Soft tissue sarcoma is a rare type of cancer that starts as a growth of cells in the body's soft tissues. The soft tissues connect, support and surround other body structures. Soft tissues include muscle, fat, blood vessels, nerves, tendons and linings of the joints.
Soft tissue sarcoma can happen anywhere in the body. It happens most often in the arms, legs and belly.
More than 50 types of soft tissue sarcoma exist. Some types are more likely to affect children. Others affect mostly adults. These cancers can be hard to diagnose because they may be mistaken for many other types of growths.
Soft tissue sarcoma treatment usually involves surgery. Other treatments might include radiation therapy and chemotherapy. Treatment depends on the size, type and location of the cancer and how quickly it grows.
A soft tissue sarcoma may not cause any symptoms at first. As the cancer grows, it may cause:
- A noticeable lump or swelling.
- Pain, if the growth presses on nerves or muscles.
When to see a doctor
Make an appointment with your health care team if you have any symptoms that worry you.
It's not clear what causes most soft tissue sarcomas.
Soft tissue sarcoma starts when a connective tissue cell gets changes in its DNA. A cell's DNA holds the instructions that tell a cell what to do. The changes turn the connective tissue cells into cancer cells. The changes tell the cancer cells to grow and make more cells. Healthy cells die as part of their natural cycle, but cancer cells keep growing because they do not have instructions to stop.
The cancer cells form a growth, called a tumor. In some types of soft tissue sarcoma, the cancer cells stay in one location. They continue making more cells and cause the tumor to get bigger. In other types of soft tissue sarcoma, the cancer cells might break away and spread to other parts of the body.
The type of cell with DNA changes is what determines the type of soft tissue sarcoma. For example, angiosarcoma begins in cells in the lining of blood vessels, while liposarcoma starts in fat cells.
Some types of soft tissue sarcoma include:
- Dermatofibrosarcoma protuberans.
- Epithelioid sarcoma.
- Gastrointestinal stromal tumor (GIST).
- Kaposi's sarcoma.
- Malignant peripheral nerve sheath tumor.
- Solitary fibrous tumor.
- Synovial sarcoma.
- Undifferentiated pleomorphic sarcoma.
Factors that may raise the risk of sarcoma include:
- Inherited syndromes. A risk of soft tissue sarcoma can run in families. Genetic syndromes that increase the risk include hereditary retinoblastoma, Li-Fraumeni syndrome, familial adenomatous polyposis, neurofibromatosis, tuberous sclerosis and Werner syndrome.
- Chemical exposure. Being exposed to certain chemicals may increase the risk of soft tissue sarcomas. These chemicals include herbicides, arsenic and dioxin.
- Radiation exposure. Radiation therapy for other cancers can increase the risk of soft tissue sarcomas.
Tests and procedures used to diagnose soft tissue sarcoma include imaging tests and procedures to remove a sample of cells for testing.
Imaging tests create pictures of the inside of the body. They might help show the size and location of the soft tissue sarcoma. Examples include:
- CT scans.
- MRI scans.
- Positron emission tomography (PET) scans.
Removing a sample of tissue for testing
A procedure to remove some cells for testing is called a biopsy. A biopsy for soft tissue sarcoma needs to be done in a way that won't cause problems with future surgery. For this reason, it's a good idea to seek care at a medical center that sees many people with this type of cancer. Experienced health care teams will select the best type of biopsy.
Types of biopsy procedures for soft tissue sarcoma include:
- Core needle biopsy. This method uses a needle to remove tissue samples from the cancer. Doctors usually try to take samples from several parts of the cancer.
- Surgical biopsy. In some cases, your doctor might suggest surgery to get a larger sample of tissue.
The biopsy sample goes to a lab for testing. Doctors who specialize in analyzing blood and body tissue, called pathologists, will test the cells to see if they're cancerous. Other tests in the lab show more details about the cancer cells, such as what type of cells they are.
Treatment options for soft tissue sarcoma will depend on the size, type and location of the cancer.
