Neuroendocrine tumors of the lung are
carcinomas characterized by different impact on the patients' prognosis, ranging from relatively indolent, low- to intermediate-grade
neoplasms with longer life expectation (i.e., typical and atypical
carcinoids) to very aggressive and poorly differentiated
neoplasms with dismal prognosis (i.e., large cell neuroendocrine
carcinoma and
small cell lung cancer). The standard treatment of typical or atypical
carcinoids is the complete surgical resection, whereas the role of radio-
chemotherapy in a multimodality treatment or for palliation remains controversial. Conversely, high-grade
neuroendocrine carcinomas are in primis treated by aggressive
combination chemotherapy, deserving surgical resection for uncommon low-stage
tumors. Since evidence has been accumulated that
neuroendocrine tumors of the lung are supplied with a wide array of
peptide receptors detectable on cell membranes by immunohistochemical methods, innovative strategies for diagnosis and radiometabolic
therapy have been devised to target these molecules for the correct clinical management of the patients. In this paper, the structural and functional aspects and the clinical applications of the detection of several
peptide receptors in pulmonary
neuroendocrine tumors will be reviewed, including
somatostatin receptors,
vasoactive intestinal peptide/pituitary
adenylate cyclase activating
peptide family
receptors, cholecystokinin /
gastrin receptors,
bombesin/
gastrin releasing peptide receptors,
neurotensin receptors,
substance P receptors, neuroepeptide Y
receptors, calcitonin/
calcitonin gene-related peptide receptors,
atrial natriuretic peptide receptors, glucagon-like-peptide-1
receptors, oxytocin receptors and
endothelin receptors. Only a detailed knowledge of the
peptide receptor distribution in these
tumor types, especially in uncommon
neoplasms such as atypical
carcinoids and large cell neuroendocrine
carcinomas, is pivotal for planning the most adequate interventions for the patients' diagnosis and
therapy.