Sarcomas get much less attention than major cancer types. Rebecca D. Dodd and colleagues at Duke University, North Carolina, reported that survival from the most common subtypes of soft tissue sarcomas has not improved for several decades. Research is challenging, she explained, because there are over 75 subtypes, and each one is relatively rare. Sarcomas can occur almost anywhere in the body. They arise from mesenchymal tissue in the fat, muscle, cartilage, fibrous tissue, blood vessels, or bones. Bone sarcomas are considered a separate group from soft tissue sarcomas.
For children, soft tissue sarcomas account for about 15 percent of total cancer diagnoses. Adults have a different cancer profile, with less than 1 percent of all malignancies in this class. Dodd reported that animal models have been developed over the past 10 years, so that researchers have a better chance to develop new treatments.
Dr. Keith M. Skubitz and Dr. David R. D'Adamo of the University of Minnesota and Memorial Sloan Kettering Cancer Center, New York, provided a review of sarcomas. The major types of soft tissue sarcomas are:
1. Kaposi's sarcoma. This is the one most of us have heard about, because it is typically the first illness that AIDS patients suffer. The human herpesvirus 8 appears to be the cause. It is rare in individuals with a healthy immune system, but organ transplant recipients as well as AIDS patients are susceptible.
2. Liposarcoma. The most common subtype in adults. Well-differentiated tumors are unlikely to metastasize, and can be treated by surgery alone.
3. Rhabdomyosarcoma. The most common solid tumor in children. Cure rates have progressed from 20 percent to over 70 percent in the last few decades. It is rare in adults.
4. Leiomyosarcoma. This subtype may occur anywhere in the body, but tumors that originate in the uterus may involve different genetic expression.
5. Synovial sarcoma. The name implies that it would occur in the joints, but this is not the case. The name comes from the appearance of the cancerous cells when examined under the microscope; they resemble synovial cells.
6. Angiosarcoma. This subtype occurs mostly on the scalp or face.
7. Gastrointestinal stromal tumors (GIST). Approximately 50 percent occur in the stomach and 25 percent in the small intestine.
Skubitz and D'Adamo recommended evaluation and treatment by doctors who have experience specifically with sarcomas, since they are rare enough that some oncologists may not be familiar with them.
References:
1. Dodd RD et al, “Animal models of soft-tissue sarcoma”, Disease Models & Mechanisms 2010; 3: 557-66. http://www.ncbi.nlm.nih.gov/pubmed/20713645
2. Skubitz KM et al., “Sarcoma”, May Clinic Proceedings 2007 November; 82(11): 1409-1432. http://www.ncbi.nlm.nih.gov/pubmed/17976362
Reviewed June 29, 2011
Edited by Alison Stanton
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.