Synovial SarcomaThis is a story of two sarcomas, synovial and osteo sarcomas, and their differing genetic backgrounds.

Fifteen years ago or so, when checking the genes of synovial sarcoma, researchers discovered that almost all synovial sarcomas had the same genetic abnormality. From a gene standpoint this seemed almost simple. A gene jumped from one chromosome (the tenth) and combined with a gene from another chromosome (the eighteenth). This new genetic splice makes a new protein that appears to be very important in sustaining the growth of malignant synovial sarcoma.

OsteosarcomaFifteen years later research continues on identifying what pathways in the cell are affected by this new gene and exactly how it works. It has identified subtypes of synovial sarcoma, but so far none of this has led to a successful new treatment. And no one is talking about undoing the new gene and putting the two parts back where they belong. There is very basic research going on as to what caused the genes to jump in the first place.

Osteosarcoma on the other hand has a lot of genetic abnormalities, but not this abnormality. It appears to be an entirely different cancer, with many subtypes and from the gene standpoint as different as night and day from synovial sarcoma.

And a final note. The word synovial, comes from synovium, meaning the tissues lining joints. Since these tumors are of a type that when pieces are looked at under the microscope, and arise near or around joints, it was assumed they were “synovial” sarcomas. The current view is that they have nothing to do with synovium. Old knowledge replaced by new. Eventually there will be a new classification system for sarcomas.

 This article was written by RIS Board member, Dr. John Seymour, MD