Biology and novel therapeutics for neuroendocrine tumors of the lung.

Neuroendocrine (NE) tumors of the lung are a special class of tumors that include large cell neuroendocrine carcinoma (LCNEC), typical carcinoid (TC) tumor, atypical carcinoid (AC) tumor, and small cell lung cancer (SCLC). Even though they all have the same NE phenotype, these tumors can differ in their pathological characteristics, immunohistochemical patterns, molecular and cellular biology, clinical characteristics, response to various therapeutic modalities, and finally the ability to be molecularly targeted by novel therapeutics. In this review article, we will summarize the various characteristics of these specialized NE tumors, with particular emphasis on the biology with the potential for novel targeted therapies. As an example, SCLC is characterized by overexpression of receptor tyrosine kinases such as c-Kit, c-MET and Ret, and these can be targeted with small molecule inhibitors and various antibodies. Many of NE tumors are quite aggressive and arriving at targeted therapies would be a useful venue to pursue for a potential cure.