JULY IS SARCOMA AWARENESS MONTH
By TRA Radiologist
Michael Chester, MD
WHAT IS SARCOMA?
Sarcoma is a rare, malignant tumor that arises from a variety of soft tissues such as bone, fat, muscles, blood vessels, nerves, and joints. They can occur anywhere in the body but are most common in the arms or legs (60%) and torso/abdomen (30%). Bone and soft tissue sarcomas are the predominant types of sarcoma.
Sarcomas arise in both children and adults and account for approximately 1% of all adult cancers and 15% of all childhood cancers. There are approximately 17,000 new cases of sarcoma diagnosed in the United States each year.
- The first sign of sarcoma is usually a palpable lump underneath the skin.
- In some cases, the lump hurts when touched or causes pain with movement.
- Ewing sarcoma may cause unexplained fever or weight loss.
- Weakened bones may fracture.
- Not all lumps are cancer. However, a lump that increases in size or becomes painful warrants a visit to the doctor.
The cause of most sarcomas is unknown. There are a few risk factors which include: radiation exposure to treat other cancers, family cancer syndromes, and exposure to certain chemicals such as herbicides.
If a concerning lump is found by a patient or doctor then imaging should be obtained for further evaluation. If imaging is consistent with a soft tissue or bone tumor the next step is a biopsy to determine if the tumor is benign or malignant.
Imaging plays an important role in the diagnosis and pre and post operative management of patients with soft tissue sarcomas. No single imaging modality is ideal for every tumor. Therefore, a multimodality approach is necessary. Often, radiographs are initially obtained and are very helpful in diagnosing and characterizing bone tumors. Radiographs, while less helpful for soft tissue tumors, can still reveal certain patterns of soft tissue calcification that can be characteristic for certain tumors, such as hemangiomas.
CT, US, MRI, and PET-CT can all be used for diagnosis and staging of a sarcoma. MRI is usually the next imaging exam obtained after radiographs because it provides information about both bones and soft tissue. It can help characterize the tumor, stage the tumor locally, and provide the surgeon an idea of the tumor’s relationship to important surrounding structures such as nerves and arteries prior to resection. In addition, MRI is also used after resection and treatment to evaluate for tumor recurrence.
PET-CT and/or contrast enhanced CT are the modalities used to evaluate for metastases in other parts of the body. In some cases, bone scan will also be obtained to look for additional bone lesions.
In addition, CT and US are important to tools to assist in image-guided biopsies for the initial diagnosis of sarcoma.
Treatment of sarcomas typically depends on the stage of the cancer. Staging is based off of the pathology, size and grade of tumor, and whether the cancer has spread (metastasized) to lymph nodes or other parts of the body.
Surgery is the most common treatment for sarcomas. As much of the tumor is removed as possible. Radiation therapy may be used either before or after surgery to help shrink the tumor or kill tumor cells that could not be removed at surgery. Chemotherapy may be used with radiation therapy to shrink the tumor and to shrink tumors or reduce pain if the tumor has spread to other parts of the body.
Sarcoma is a rare cancer that has been called the “forgotten cancer.” Sarcoma awareness month presents an opportunity for the public to better understand the disease and encourage research and drug development. Patients and families often face immense challenges over the course of treatment of sarcoma. You can help by raising awareness on social media platforms and by donating at curesarcoma.org.
B.J. Manaster. Soft-tissue masses: optimal imaging protocol and reporting. American Journal of Roentgenology. 2013;201:505-514.