Soft Tissue Sarcoma

Soft tissue sarcoma is a rare type of cancer that starts in the body’s connective tissues, including muscles, fat, blood vessels, and nerves. Though these cancers can develop anywhere in the body, they most commonly appear in the arms, legs, and abdomen.

Table of contents

• What is soft tissue sarcoma?
• Types of soft tissue sarcoma
• Symptoms
• Causes and risk factors
• How soft tissue sarcoma is diagnosed
• Treatment options
• Living with soft tissue sarcoma

What is soft tissue sarcoma?

Soft tissue sarcoma is a rare type of cancer that begins as a growth of cells in the body’s soft tissues^[1]. The soft tissues are the parts of the body that connect, support, and surround other body structures. These include muscle, fat, blood vessels, nerves, tendons, and the linings of the joints^[1][5].

These cancers make up less than 1% of all adult solid tumors, which means they are quite uncommon^[7][12]. Because they are so rare, soft tissue sarcomas often cause a delay in diagnosis^[7].

Soft tissue sarcoma can happen anywhere in the body. It happens most often in the arms, legs, and belly^[1]. More than half of these cancers develop in an arm or leg. Others usually develop in the abdomen, chest, or head and neck area^[2][5].

Types of soft tissue sarcoma

There are more than 50 different types of soft tissue sarcoma^[1]. In fact, some sources indicate there are over 70 types^[2][5]. The type of sarcoma depends on what cell the cancer started in. Each type is named based on the type of soft tissue where the cancer began^[4][5].

Some of the more common types include:

• Liposarcoma: This tumor can develop in fat tissue, often in the legs or the back of the belly^[2][5].
• Leiomyosarcoma: This disease affects smooth muscle and often develops in the belly^[2][5].
• Myxofibrosarcoma: This soft tissue tumor may develop in fat or cartilage right under the skin^[2].
• Angiosarcoma: This disease forms in the inner lining of blood vessels and lymphatic vessels. It is a very aggressive type of soft tissue sarcoma^[2].
• Undifferentiated pleomorphic sarcoma: This is the most common type of soft tissue sarcoma. It typically forms in the arms and legs^[2].
• Gastrointestinal stromal tumors (GISTs): This type of soft tissue tumor develops in the digestive system^[2].
• Rhabdomyosarcoma: These tumors affect muscles in the arms, legs, head, neck, and belly. Children and teenagers are more likely to have this cancer than adults^[2].
• Synovial sarcoma: This type of tumor may form in the joints, belly, arms, legs, or lungs^[2].
• Malignant peripheral nerve sheath tumor: These are tumors that form in layers of tissue protecting the nerves in the peripheral nervous system^[2].

• Muscle
• Fat
• Blood vessels
• Nerves
• Tendons
• Ligaments
• Lymphatic vessels
• Fibrous tissue
• Cartilage
• Joints

Symptoms

Most soft tissue sarcomas grow very slowly. You can have one for months or years before you have symptoms^[2]. Soft tissue sarcoma may not cause any symptoms at first. As the cancer grows, it may cause problems^[1].

The most common symptom is a noticeable lump or swelling. A soft tissue sarcoma may appear as a painless lump under the skin, often on an arm or a leg^[1][9]. Sometimes there are no signs or symptoms until the tumor is big and presses on nearby nerves or other parts of the body^[3].

As the growth presses on nerves or muscles, you may experience pain^[1]. Sarcomas that begin in the abdomen may not cause signs or symptoms until they get very big^[9].

You should contact a healthcare provider if you have:

• A new lump or a fast-growing lump anywhere on your body^[2]
• A lump that starts to hurt^[2]
• Belly pain that gets worse^[2]
• Blood in your stool or stool that appears black^[2]
• Nausea and vomiting^[2]
• Unexplained weight loss^[2]
• Trouble breathing (if the tumor affects breathing)^[9]

Causes and risk factors

Experts don’t know the exact cause of soft tissue sarcoma^[2]. Genetic mutations cause some soft tissue sarcomas^[2]. Anything that increases a person’s chance of getting a disease is called a risk factor. Not every person with one or more of these risk factors will develop soft tissue sarcoma, and it will develop in people who don’t have any known risk factors^[9].

Some inherited disorders can increase your risk of developing soft tissue sarcoma, including:

• Li-Fraumeni syndrome (caused by a TP53 gene mutation)^[9]
• Neurofibromatosis type 1, also called von Recklinghausen disease (caused by an NF1 gene mutation)^[2][9]
• Gardner syndrome (caused by an APC gene mutation)^[9]
• Hereditary retinoblastoma^[2]
• Lynch syndrome^[2]
• Maffucci syndrome^[2]
• Tuberous sclerosis (also known as Bourneville disease)^[9]
• Werner syndrome (adult progeria)^[9]

Other risk factors include:

• Receiving radiation therapy in the past to treat other cancers^[2][9]
• Experiencing lymphedema (long-lasting swelling) in the arms or legs for a long time^[2][9]
• Having exposure to certain chemicals, such as thorium dioxide (Thorotrast), vinyl chloride, or arsenic^[2][9]
• Being infected with HIV and human herpesvirus 8, which have been linked to Kaposi sarcoma^[9]

How soft tissue sarcoma is diagnosed

A healthcare provider will ask about your symptoms and examine any unusual lumps or bumps that they can see and feel. They’ll do a physical exam to look for other symptoms^[2].

Several imaging tests may be used to create pictures of the inside of the body. These help show the size and location of the soft tissue sarcoma^[10]. These tests include:

• X-rays^[2][10]
• CT scans (computed tomography scans)^[2][10]
• MRI scans (magnetic resonance imaging)^[2][10]
• PET scans (positron emission tomography scans)^[2][10]

A procedure to remove some cells for testing is called a biopsy. A biopsy is needed to confirm the diagnosis of soft tissue sarcoma^[10]. It 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^[10].

