| Genetic
fingerprinting of tumors will improve diagnosis and treatment of adult
soft-tissue sarcomas A new molecular technique that creates genetic fingerprints of adult soft-tissue sarcomas will ultimately improve the diagnosis of this varied group of tumors and aid development of targeted treatments, according to research presented at the annual meeting of the American Society of Clinical Oncology. Investigators at Memorial Sloan-Kettering Cancer Center developed the oligonucleotide array analysis technique. "Our findings suggest that genetic fingerprinting of adult sarcomas will be useful in cases where pathologists disagree about a diagnosis or when the appearance of tumor cells does not conclusively link them to a particular subtype," said Robert Maki, M.D., lead investigator of the study. According to the American Cancer Society, approximately 8,700 new cases of soft-tissue sarcoma are diagnosed each year in adults and children in the United States. Many sarcomas look almost identical under the microscope, making it difficult to distinguish between certain subtypes that might have significantly different treatments. For years, many pathologists grouped ambiguous sarcomas into a general category called malignant fibrous histiocytomas, a diagnosis that has been questioned as a distinct subtype. With current treatments, only about 50 percent of these patients achieve long-term survival. With current findings in hand, it is now clear that malignant fibrous histiocytoma is in fact a separate subtype with unique genetic characteristics. In the study, researchers tested 52 different samples of soft-tissue sarcoma on a single slide and analyzed the expression pattern of approximately 12,500 genes. The technique allowed them to easily distinguish among soft-tissue sarcomas that have known genetic abnormalities. In addition, they were able to differentiate between certain malignant fibrous histiocytoma sarcomas, and they discovered that some formed a distinct subtype. Researchers identified gene expression patterns characteristic of each kind of soft-tissue sarcoma, which may ultimately lead to new, targeted drugs for patients with different subtypes of disease. "Genetic fingerprinting technology will
also enhance our ability to predict patient outcome," said
the study's senior author, Carlos Cordon-Cardo, MD, PhD, Director
of the Division of Pathology at Memorial Sloan-Kettering. "Because
we can see which genes are turned on or off in response to therapy,
the technology will help us determine whether a particular sarcoma
subtype will eventually become resistant to a given treatment."
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