Elevated CRP levels predict poor outcome and tumor recurrence in patients with thymic epithelial tumors: A pro- and retrospective analysis

// Stefan Janik 1, 2 , Christine Bekos 1, 2 , Philipp Hacker 1, 2 , Thomas Raunegger 1, 2 , Bahil Ghanim 1 , Elisa Einwallner 3 , Lucian Beer 2, 4 , Walter Klepetko 1 , Leonhard Müllauer 5 , Hendrik J. Ankersmit 1, 2 and Bernhard Moser 1 1 Department of Thoracic Surgery, Division of Surgery, Medical University of Vienna, Vienna, Austria 2 Christian Doppler Laboratory for Diagnosis and Regeneration of Cardiac and Thoracic Diseases, Medical University of Vienna, Vienna, Austria 3 Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria 4 Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria 5 Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria Correspondence to: Bernhard Moser, email: bernhard.moser@meduniwien.ac.at Keywords: thymic epithelial tumors, thymoma, thymic carcinoma, CRP, prognosis Received: November 11, 2016      Accepted: April 12, 2017      Published: April 27, 2017 ABSTRACT Objective: Scarce information exists on the pathogenesis of thymic epithelial tumors (TETs), comprising thymomas, thymic carcinomas (TCs) and neuroendocrine tumors. C-reactive protein (CRP) increases during certain malignancies. We aimed to investigate the clinical relevance of CRP in patients with TETs. Results: Pretreatment CRP serum concentrations were significantly elevated in patients with TETs, particularly TCs and metastatic TETs. After complete tumor resection CRP serum concentrations were decreased ( p = 0.135) but increased significantly in case of tumor recurrence ( p = 0.001). High pretreatment CRP was associated with significantly worse 5- and 10-year freedom-from recurrence (FFR) ( p = 0.010) and was a negative prognostic factor for FFR (HR 3.30; p = 0.015). IL-6 (not IL-1β) serum concentrations were significantly elevated in patients with TETs but we did not detect CRP tissue expression in TETs. Materials and Methods: Pretreatment CRP serum concentrations were retrospectively analyzed from 128 surgical patients (1990–2015). In a subset of 68 patients longitudinal analysis of CRP was performed. Additionally, immunohistochemical tumor CRP expression and serum concentrations of interleukin (IL)-6 and IL-1β were measured. Conclusions: Hence, diagnostic measurement of serum CRP might be useful to indicate highly aggressive TETs and to make doctors consider tumor recurrences during oncological follow-up.