Surgery is a common treatment for soft tissue sarcoma. During surgery, the surgeon usually removes the cancer and some healthy tissue around it.
Soft tissue sarcoma often affects the arms and legs. In the past, surgery to remove an arm or leg was common. Today, other approaches are used, when possible. For example, radiation and chemotherapy might be used to shrink the cancer. That way the cancer can be removed without needing to remove the entire limb.
Radiation therapy uses powerful energy beams to kill cancer cells. The energy can come from X-rays, protons and other sources. During radiation therapy, you lie on a table while a machine moves around you. The machine directs radiation to specific points on your body.
Radiation therapy might be used:
- Before surgery. Radiation before surgery can shrink a tumor to make it easier to remove.
- During surgery. Radiation during surgery allows more radiation to be delivered directly to the target area. This can spare healthy tissues around the target area.
- After surgery. Radiation may be used after surgery to kill any cancer cells that remain.
Chemotherapy uses strong medicines to kill cancer cells. The medicines are often given through a vein, though some are available in pill form. Some types of soft tissue sarcoma respond better to chemotherapy than do others. For instance, chemotherapy is often used to treat rhabdomyosarcoma.
Targeted therapy uses medicines that attack specific chemicals in the cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die. Your cancer cells might be tested to see if targeted therapy might be helpful for you. This treatment works well for some types of soft tissue sarcoma, such as gastrointestinal stromal tumors, also called GISTs.
Coping and support
A diagnosis of cancer can feel overwhelming. With time you'll find ways to cope with the distress and uncertainty of cancer. Until then, you may find it helps to:
- Learn enough about sarcoma to make decisions about your care. Ask your health care team about your soft tissue sarcoma. Discuss your treatment options. If you want to, ask about your prognosis. As you learn more, you may become more confident in making treatment decisions.
- Keep friends and family close. Keeping your close relationships strong will help you deal with soft tissue sarcoma. Friends and family can provide support, including taking care of your home if you're in the hospital. They can give emotional support when you feel overwhelmed by cancer.
- Find someone to talk with. Find a good listener who is willing to listen to you talk about your hopes and fears. This may be a friend or family member. Meeting with a counselor, medical social worker, clergy member or cancer support group also may be helpful.
Preparing for an appointment
Make an appointment with your usual doctor or other health care professional if you have any symptoms that worry you. If your doctor thinks you might have soft tissue sarcoma, you'll likely be referred to a cancer doctor, called an oncologist. Soft tissue sarcoma is rare and is best treated by someone who has experience with it. Doctors with this kind of experience are often found within an academic or specialized cancer center.
What you can do
- Write down any symptoms you have. This includes any symptoms that may seem separate from the reason for which you scheduled the appointment.
- Make a list of all medicines, vitamins or supplements that you're taking.
- Ask a family member or friend to come with you. Sometimes it can be hard to remember all the information given to you during an appointment. Someone who comes with you may remember something that you missed or forgot.
- Write down questions to ask your doctor.
Preparing a list of questions can help you make the most of your appointment time. List your questions from most important to least important in case time runs out. For soft tissue sarcoma, some basic questions to ask include:
- Do I have cancer?
- Are there other possible causes for my symptoms?
- What kinds of tests do I need to confirm the diagnosis? Do these tests require any special preparation?
- What type of sarcoma do I have?
- What stage is it?
- What treatments are available, and which do you recommend?
- Can the cancer be removed?
- What types of side effects can I expect from treatment?
- Are there clinical trials available?
- I have other health conditions. How can I best manage these conditions together?
- What's my prognosis?
- Are there any brochures or other printed material that I can take with me? What websites do you recommend?
- Are there other specialists that I should meet with for my cancer?
What to expect from your doctor
Be prepared to answer some basic questions about your symptoms and your health. Questions might include:
- When did you first notice your symptoms?
- Are you experiencing pain?
- Does anything seem to improve your symptoms?
- What, if anything, appears to worsen your symptoms?
- Do you have any family history of cancer? If so, do you know what type of cancer?