Assessment of the proliferation marker Ki-67 by endoscopic ultrasound guided-Fine Needle Aspiration (EUS-FNA) in pancreatic endocrine tumors: A comparative analysis with histology of the surgical specimen

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Introduction: Assessment of the proliferative index by Ki-67 immuno-labelling is an important prognostic parameter for the biologic behavior of digestive neuroendocrine tumors, usually established on the histological specimen obtained after surgery or macro-biopsy. However, small pancreatic endocrine tumors (PET) are more and more often recognized by CT/MRI and diagnosed by EUS. The value of Ki-67 labelling index (Ki-67-LI) on fine needle aspiration (FNA) is not well-established in this setting, although regularly assessed.

Aim(s): 1: To correlate Ki-67-LI obtained on cytological material to the corresponding surgical specimen in patients with operated pancreatic endocrine tumors; 2: To evaluate the prognostic value of Ki-67-LI obtained by FNA on progression-free or disease-free survival (PFS or DFS) on the whole study population.

Materials and methods: Retrospectively, between 1996 and 2009, 44 cases of PET with a EUS-FNA in their work-up were retrieved. Among them, 34 were operated and pathology was available for 26. Two blinded pathologists evaluated Ki-67-LI quantitatively, both on cytological (100-950 cells) and histological (2,000 cells) material for each patient. The study included 23 women and 21 men with a median age of 58 years (range: 28-85). For operated tumors, the recently proposed 2006 ENETS TNM classification was applied: We observed seven stage 1 tumors, 10 stage 2, five stage 3 and four stage 4. Tumoral grading according to the same classification identified 16 Grade 1 (Ki-67≤2%), seven grade 2 (Ki-67 3-20%) and three grade 3 (Ki-67>20%).

Conference: 7th Annual ENETSConcerence (2010)

Presenting Author: Borbath I

Authors: Bernard V, Weynand B, Jouret-Mourin A, Gigot J, Hubert C,

Keywords: pancreatic endocrine tumor, endoscopic ultrasound, Ki-67, prognosis,