Abstract 2732: Multiplex immunoanalysis of cytokines in EUS-FNAs and in plasma to detect pancreatic cancer

Abstract

Abstract Background: Endoscopic ultrasound fine needle aspirations (EUS-FNAs) are frequently used to diagnose masses of the pancreas. Immunohistochemical analysis aids in the separation by FNAs of chronic inflammatory diseases, benign tumors, and neuroendocrine tumors from adenocarcinomas. Multiplex immunoassay of plasma or EUS-FNAs for cytokines might also be useful diagnostically. Method: An extra EUS-FNA was obtained from consented patients for research; these were stored at −80°C neat or in 100 μl of 10% DMSO in RPMI 1640. EUS-FNAs were randomly selected from the collection to include 61 cases of pancreatic adenocarcinoma, 14 (all) neuroendocrine tumors, and 6 (all) benign pancreatic diseases. These EUS-FNAs were thawed in lysis buffer, diluted to samples with 500 μg/ml total protein and analyzed in duplicate using a 27 plex kit for IL-1b, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-15, IL-17, Eotaxin, FGF Basic, G-CSF, GM-CSF, IFN-g, IP-10, MCP-1, MIP-1a, MIP-1b, PDGFbb, RANTES, TNFα, and VEGF. Samples of unprocessed plasma matching the EUS-FNAs were also analyzed for these same 27 cytokines and in non-matching plasma for 8 cytokines. Results: The analysis by Luminex technology of 8 cytokines in the plasma of 100 patients with pancreatic cancer (PANCA) or of 33 patients suspected, but not having PANCA, indicated that il-8 (P<0.006) might be useful in the separation of patients with PANCA. Il-2, il-4, il-6, il-10, IFN-γ, TNF GM-CSF were not useful. Based on EUS-FNA, those cytokines which appear most useful in separating diagnostic groups are interleukin 1 receptor antagonist (il- 1ra), interleukin 6, and interleukin 8 (P=0.012 or less). When these three cytokines were optimally combined, there is a clear separation of PANCA from benign/inflammatory conditions plus neuroendocrine tumors P<2.1E-06. Conclusions: These results suggest that the use of multiplex immunoassays of blood and of EUS-FNAs might be useful in the diagnosis of pancreatic cancer. (1) For plasma levels only, il-8 is more strongly correlated with cancer versus benign conditions or neuroendocrine tumors; thus il-6 and the combination of il-6 with il-8 does not improve the identification of cancer. (2) There is no correlation between plasma levels of il-6 and il-8 with il-6 and il-8 levels from EUS-FNAs. (3) For EUS-FNA, the il-1ra has the strongest correlation with cancer P<8.2E-06 followed by il-8 P<1.7E-05. The il-8 levels but not the il-6 levels add to the separation of cancer by il-1ra. (4) Combining il-8 plasma levels with il-8 levels by FNA only slightly improves the correlation. Sponsored in part by the Early Detection Research Network (EDRN) Reference Laboratory at UAB (5U24CA086359-10) and the Pancreatic SPORE at UAB (5P20CA101955-05). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2732.