Somatostatin receptor tissue distribution in lung neuroendocrine tumours: a clinicopathologic and immunohistochemical study of 218 'clinically aggressive' cases.
BACKGROUND
The management of pulmonary neuroendocrine tumours (NETs), with special reference to clinically aggressive carcinoids and large-cell neuroendocrine carcinomas (LCNECs), is poorly standardised and data about somatostatin receptor (SSTR) expression or therapeutic guidelines for somatostatin analogue administration are still debated.


METHODS
A series of 218 lung NETs [24 metastatic typical carcinoids (TCs), 73 atypical carcinoids (ACs), 60 LCNECs and 61 surgically resected small-cell lung carcinomas] were investigated for SSTR types 2A and 3 tissue distribution using immunohistochemistry, in correlation with clinicopathologic parameters, outcome, scintigraphy and treatment.


RESULTS
SSTRs were heterogeneously distributed with a significant progressive decrease from low- to high-grade forms. SSTR type 2A was strikingly overexpressed in metastatic TCs as compared with ACs and clinically benign TCs. SSTR tissue immunolocalization correlated with octreotide scintigraphy in 20 of 28 cases.


CONCLUSIONS
The immunohistochemical determination of SSTRs, with special reference to low-grade/intermediate-grade tumours, may assist the clinical approach with somatostatin analogue-based diagnostic and therapeutic procedures in clinically aggressive pulmonary NETs.
Righi
L
L
Division of Pathology. Electronic address: luisella.righi@unito.it.
Volante
M
M
Division of Pathology.
Tavaglione
V
V
Division of Pathology.
Billè
A
A
Division of Thoracic Surgery, Department of Clinical & Biological Sciences, University of Turin at San Luigi Hospital, Orbassano, Torino.
Daniele
L
L
Department of Biomedical Sciences and Human Oncology, University of Turin, Torino.
Angusti
T
T
Division of Nuclear Medicine, Department of Clinical & Biological Sciences, University of Turin at San Luigi Hospital, Orbassano, Torino.
Inzani
F
F
Department of Pathology and Laboratory Medicine, Division of Pathology, University of Parma, Parma.
Pelosi
G
G
Diagnostic Histopathology Unit, European Institute of Oncology, University of Milan, Milan, Italy.
Rindi
G
G
Department of Pathology and Laboratory Medicine, Division of Pathology, University of Parma, Parma.
Papotti
M
M
Division of Pathology.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D002276:Carcinoid Tumor / Q000378:metabolism* / Q000556:secondary; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000378:metabolism* / Q000556:secondary; D011379:Prognosis; D017481:Receptors, Somatostatin / Q000378:metabolism*; D055752:Small Cell Lung Carcinoma / Q000378:metabolism* / Q000556:secondary; D014018:Tissue Distribution; D055815:Young Adult
D014408:Biomarkers, Tumor; D017481:Receptors, Somatostatin; C103631:somatostatin receptor 3; C093733:somatostatin receptor 2