Discrepancies between two alternative staging systems (European Neuroendocrine Tumor Society 2006 and American Joint Committee on Cancer/Union for International Cancer Control 2010) of neuroendocrine neoplasms of the pancreas. A study of 50 cases

The aim of our study was to identify and describe potential inconsistencies between two alternative staging systems of pancreatic neuroendocrine neoplasms (pNENs) – the European Neuroendocrine Tumor Society (ENETS) system (2006) and the American Joint Committee on Cancer/Union for International Cancer Control (AJCC–UICC) system (2010). To address this issue, we performed a retrospective clinico-pathological study of 50 cases of pNENs. We found 9 (18%) cases of ENETS/AJCC–UICC discrepancies regarding the primary tumor stage. They included 7 cases of T2/T3 disagreement and 2 cases of T3/T4 disagreement. In addition, we discussed the issue of potential T1/T2 discrepancy (however, we did not observe any such a case). Another inconsistency was related to the application of different stage prognostic groupings between both systems. In conclusion, the discrepancies between ENETS and AJCC–UICC staging systems for pNENs are relatively frequent and heterogeneous. We believe that they should be rigorously recognized. This is necessary for the evaluation of prognostic factors and the effectiveness of therapeutic options used in patients with pNENs.