Current understanding and approach to well differentiated lung neuroendocrine tumors: an update on classification and management

Abstract

Neuroendocrine tumors (NETs) are rare neoplasms that can arise from any tissue. They are classified based on embryonic gut derivative (i.e. foregut, midgut and hindgut) with midgut tumors being the most common (e.g. gastrointestinal NET). The second most common category of NETs is that which arises from the lung. In fact, 25% of primary lung cancers are NETs, including small cell lung cancer (SCLC), which comprises 20% of all lung cancers. The remaining 5% are large cell neuroendocrine cancer (LCNEC, 3%), typical carcinoids (TCs, 1.8%), and atypical carcinoids (ACs, 0.2%). The less common TCs/ACs are well differentiated lung NETs. Their incidence has been increasing in more recent years and although these tumors are slow growing, advanced disease is associated with poor survival. There have been advances in classification of lung NETs that have allowed for more appropriate management upfront. They are cured by surgical resection when disease is limited. However, advanced and metastatic disease requires medical therapy that is ever changing and expanding. In this review, the aim is to summarize the current understanding and classification of well differentiated lung NETs (i.e. TCs and ACs), and focus on recent updates in medical management of advanced disease, along with a brief discussion on potential future discoveries.

A single-institution retrospective analysis of metachronous and synchronous metastatic bronchial neuroendocrine tumors

“…Studies of therapies in the advanced or metastatic lung carcinoid setting have been limited to retrospective analyses and some small prospective studies (6,(38)(39)(40). Recent articles reviewed the current standard of care and recent advances in therapy for bpNETs (41)(42)(43)(44).…”

Incidental Findings on Myocardial Perfusion SPECT Images

“…6). Although pulmonary carcinoids are a common type of neuroendocrine tumor, they comprise only 1%-2% of all lung tumors (8).…”

Imaging in Pancreatic Neuroendocrine Tumors

“…8 All these are epithelial neoplasms with predominant neuroendocrine differentiation. 9 Imaging characterization of these lesions depends on whether the tumor is functional or nonfunctional…”