Neuroblastoma in southern Africa: epidemiological features, prognostic factors and outcome

We retrospectively analysed the epidemiological features and the importance of biochemical, histological and genetic parameters in predicting survival in 14 Namibian and 34 South African children treated for neuroblastoma (NB) from 1983 to 1997. Curative treatment consisted mainly of total (13%) or partial (44%) resection after chemotherapy (cyclophosphamide and doxorubicin x6 courses or carboplatin, etoposide, epirubicin and cyclophosphamide x6 courses). Localized radiotherapy with curative intent was given to 33% of patients. The male:female ratio was 0.9. The median age was 18 months (range 1-116) and was comparable in white, black and mixed ethnic patients. Primary disease was located in the abdomen (75%), thorax (15%), pelvis (5%) or elsewhere (5%). Evans stage distribution was: stage I, 2%; stage II, 19%; stage III, 21%; stage IV, 50%; and stage IVS, 8%. Stage III/IV disease was more common in black than in white children (p = 0.0001). Urinary vanillyl mandelic acid was elevated in 63% of those tested. Survival after 5-163 months' follow-up was 90% for stages I and II combined (median 2983, range 798-4661 days), 51% for stage III (median 367, range 61-5001 days), 6% for stage IV (median 227, range 20-4379 days) and 50% for stage IVS (median 532, range 54-1543 days). All seven children with para-spinal tumours survived. Individual factors associated with significantly poorer survival were elevated serum lactate dehydrogenase (p < 0.001), Joshi histological risk categorization adapted for age (p = 0.039), n-myc amplification (p = 0.006) and diploidy or tetraploidy (p = 0.006). All seven children with serum ferritin exceeding 149 ng/ml at the time of diagnosis died and survival was 33% in children with 1p deletion and 67% in those without, but the numbers were too small to achieve significance. These findings confirm the benefit of simple biochemical tests and histology in identifying those who are likely to respond favourably to conventional chemotherapy and surgery. Supportive genetic tests on formalin-fixed paraffin-embedded tumour tissue contributed to predicting outcome in 21 patients.