Where pathology meets molecular biology: N-myc amplification in human neuroblastoma as a paradigm for the clinical use of an oncogene alteration.

Increase of the dosage of cellular oncogenes by DNA amplification is a frequent genetic alteration of cancer cells. The presence of amplified cellular oncogenes is usually signalled by conspicuous chromosomal abnormalities, "double minutes" (DMs) or "homogeneously staining chromosomal regions" (HSRs). Some human cancers carry a specific amplified oncogene at high incidence. In neuroblastomas the amplification of N-myc has been found associated with aggressively growing cancers and is an indicator for poor prognosis. N-myc amplification is of predictive value for identifying neuroblastoma patients that require specific therapeutic regimens and for identifying patients that do not benefit from chemotherapy.