Discrepancies between two staging systems (European-ENETS versus. American-AJCC) of neuroendocrine neoplasms of the pancreas: A study of 77 cases.

Abstract

318 Background: Pancreatic neuroendocrine tumors (pNETs) comprise a spectrum of neoplasm with variable biological behaviour and heterogeneous prognosis. The European Neuroendocrine Tumor Society (ENETS) and the American Joint Cancer Committee/Union for International Cancer Control (AJCC/UICC) TNM staging systems have been recently published. The aim of this study was to evaluate the consistency of both staging systems on outcomes for patients with pNETs. Methods: A retrospective clinico-pathological study of 77 consecutive patients with pNETs who were surgically treated from 1993 to 2014 was carried out. Results: The male to female ratio was 1.0 (38 men, 39 women); 56 tumors were non-functionating and 21 functionating. Most of the tumors were G1 (57) and 20 were classified as G2-G3. The AJCC/UICC stage was IA in 29 patients, IB in 14, IIA in 10, IIB in 7 and IV in 17. Meanwhile, according with the ENETS staging system was: stage I in 30, IIa in 14, IIb in 3, IIIa in 6, IIIb in 7 and IV in 17. We found 18 (23.3%) cases of ENETS - AJCC/UICC discrepancies regarding the primary tumor. They included 6 cases (33%) disagreement between IIA (T3 N0 M0) and IIIa (T4 N0 M0); and 7 cases (38.8%) between IIB (T1-T3 N1 M0) and IIIb (anyT N1 M0). Conclusions: The AJCC and ENETS TNM classification staging for pNETs provide meaninful prognostic value of long-term survival por patients with pNETs. The T staging discrepancies between AJCC/UICC and ENETS are relative frequent and should be strictly recognized.