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Synovial Sarcoma is a rare type of cancer that affects the soft tissues around the joints in the body. It can typically appear in knees, shoulders, hips, and ankles. Despite its name, the cancer does not arise from the synovial tissue of the joints. Instead, it affects the soft tissues such as muscles, tendons, and ligaments around the joints.
What is synovial sarcoma?
Sarcomas is a kind of cancer that arises in bones, joints, muscles, fat in the limbs and spine. Synovial sarcoma is a rare type of cancer that accounts for less than 1% of all cancers, says Dr Rajeev Reddy, consultant orthopedic oncosurgeon, Apollo Cancer Center, Hyderabad. “Soft tissues are the ones that connect and hold the body together which include blood vessels, nerves, and muscles,” he said.
Synovial sarcoma affects young people between the age group of 20 – 40 years and is commonly seen in the knees and the shoulder, said Dr Reddy. “As the cancer causes no symptoms, it’s often diagnosed at a later stage when the person starts experiencing pain,” he said.
According to National Cancer Institute US, Synovial sarcoma accounts for 5% to 10% of soft-tissue tumors. For every one million people, one to two are diagnosed with synovial sarcoma per year in the US.
Symptoms of synovial sarcoma
Like any other cancer, synovial sarcoma too starts with a painless lump or swelling in the joints that grows and starts pressing the nerves, resulting in pain. “These swellings occur without any injury and are often neglected as they are painless. As the tumor grows, the pressure on the surrounding nerves or the joint starts to affect the person’s joint movement and mobility,” said Dr Reddy.
There are two stages of cancer in sarcomas. “In the first stage, the tumor is restricted to one particular limb, bone, or joint. It starts to spread to other parts of the body in the second stage. When people come to us, it’s difficult to say which stage they are in until we get a PET scan,” he explained, adding that initial diagnosis is done through an MRI or an X-ray and a biopsy.
In any sarcoma cancer, the tumor is known to spread by blood. “The cancer cells spread into the blood and settle down in the lungs due to increased blood flow. The tumor in the knee can easily spread to the lungs which is detected through a PET scan,” said Dr Reddy.
Risk factors of sarcoma
According to American Cancer Society, radiation exposure accounts for less than 5% of sarcomas. However, people might develop sarcomas from radiation given to treat other cancers, like breast cancer or lymphoma. The sarcoma often starts in the part of the body that was treated with radiation. The average time between the radiation treatments and the diagnosis of a sarcoma is about 10 years.
Family cancer syndromes are disorders caused by gene defects (mutations) that people are born with (often inherited from a parent) and are linked to a high risk of getting certain cancers. Some family cancer syndromes increase a person’s risk of developing soft tissue sarcomas.
Treatment
Dr Reddy says that sarcoma is based on a triangular principle, the three corners of the triangle being surgery, radiation, and chemotherapy. “Our primary goal is to make sure that we remove the entire sarcoma and at the same time we retain as much healthy muscle and healthy bone as possible. It’s not about just saving the person’s leg but also ensuring that they can walk and carry on all activities they did before,” he said, recalling that earlier, surgeons would opt for amputation to ensure the tumor was removed.
Radiation therapy is given post-surgery to ensure that the tumor doesn’t come back or cause any problems, he said. “Surgery and radiation are both used in synovial sarcoma. Chemotherapy is a must if the person is too young or if the cancer is present in the lungs. Depending on the tumour size, a pre-surgery chemotherapy is done to reduce or shrink the size,” he explained.
Takeaways
- Synovial Sarcoma is a rare type of cancer that affects the soft tissues around the joints.
- Cancer arises in knees, shoulders, hips, and ankles. It’s commonly seen in legs and arms, mostly in young adults.
- Synovial sarcoma starts with a painless lump or swelling in the joints that grows and starts pressing the nerves, resulting in pain.
- Sarcoma treatment is based on a triangular principle, the three corners of the triangle being surgery, radiation, and chemotherapy.
