State-of-the art techniques for evaluating pancreatic neuroendocrine tumors
Expert opinion
A neuroendocrine tumor (NET) begins in the hormone-producing cells of the body’s neuroendocrine system, which is made up of cells that are a combination of hormone-producing endocrine cells and nerve cells. Neuroendocrine cells are found throughout the body in organs such as the lung as well as in the gastrointestinal tract, including the stomach, intestine, and pancreas.
Pancreatic neuroendocrine tumors (PNETs) or neoplasms (PNENs) are less common than the more familiar pancreatic adenocarcinoma, comprising about 5% of pancreas tumors. Pancreatic neuroendocrine tumors develop from cells in the pancreas called islet cells, the part of the pancreas that makes hormones that are released into the bloodstream to regulate certain body functions. While each type of tumor can spread (metastasize) from the pancreas to other organs, pancreatic neuroendocrine tumors usually spread over a period of years. PNETs grow at a far slower rate than pancreatic adenocarcinoma.
Diagnosis and follow-up of treatments by physicians in these cases are key for ensuring the best patient treatment.
In this review, Tetsuhide Ito details how PNENs are diagnosed and monitored in Japan. He provides a thorough inventory of techniques, from serum marker quantification to imaging. In the context of PNEN, he puts the emphasis on Chromogranin A and opens the door to new approaches for studying PNETs, such as AKT measurements and mTOR pathway investigations.
This type of pancreatic cancer has received a great deal of attention following the death of former Apple, Inc. CEO Steve Jobs, who had a pancreatic neuroendocrine tumor.
Discover a detailed panel of today’s methods and techniques for studying pancreatic NETs. Serum Chromogranin A measurement remains very useful. Always stay one step ahead!
Abstract
Several new developments have occurred in the field of pancreatic neuroendocrine neoplasm (PNEN) recently in Japan. First, the utility of chromogranin A (CgA), useful for the diagnosis and monitoring of the treatment response of neuroendocrine neoplasm (NEN), has been demonstrated in Japan. For PNEN diagnosis and treatment, grading and correct histological diagnosis according to the WHO 2010 classification is important. Regarding the histological diagnosis, the advent of endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has enabled correct pathological diagnosis and suitable treatment for the affected tissue. Furthermore, EUS-FNA also facilitates the assessment of the presence or absence of gene mutations. In addition, patients who have a well-differentiated neuroendocrine tumor (NET) showing a Ki-67 index of higher than 20 % according to the WHO 2010 classification, have also been identified, and their responses to treatment were found to be different from those of patients with poorly differentiated neuroendocrine carcinoma (NEC). Therefore, the concept of NET G3 was proposed. Additionally, somatostatin receptor type 2 is expressed in several cases of NET, and somatostatin receptor scintigraphy (111In-octreoscan) has also been approved in Japan. This advancement will undoubtedly contribute to the localization diagnosis, the identification of remote metastasis, and assessments of the treatment responses of PNEN. Finally, regarding the treatment strategy for PNEN, the management of liver metastasis is important. The advent of novel molecular-targeted agents has dramatically improved the prognosis of advanced PNEN. Multimodality therapy that accounts for the tumor stage, degree of tumor differentiation, tumor volume, and speed of tumor growth is required.