A recent publication from the World Health Organization (WHO) has identified that neuroendocrine neoplasms are a large and diverse group of tumors that require a common classification framework. This is an important step forward for patients with neuroendocrine tumors.
This paper, focussing on the pathology of these tumors, has finally consolidated the information about neuroendocrine neoplasms with a uniform approach. In the past, these diseases were handled by general pathologists or, when specialists were available, they were diagnosed by specialists in different fields of pathology. This resulted in disparate criteria for diagnosis and classification of tumor that arise in different sites of the body. There was a wide gulf between NETs arising in classical endocrine glands (for example pituitary, parathyroid or thyroid) and those arising in other sites where non-endocrine tumors are far more common, such as lung, bowel or pancreas. The criteria applied to NETs of the various non-endocrine organs are also very different; while there has been great progress in classifying NETs of gut and pancreas, lung pathologists were still using the terms “carcinoid tumor” and “atypical carcinoid tumor”.
This landmark paper has emphasized the similarities of neuroendocrine neoplasms throughout the body. It clarifies the importance of a single terminology for well differentiated NETs, and the importance of distinguishing the well-differentiated tumors from the far more aggressive neuroendocrine carcinomas (NECs) that have completely different behavior and underlying genetic abnormalities. It emphasizes that while NETs have some similar genetic underpinnings in their various sites, and that there is a common approach to treatment of these tumors, there is a need for more research to clarify prognostic biomarkers (such as Ki67) and to elucidate the common and distinct genetic and genomic factors underlying the different metastatic capacities of the various types of NETs.
Summary provided by CNETS Canada Scientific & Medical Advisory Board member and co-author of the paper, Dr. Sylvia Asa