Molecular biological studies on soft tissue sarcomas

The new technologies of molecular biology have provided remarkable insights into many aspects of tumor biology. Dramatic improvements have been made in understanding the mechanisms of action of human carcinogens (i.e., virus, radiation, and chemical carcinogens), in elucidating the mechanisms underlying the development of human cancer, in understanding the ways in which chemotherapeutic agents work, and in identifying molecular mechanisms of drug resistances. Although studies on soft tissue sarcoma have in general lagged behind those on the more common malignancies, such as tumors of breast and colon, in the last few years several key advances have been made. First, there have been many reports of cytogenetic abnormalities and of alteration in dominant oncogenes and tumor suppressor genes on soft tissue. Secondly, it is well established that some inherited disorders can predispose to the development of soft tissue sarcomas, and for many of these the genes harboring the inherited mutation have now been cloned and characterized. Thirdly, the discovery of specific chromosomal translocations in some classes of soft tissue tumor and the identification of genes that control differentiation towards striated muscle have provided new markers that can be used in the diagnosis of soft tissue tumors. Finally, studies on tumor ploidy and the expression of genes that control drug resistance have identified a number of important new prognostic indicators. These recent developments are the subject of this review.