Jonathan C. Trent, MD, PhD
Breelyn A. Wilky, MD
Sylvester Comprehensive Cancer Center
University of Miami Miller School of Medicine
Determining the best course of treatment for sarcomas of the bone and soft tissues is a complex process. Clinicians have identified more than 100 different types of sarcomas such as gastrointestinal stromal tumors (GISTs), as well as benign tumors such as desmoid fibromatosis, chordoma, giant cell tumors of bone, or pigmented villonodular synovitis. Because making an accurate diagnosis is essential to developing effective personalized treatment strategies, practice guidelines from the National Comprehensive Cancer Network call for patients with sarcoma to be evaluated at sarcoma centers with experienced, multidisciplinary teams.
The Bone and Soft Tissue Sarcoma Program at the Sylvester Comprehensive Cancer Center— South Florida’s only Cancer Center of Excellence— provides an example of how this patient management approach can be put into practice, leading to better outcomes. Each year, our team sees more than 600 new pediatric, adolescent, and adult cases, serving as a vital resource for patients from throughout the United States, the Caribbean, and Latin America.
The Patient’s Journey
Imaging and Biopsy
A typical patient journey begins with a phone call from a patient or referring physician to the sarcoma nurse navigator, who gathers information and organizes the process.
The first step involves appropriate imaging. A musculoskeletal radiologist may identify unique imaging features on CT or MRI scans that suggest sarcoma. Together, the radiologist and orthopedic oncologists determine the best approach for a biopsy.
An accurate biopsy is vital. A mistake in the biopsy approach can lead to contamination of surgical planes, necessitating a more extensive surgery or even higher risk for recurrent disease. Biopsy material and any archival tissue from outside institutions are then forwarded to our board-certified pathologist, Andrew E. Rosenberg, MD, chief of Anatomic Pathology, and director of the Bone and Soft Tissue Service. Dr Rosenberg has extensive experience in diagnosing musculoskeletal neoplasms and metabolic bone disease.
At this juncture, additional molecular or immunohistochemical analysis is employed to make every effort to subtype the sarcoma. At Sylvester, the diagnostic process includes molecular analysis of tumor tissue for mutations, translocations, amplifications, or deletions. These additional analyses can drastically alter treatment plans.
For example, Dr Rosenberg played a pivotal role in describing a gene mutation in the isocitrate dehydrogenases (IDH) enzyme and discovering that it expressed very frequently in chondrosarcoma.
With that finding, our researchers have been studying the mutation in chondrosarcoma cell lines in the lab and have partnered with industry to conduct the first clinical trials of IDH inhibitors. Now, all suspected chondrosarcomas are submitted for IDH testing up front so that patients with this mutation may be offered clinical trials of IDH inhibitors, if appropriate, for the current disease stage.
Another example occurs in patients with GIST, the most common sarcoma of the GI tract. All patients are tested for the KIT gene mutation at diagnosis. If the mutation is in the exon 11 region of that gene, we treat it with 400 mg of imatinib aday. If the mutation lies in the exon 9 region, we treat the patient with 800 mg a day.