Circulating fibrinogen is a prognostic and predictive biomarker in malignant pleural mesothelioma

Background: To investigate the clinical utility of pretreatment plasma fibrinogen levels in malignant pleural mesothelioma (MPM) patients. Methods: A retrospective multicenter study was performed in histologically proven MPM patients. All fibrinogen levels were measured at the time of diagnosis and clinical data were retrospectively collected after approval of the corresponding ethics committees. Results: In total, 176 MPM patients (mean age: 63.5 years +/- 10.4 years, 38 females and 138 males) were analysed. Most patients (n = 154, 87.5%) had elevated (>= 390 mg dl(-1)) plasma fibrinogen levels. When patients were grouped by median fibrinogen, patients with low level (<= 627 mg dl(-1)) had significantly longer overall survival (OS) (19.1 months, confidence interval (CI) 14.5-23.7 months) when compared with those with high level (OS 8.5; CI 6.2-10.7 months). In multivariate survival analyses, fibrinogen was found to be an independent prognostic factor (hazard ratio 1.81, CI 1.23-2.65). Most interestingly, fibrinogen (cutoff 75th percentile per 750 mg dl(-1)) proved to be a predictive biomarker indicating treatment benefit achieved by surgery within multimodality therapy (interaction term: P = 0.034). Accordingly, only patients below the 75th percentile benefit from surgery within multimodality therapy (31.3 vs 5.3 months OS). Conclusions: Fibrinogen is a novel independent prognostic biomarker in MPM. Most importantly, fibrinogen predicted treatment benefit achieved by surgery within multimodality therapy.