a poor prognosis. The most reliable predictive factor of survival in such patients is the primary tumor. Thoracoscopy is often performed for accurate diagnosis and/or thoracoscopic talc insufflation as a therapeutic modality. It remains unknown whether pleural tumor burden, as visualized on thoracoscopy, has potential prognostic value. The objective of this study was to determine the prognostic accuracy of pleural tumor extent and localization (parietal, visceral, or diaphragmatic involvement), as assessed during medical thoracoscopy. Methods: Medical records of all patients who underwent thoracoscopy for suspicion of MPE between 2001 and 2008 at a tertiary care referral hospital were reviewed. Patients were included if pleural metastatic invasion was confirmed on tissue biopsy and survival status ascertained. Results: Four hundred twenty-one patients underwent diagnostic or therapeutic medical thoracoscopy at our referral center. Among them, 122 had confirmed metastatic pleural spread, but survival data were lacking in 15. Primary tumor consisted of non-mall cell lung cancer in 56, breast cancer in 23, melanoma in eight, and other malignancies in 20. Median survival of the entire population was 9.4 months. On univariate analysis, the following variables were significantly associated with reduced median overall survival: pleural metastatic melanoma, age less than 60 years, bloody MPE, extensive pleural adhesions, and widespread visceral pleural nodules (p < 0.05). On multivariate analysis, only melanoma as a primary tumor, pleural fluid appearance and extent of pleural adhesions remained independent and significant predictors of survival. Conclusion: No significant association was found between the extent or localization of pleural tumor burden and overall survival.