A morphological and immunohistochemical study of the endoscopic ultrasound–fine-needle biopsy samples from solid pancreatic masses: a single center study

Objective: The purpose of this study was to present the experience of a single center on endoscopic ultrasound–fine-needle biopsy (EUS–FNB) of pancreatic solid tumors amenable to immunohistochemistry (IHC) assay. Patients, Materials and Methods: Inclusion criterion for this prospective study was identifying patients with pancreatic solid tumors, by means of imaging methods, from January 2018 to February 2020, within the Department of Gastroenterology, Emergency Clinical Hospital, Bucharest, Romania. All patients underwent EUS–FNB and the harvested tissue was sent to the Department of Pathology for histopathological (HP) diagnosis and IHC assessment if tumoral origin remained undetermined. Results: A total of 57 patients were ultimately selected to take part in our study. We performed immunohistochemical analysis based on the morphological diagnosis of the pancreatic tumors and assessed cytokeratin (CK)7, CK20, caudal type homeobox 2 (CDX2), MutL homolog 1 (MLH1), MutS homolog (MSH)2, MSH6, postmeiotic segregation 2 (PMS2) for all histopathologically uncertain pancreatic ductal adenocarcinoma (PDAC) and chromogranin A, synaptophysin, pan-CK AE1/AE3 for pancreatic neuroendocrine tumors (pNETs). Cox hazard regression was performed to identify the factors influencing the survival rate. In univariate analysis, patient survival time was significantly associated with stage, location, surgical management and CK7 positivity. Our data show a statistically significant predictive relationship between stage (regional or metastatic) and hazard for survival (p=0.015). Tumoral location in the tail (p=0.015) and radicality surgery (p=0.015) significantly decrease the survival of pancreatic cancer (PAC) patients. The presence of CK7 (p=0.015) significantly increases the survival of pancreas cancer patients. Conclusions: EUS–FNB has opened up a new path for pancreatic tumor diagnosis providing enough tissue for HP examination and IHC. A panel of several immunomarkers might aid in providing new therapies for PAC patients.