On the Diagnostics of Neuroblastoma : Clinical and Experimental Studies

Neuroblastoma (NB) is one of the most common childhood cancers. Patients with low stage tumor have high survival rate, while those with advanced stage and/or unfavorable molecular biology have poor prognosis. A correct histopathological diagnosis, clinical stage, and identified genetic aberrations are crucial for treatment stratification according to current protocol. The tumor sample is obtained either by fine needle aspiration, cutting needle biopsy or open biopsy. NB exhibits neuroendocrine differentiation by showing immunoreactivity for chromogranin A (CgA), synaptophysin (syn), and neuron specific enolase (NSE) and 90% of the patients have increased levels of urine catecholamine metabolites. Experimental and clinical NB tumor samples were immunostained for somatostatin receptors (SSTRs) 1-5, somatostatin and CgA. Clinical tumor samples were also immunostained for syn, synaptic vesicle protein 2 (SV2), and vesicle monoamine transporter 1 (VMAT1) and 2 (VMAT 2). Blood samples from 92 patients were analyzed for level of CgA, NSE, and chromogranin B and compared with control groups. The urinary excretion of catecholamine metabolites was analyzed in samples collected at diagnosis. Clinical and laboratory data were extracted from patient records, including information on the diagnostic accuracy of ultrasound guided cutting needle biopsies (UCNB) and potential complications. We found that NB expressed the different SSTRs and that receptor 2 was the most frequently expressed before chemotherapy. Furthermore, NB tumors showed immunoreactivity for SV2, VMAT 1 and VMAT2 alongside CgA and syn. The immunoreactivity of SV2 was comparable to CgA and superior to syn. Patients with NB had higher blood concentrations of CgA and NSE compared with controls. Patients with advanced stage disease, MYCN amplification and 1 p deletion had higher concentrations of both CgA and NSE while only NSE was correlated to outcome with higher concentrations in the deceased patients. A high urinary excretion of homovanillic acid and dopamine were correlated to inferior outcome. UCNB were found to be safe and may provide all necessary diagnostic requirements for adequate therapy stratification according to current treatment protocols