Usefulness of an immunohistochemical score in advanced pancreatic neuroendocrine tumors treated with CAPTEM or everolimus

Abstract Background Pancreatic neuroendocrine tumors are rare neoplasms for which few predictive and/or prognostic biomarkers have been validated. Our previous work suggested the potential of the combined expression of N-myc downstream-regulated gen-1 (NDRG-1), O6-methylguanine DNA methyltransferase (MGMT) and Pleckstrin homology-like domain family A member 3 (PHLDA-3) as prognostic factors for relapse and survival. Methods In this new multicenter study we evaluated immunohistochemistry expression in 76 patients with advanced PanNET who were treated with capecitabine-temozolomide or everolimus. Based on the immunohistochemistry panel, an immunohistochemistry prognostic score (IPS) was developed. Results In patients treated with capecitabine and temozolomide, low IPS was an independent prognostic factor for progression-free-survival and overall-survival. Similar findings were observed with highest IPS for overall-survival in patients treated with everolimus. Conclusion From our knowledge, it is the first time that a simple IPS could be useful to predict outcome for patients with metastatic pancreatic neuroendocrine tumors treated with everolimus or capecitabine and temozolomide.