Genetic Fingerprinting Improves Diagnosis And Treatment Of Sarcoma

Because these drugs target tumors based on their unique genetic characteristics, the ability to accurately identify a cancer's biological makeup is key.

New research being presented at the 38th Annual Meeting of the American Society of Clinical Oncology demonstrates that a new technique enables doctors to distinguish the molecular differences among many subtypes of adult soft-tissue sarcoma, a type of cancer that is often difficult to diagnose and treat.

Using a sophisticated technology called oligonucleotide array analysis, researchers developed a genetic fingerprint of each sarcoma, which will ultimately improve the diagnosis of this varied group of tumors and aid the development of targeted therapies for this disease.

"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, MD, a medical oncologist at Memorial Sloan-Kettering Cancer Center and lead investigator of the study.

Soft-tissue sarcomas originate in tissues such as fat, muscles, nerves, tendons, and blood vessels.

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. Treatment usually involves surgery to remove the tumor followed by radiation therapy, and sometimes chemotherapy.

Many sarcomas look almost identical under the microscope, making it difficult to distinguish between certain subtypes and presenting unique challenges in detection and treatment.

For years, many pathologists grouped ambiguous sarcomas into a general category called malignant fibrous histiocytomas (MFH), a diagnosis that has been questioned as a distinct subtype of sarcoma. With current treatments, only about 50 percent of patients with MFH sarcoma survive the disease long-term. Now, researchers have been able to prove that MFH is in fact a separate subtype of the disease with unique genetic characteristics.

In the study, researchers tested 52 different samples of soft-tissue sarcoma on a single slide and analyzed the pattern of activity 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 MFH sarcomas, and discovered that some of them formed a distinct subtype.

Researchers identified genes characteristic of each kind of soft-tissue sarcoma, which may ulti