Epidemiological investigation of neuroendocrine differentiation in carcinomas: Focus on pancreatic and cholangiocarcinoma cohorts.

e16375 Background: Neuroendocrine differentiated (NED) occurs in various non-neuroendocrine organs and is associated with unique clinical profiles, disease progression, and poorer prognosis. However, global research on NED is scarce. To address this, our study utilized standardized detection methods to explore NED's prevalence in several solid tumors. This research aims to clarify NED pathological characteristics and prognostic significance, enhancing diagnostic and treatment approaches in clinical practice. Methods: Patients (18-75 years) with cancers including pancreatic, cholangiocarcinoma, gastric, colorectal, lung, breast, and prostate, were analyzed post-surgery at our hospital (January 2017- June 2018). Criteria for inclusion were normal organ function and no pre-surgery neoadjuvant therapy. Tumors were staged postoperatively using AJCC 8th criteria (stages I-III), followed by standard adjuvant chemotherapy. NED markers like Chromogranin A, Synaptophysin, and CD56 were detected in tumors via immunohistochemical staining. Results: Between January 2017 and June 2018, over 450 cases were enrolled. Initial analysis included 46 pancreatic cancer and 49 cholangiocarcinoma samples. NED markers were found in 11 (23.9%) of the pancreatic cancer patients, comprising 5 Syno (+), 10 ChrA (+), and 1 CD56 (+) cases. In cholangiocarcinoma patients, 12 (24.5%) expressed NED markers, including 4 Syno (+) and 11 ChrA (+) cases. Conclusions: This study reveals a significant occurrence of neuroendocrine differentiation in pancreatic cancer and cholangiocarcinoma. The notable prevalence of NED underscores its potential as a reference for tailoring clinical treatments. The association between NED and patient prognosis warrants further investigation.