Profile of soluble factors in pleural effusions predict prognosis in mesothelioma

BACKGROUND: Pleural mesothelioma is a deadly asbestos induced cancer. Less than 10% of mesothelioma patients survive 5 years post diagnosis. However survival can range from a few months to a number of years. Accurate prediction of survival is important for patients to plan for their remaining life, and for clinicians to determine appropriate therapy. One unusual feature of mesothelioma is that patients frequently present with tumor-associated pleural effusions early in the course of the disease. OBJECTIVE: To study whether cells and molecules present in pleural effusions provide prognostic information for mesothelioma. METHODS: We profiled the cellular constituents and concentrations of 40 cytokines, chemokines and cellular factors (collectively “soluble factors”) involved in inflammatory and immune signalling pathways in pleural effusion samples from 50 mesothelioma patients. Associations with survival were evaluated by Cox proportional hazards regression methods. Results for the two soluble factors most significantly and independently associated with survival were validated in an independent set of samples (n= 51) using a separate assay system. RESULTS: Survival analysis revealed that IL8, IL2Ra (CD25) and PF4 were independent determinants of a more negative prognosis in mesothelioma patients, independent of other known prognostic factors. Lipocalin2 and IL4 were associated with better prognosis. CONCLUSIONS: This study demonstrates that pleural effusions rich in a range of soluble factors are associated with poor prognosis. These findings will enhance our ability to prognosticate outcomes in mesothelioma patients.