Genetics of the malignant progression of astrocytoma.

The tendency of human cancers to progress towards a more malignant state over time is a well described biological phenomenon. Recent investigations elucidating the genetic nature of malignancy and the possible mechanisms responsible for this evolution have suggested that a sequential pathway may exist whereby a cell population accumulates a nested set of genetic aberrations which endow it with the ability to overwhelm other populations and dominate the tumor. Human astrocytomas are a dramatic case in point, where specific genetic events of amplification and deletion are seemingly related to the stages of malignancy. The identification of these aberrations represents the first stage in the dissection of the temporal process of this cancer. Its augmentation with functional analyses will likely allow a fuller genetic description of in vivo transformation.