The CancerWeb Report, What's New In Cancer: June, 1996
Neuroblastoma

• Making sense of a perplexing tumor - Neuroblastoma is among the commonest solid tumors in children, but it is also the most perplexing. It is a frequent cause of death, but nearly 30% of patients have a favorable outcome despite many having widespread disease (Stage IVS) or tumor still remaining after surgery. Two special features of the tumor explain this: the ability to regress spontaneously, and the ability to lose malignant characteristics and mature to a benign tumor with non-life- threatening behavior. It is usually thought that neuroblastoma cells mature into a type of normal cell, the Schwann cell. The features determining tumor behavior are the amount of DNA in the tumor cell (ploidy; normal body cells are diploid, that is they have two DNA complements, sperm and ova have only one), the deletion of parts of the short arm of chromosome 1, and increased levels (amplification) of the N-myc oncogene. An article by researchers at the Children's Cancer Research Institute, Vienna, Austria, in the June 6, 1996, issue of the New England Journal of Medicine, described a study on 20 favorable neuroblastoma patients. There were no chromosome 1 deletions in their tumor cells. Neuroblast and maturing tumor cells were triploid (three complements) in 18 of 19 tumors, and pentaploid in (five complements) another tumor. Schwann cells, in contrast were diploid. The data indicated that neuroblastoma cells do not mature to become Schwann cells, and the authors suggest that the Schwann cells that intermingle in the tumor may be attracted there by secretions of the tumor cells, and may in turn release growth factors that cause the tumor cells to mature. (Ambros, NEJ Med 334:1505, 1996)

  Editor's Comment: - In an editorial in the same June 6, 1996 issue of the New England Journal of Medicine, Dr. Garrett Brodeur from the Children's Hospital in Philadelphia, comments on this article. He points out that in very young children, Schwann cells do not infiltrate the tumor, which may regress and die because they receive no supporting growth factor. He considers that there is need to identify these factors, in order to devise new treatment strategies based on them.