Biological variables in thoracic neuroblastoma: a Pediatric Oncology Group study

The prognosis for patients with neuroblastoma is related to the age and stage at time of presentation, as well as to the presence or absence of biological markers such as N-myc amplification and the degree of DNA ploidy. However, previous studies have shown that neuroblastoma in the thoracic site also is a favorable prognostic indicator, in that children with mediastinal neuroblastoma have a better survival rate, regardless of age or stage at time of presentation. This study was designed to evaluate the biological differences between thoracic and nonthoracic neuroblastoma with respect to N-myc amplification, DNA index as a measure of DNA ploidy, serum lactate dehydrogenase levels, and serum ferritin levels. Patients enrolled in the Pediatric Oncology Group study protocols for neuroblastoma were evaluated retrospectively, and log-rank analysis allowed the impact of each biological variable on survival to be determined for each cohort of patients. There were 1,335 neuroblastoma patients in the data base; 227 had thoracic-site neuroblastoma. Through analysis, it was apparent that patients with thoracic neuroblastoma have better survival rates than do their nonthoracic counterparts (P < .0001), and they are less likely to have N-myc amplification (P = .001), more likely to have an LDH level of less than 1,500 (P < .0001), and usually have a DNA index of greater than 1 (P < .003). Both thoracic and nonthoracic patients have low serum ferritin levels (86% of thoracic versus 83% of nonthoracic patients).(ABSTRACT TRUNCATED AT 250 WORDS)