Orlando, FL, May 19, 2002 - Decades of research into the cell's molecular mechanics have produced a promising arsenal of drugs that selectively attack cancer cells and leave the surrounding normal tissue relatively untouched.
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 ultimately lead to new, targeted drugs for patients with this 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," he said.
Memorial Sloan-Kettering experts have pioneered the molecular classification and diagnosis of many sarcoma subtypes and are leading the search for genetic markers that may help determine the aggressiveness of tumors and their potential response to treatment. In fact, Sloan-Kettering houses the largest dedicated database for soft-tissue sarcoma of any single institution anywhere.
As Dr. Maki notes, "The knowledge we have gained from this database has allowed us to help patients avoid excessive surgery, radiation therapy, and chemotherapy, and to anticipate how patients will respond to these therapies."
Researchers from Columbia University collaborated on the work, which was supported by the National Cancer Institute.
Memorial Sloan-Kettering Cancer Center is the world's oldest and largest institution devoted to prevention, patient care, research and education in cancer. Our scientists and clinicians generate innovative approaches to better understand, diagnose and treat cancer. Our specialists are leaders in biomedical research and in translating the latest research to advance the standard of cancer care worldwide.