Clinical significance of vanillylmandelic acid in neuroblastoma

ABSTRACT

Background: The second most common solid tumor in children is Neuroblastoma (NB). In about 90% of cases of NB, elevated levels of catecholamines or its metabolites are found in the urine or blood which includes Vanillylmandelic Acid (VMA) and Homovanillic Acid (HVA). Ferritin, Neuron-Specific Enolase (NSE) and Lactate Dehydrogenase (LDH) are commonly assessed in children suspected to have NB, and the levels of these markers are commonly used for differential diagnosis. Multiple clinical and imaging tests are needed for accurate patient assessment. Iodine 123(123I) Metaiodobenzylguanidine (MIBG) is the first-line functional imaging agent used in neuroblastoma imaging. To evaluate the utility of these marker present study was undertaken with 91 NB patients and 40 normal healthy control.Methods: The study comprised of blood samples and 24 hour抯 urine sample from 40 normal healthy subjects and 91 untreated patients with histologically proven Stage III and IV NB cases referred to our institute. Method used for NSE was Enzyme Immunoassay (Elisa), serum Ferritin was MIA, LDH-photometry and VMA by Column Chromatography.Results: Amongst the parameters studied VMA showed highest sensitivity (91%), specificity (94.4%) positive predictive value (97.8%) and 85% negative predictive value at the cut off levels of 7mg/ ml of creatinine as compared to other studied parameters.Conclusions: This study suggests that the detection of VMA in combination with routine histological examination, MIBG scan, serum NSE and LDH may improve the diagnosis of Neuroblastoma.