Pretreatment Serum C-Reactive Protein Levels Predict Benefit From Multimodality Treatment Including Radical Surgery in Malignant Pleural Mesothelioma

Abstract

To evaluate the prognostic and predictive relevance of pretreatment serum C-reactive protein (CRP) in malignant pleural mesothelioma (MPM) patients. MPM is a rare but aggressive disease with poor treatment outcome. Therapeutic decision is challenging, and predictive biomarkers for better treatment stratification are urgently needed. Clinical data, including survival and pretreatment CRP levels, were retrospectively collected from 115 patients with histologically proven MPM. Patients with any evidence for infectious disease were excluded. The association between CRP levels and survival was analyzed using Cox models adjusted for clinical and pathological factors. Median pretreatment CRP of all patients was 1.19 mg/dL (range: 0.00-22.62 mg/dL). Patients with elevated CRP levels (≥1 mg/dL; n = 62, 53.9%) had a significantly shorter overall survival compared with those with normal CRP (hazard ratio [HR] 2.81, 95% confidence interval [CI] 1.82-4.33; P < 0.001). In multivariate survival analyses, elevated CRP was confirmed as an independent prognostic factor in MPM (HR 2.07, 95% CI 1.23-3.46; P = 0.01). Most interestingly, we observed a significant interaction between CRP and treatment modality (P < 0.001). Among patients with normal CRP levels, radical tumor resection within multimodality therapy was associated with distinctly prolonged overall survival when compared with treatment protocols without surgery (HR 7.26, 95% CI 3.40-15.49; P < 0.001). In contrast among patients with elevated CRP, no survival benefit was achieved by radical surgery within multimodality approaches (HR 0.911, 95% CI 0.53-1.58; P = 0.74). Our results suggest that multimodality regimens including radical resection increase survival selectively in MPM patients with normal pretreatment serum CRP levels.