What is synovial sarcoma?
Synovial sarcoma is a rare type of soft tissue sarcoma, or cancerous tumor.
About one to three people in a million receive a diagnosis of this disease each year. Anyone can get it, but it tends to strike during adolescence and young adulthood. It can begin in any part of your body, but usually starts in the legs or arms.
Continue reading to learn more about the symptoms and treatment options for this particularly aggressive form of cancer.
Synovial sarcoma doesn’t always cause symptoms in the early stages. As the primary tumor grows, you may have symptoms similar to those of arthritis or bursitis, such as:
- pain, especially if the tumor is pressing on a nerve
- limited range of motion in an arm or leg
You may also have a lump you can see and feel. If you have a mass in your neck, it may affect your breathing or change your voice. If it occurs in your lungs, it can lead to shortness of breath.
The thigh near the knee is the most common site of origin.
The exact cause of synovial sarcoma isn’t clear. But there is a genetic link. In fact, more than 90 percent of cases involve a particular genetic change in which parts of chromosome X and chromosome 18 switch places. What prompts this change is unknown.
This isn’t a germinal mutation, which is a mutation that can be passed from one generation to another. It’s a somatic mutation, which means that it’s not hereditary.
Some potential risk factors may include:
- having certain inherited conditions such as Li-Fraumeni syndrome or neurofibromatosis type 1
- exposure to radiation
- exposure to chemical carcinogens
You can get it any age, but it’s more common in teens and young adults.
Before settling in on a treatment plan, your doctor will consider a number of factors such as:
- your age
- your general health
- the size and location of the primary tumor
- whether or not the cancer has spread
Depending on your unique circumstances, treatment may involve a combination of surgery, radiation, and chemotherapy.
Most of the time, surgery is the primary treatment. The goal is to remove the entire tumor. Your surgeon will also remove some healthy tissue around the tumor (margins), lowering the chance of cancer cells being left behind. The size and location of the tumor can sometimes make it harder for the surgeon to get clear margins.
It may not be possible to remove the tumor if it involves nerves and blood vessels. In these cases, amputating the limb may be the only way to take out the whole tumor.
Radiation therapy is a targeted treatment that can be used to help shrink the tumor prior to surgery (neoadjuvant therapy). Or it can be used after surgery (adjuvant therapy) to target any cancer cells that remain.
Chemotherapy is a systemic treatment. Powerful drugs are used to destroy cancer cells wherever they may be. Chemotherapy may help stop cancer from spreading or slow disease progression. It may also help prevent recurrence. Chemotherapy can occur before or after surgery.
The overall survival rate for people with synovial sarcoma is 50 to 60 percent at five years and 40 to 50 percent at 10 years. Keep in mind that these are simply general statistics, and they don’t predict your individual outlook.
Your oncologist can give you a better idea what to expect based on factors unique to you, such as:
- stage of cancer at diagnosis
- lymph node involvement
- grade of tumor, which suggests how aggressive it is
- size and location of the tumor or tumors
- your age and general state of health
- how well you respond to therapy
- whether or not this is a recurrence
Generally speaking, the earlier a cancer is diagnosed and treated, the better the prognosis. For example, a person with a single small tumor that can be removed with clear margins may have an excellent prognosis.
Once you finish treatment, you’ll need periodic scans to check for recurrence.
Your doctor will begin by assessing your symptoms and performing a physical exam. Diagnostic testing will probably include complete blood count and blood chemistries.
Imaging tests can help provide a detailed look at the area in question. These may include:
- CT scan
- MRI scan
- bone scan
If you have a suspicious mass, the only way to confirm the presence of cancer is by having a biopsy: A sample of the tumor is removed with a needle or through a surgical incision. Then it’s sent to a pathologist for analysis under a microscope.
A genetic test called cytogenetics can confirm the rearrangement of chromosome X and chromosome 18, which is present in most cases of synovial sarcoma.
If cancer is found, the tumor will be graded. Synovial sarcoma is typically a high-grade tumor. This means that the cells bear little resemblance to normal, healthy cells. High-grade tumors tend to spread faster than low-grade tumors. It metastasizes to distant sites in about half of all cases.
All this information is used to help decide on the best course of treatment.
The cancer will also be staged to indicate how far it has spread.
Synovial sarcoma can spread to other parts of your body, even when it’s been dormant for some time. Until it grows to a substantial size, you may not have symptoms or notice a lump.
That’s why it’s so important to follow up with your doctor even after treatment has ended and you have no sign of cancer.
The most common site of metastasis is the lungs. It can also spread to lymph nodes, bone, and your brain and other organs.
Synovial sarcoma is an aggressive form of cancer. So it’s important to choose doctors who specialize in sarcoma and to continue working with your doctor after treatment has ended.