Epidemiology of bone and soft tissue sarcomas.

Although bone and soft tissue sarcomas are not common, a significant number of patients who develop these tumors will die with metastatic disease. Part of the reason is that many of the patients have advanced disease at diagnosis. Identification of an etiologic agent should allow for diagnosis at an earlier stage. This is particularly true of radiation-induced sarcomas because patients who develop this malignancy seem to have a poor prognosis. As more patients survive their malignancies, we may see an increase in the incidence of postradiation sarcomas. Therefore, patients who receive radiation should be monitored closely, and a high index of suspicion should be maintained for complaints referable to the irradiated site. The role of various chemical agents in the development of sarcomas needs further definition, as the literature is replete with conflicting reports. Problems exist in that we are dealing with a variety of agents with different levels of exposure, possibly resulting in different types of neoplasms. Additionally, many of the agents in question are not pure substances, but frequently are contaminated with other potentially carcinogenic agents. Finally, the majority of studies reported are from different countries. Thus, there may be unidentified operative genetic and environmental factors. The recent advances in cytogenetics and molecular biology have already resulted in a significant increase in information related to bone and soft tissue sarcomas. Many chromosomal abnormalities identified will have diagnostic, prognostic, and therapeutic implications. Even more exciting is the fact that the identification of chromosomal abnormalities directs us to investigate abnormal areas of the genome that may identify the changes responsible for malignant degeneration on a molecular basis.