• micrometastases
• neuroblastoma
• clinical significance
• minimal residual disease
• immunocytology
• reverse transcriptase polymerase chain reaction

The article by Burchill¹ in this issue casts light on major technical advances in our ability to detect ever smaller numbers of neuroblastoma cells in the peripheral blood and bone marrow of children with this disease. But what of the question posed in its title—is this clinically important? Intuitively, the answer would seem to be “yes, at least in some children”. The subject—detection of minimal quantities of tumour—and the technology are exciting; both are very “sexy”. However, the protracted and significantly less “sexy” process of answering that question in a meaningful way still remains. In which children, at what stage of treatment, using what discriminating threshold of tumour cells, detected in what tissue will these approaches accurately forecast outcome? Will that forecast be significantly more accurate than can currently be achieved by conventional staging or biological features? And, finally, will intervention in specific groups of children identified by these new techniques actually improve their outcome?

“It is in the design and execution of first rate clinical studies …