KI67 AGREEMENT BETWEEN EUS-GUIDED SAMPLING (EUS-FNA/FNB) AND SURGICAL SPECIMEN IN PANCREATIC NEUROENDOCRINE NEOPLASMS (PNEN)

Aims In pancreatic neuroendocrine neoplasms (pNEN) prognosis and therapeutic choices are mostly influenced by histological grading (G), based on Ki67 proliferative index: a correct pre-surgical evaluation is fundamental. The aim of the study is to evaluate the agreement of Ki67 and the respective grading, between EUS-guided sampling (FNA/FNB) and surgical specimen, in patients with pNEN.

Methods 68 patients who underwent surgery for pNEN, after EUS-guided sampling (47 FNA, 21 FNB), between 2005 and 2021, were retrospectively evaluated. EUS grading (eG) and surgical one (sG), measured according to Ki67 proliferative index (respectively eKi67 and sKi67), were compared.

Results Patients were mostly female (51%), with a mean age of 52±13.4 years; lesions were non-functioning in 79% and the mean size was 24.6±13.9 mm. In the whole population, eG-sG concordance was 69%; dividing the population according to the diameter of the lesion (<2 cm vs≥2 cm), concordance was 77.8% vs 63.2%, respectively; evaluating only lesions≥3 cm, the agreement decreased to 59.1%. EUS-sampling technique (FNA vs FNB) did not change the degree of agreement (71% vs 65%, p=0.77). The correlation between eKi67 and sKi67 was positive and moderate (tau=0.36, p<0.0001), slightly stronger in the FNB group than in the FNA one (tau=0.41, p<0.05 vs tau=0.32, p<0.05).

Conclusions In pNEN, Ki67 evaluation on the material obtained by EUS-guided sampling (both by FNA and FNB) shows a good agreement with Ki67 evaluated on surgical specimens; this agreement is even higher in small pancreatic lesions (<2 cm).

Publication History

Article published online:
14 April 2022