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^[10].
• Surgical biopsy: In some cases, your doctor might suggest surgery to get a larger sample of tissue^[10].

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^[10].

Treatment options

Treatment options for soft tissue sarcoma depend on the size, type, and location of the cancer and how quickly it grows^[1]. A team of doctors and other professionals will work together to create a treatment plan that is best for you^[4].

Surgery

Surgery is the main treatment for soft tissue sarcoma^[1][7][17]. The aim is to remove as much of the cancer as possible^[17].

If you have sarcoma in one of your arms or legs, the surgeon will try to remove the cancer without damaging or removing your arm or leg. This is known as limb-sparing surgery^[7][17]. Advances in limb-sparing surgery have helped improve the quality of life in sarcoma patients drastically^[7].

Rarely, the surgeon may recommend removing your arm or leg, which is called amputation. This is usually only done if the sarcoma has come back after limb-sparing surgery^[17]. Historically, the standard for local control of these tumors was amputation, but advances in treatment have seen a shift toward preservation of the limb^[7].

If the cancer has spread, you may be offered further surgery^[17]. Surgical resection of local recurrence and lung metastases should be considered in individual patients^[13].

Radiation therapy

Radiation therapy uses high-energy rays of radiation to kill cancer cells^[17]. You may be offered radiation therapy to shrink the cancer before surgery, after surgery to help reduce the risk of the cancer coming back, or to help shrink cancers that have spread to other parts of the body^[17]. Surgical excision followed by post-operative radiotherapy is the standard management of high-grade limb sarcomas^[13].

Chemotherapy

Chemotherapy is not usually used to treat soft tissue sarcoma^[17]. However, you may be offered chemotherapy to shrink the cancer before surgery, if you have certain types of sarcoma that respond well to chemotherapy, or to slow the growth of the cancer and relieve your symptoms if it has spread^[17].

The standard first-line treatment for advanced disease involves anthracycline-based regimens, particularly the drug doxorubicin, which is used across nearly all subtypes^[12]. Single-agent doxorubicin is the standard first-line therapy for metastatic disease^[13].

Upon disease progression, second-line treatments such as gemcitabine, dacarbazine, ifosfamide, eribulin, and pazopanib are selected based on tumor type^[12].

Targeted medicines

Targeted medicines kill cancer cells. They are sometimes used to slow the growth of certain types of soft tissue sarcomas and help you live longer^[17]. Recent strides in research are starting to show promise, with advanced molecular profiling allowing researchers to tailor treatments to the unique genetic makeup of tumors^[12].

Treatment when cancer cannot be cured

If you’ve been diagnosed with advanced soft tissue sarcoma, it might be hard to treat and not possible to cure. The aim of your treatment will be to slow down the growth and spread of the cancer and its symptoms, and help you live longer^[17].

You will be referred to a special team of doctors and nurses called the palliative care team or symptom control team. They will work with you to help manage your symptoms and make you feel more comfortable^[17].

Living with soft tissue sarcoma

Follow-up care

When treatment ends, your doctors will still want to watch you closely. It’s very important to go to all of your follow-up appointments^[19]. During these visits, your doctors will ask questions about any problems you have and might do exams and lab tests or x-rays and scans to look for signs of cancer or treatment side effects^[19].

At first, these visits may be every 3 to 6 months. After 2 to 3 years, you may go to an every 6-month schedule for another few years. You can expect at least yearly check-ups for a long time after that^[19]. During this time, it’s very important to report any new symptoms to the doctor right away so that any problems can be found early when they’re easier to treat^[19].

Physical challenges

Limb-sparing surgery can be a very big operation involving cutting into a lot of tissue, bone, and muscle. It may leave you with a long scar^[18]. You might have some tightness and discomfort if you have radiotherapy to the area, as this can make healthy tissues less stretchy over time^[18].

You will have trouble moving the affected limb to start with. But your physiotherapists will give you lots of exercises that will gradually make moving easier for you^[18]. Rehabilitation can be an important part of healing after treatment, especially for soft tissue sarcoma of an arm or a leg^[20].

Some people feel pain or changes in sensation in the limb that has been amputated. This is called phantom limb pain^[20]. It happens because nerves are cut and damaged during surgery, which may cause the body to send abnormal nerve impulses^[20]. Phantom limb pain usually happens 1 to 4 weeks after surgery and usually lessens during the first year^[20].

Emotional and social challenges

How you look is an important part of your self-esteem. It can be very hard to accept sudden changes in your looks that you are not happy with^[18]. You may feel worried about how your friends and family see you. You may feel that you are no longer as physically attractive^[18].

Soft tissue sarcoma and its treatments can affect a person’s self-esteem and body image^[20]. Often this is because cancer or cancer treatments may result in body changes, such as scars and skin changes, hair loss, changes in how your body moves and works, or loss of a limb^[20].

The important thing to remember is that the people closest to you will not see you any differently as a person. Try and talk to them, they can help to support you when they know how you feel^[18].

Changes to your appearance might affect how you feel about sex. The physical and emotional changes you have might affect your relationships and sex life^[18]. There is help and support available if you need it. Your doctor could arrange counselling for you^[18].

Keeping health insurance and medical records

Even after treatment, it’s very important to keep health insurance. Tests and doctor visits cost a lot, and even though no one wants to think of their cancer coming back, this could happen^[19].

At some point after your cancer treatment, you might see a new doctor who doesn’t know your medical history. It’s important to keep copies of your medical records to be able to give your new doctor the details of your diagnosis and treatment^[19].

Adopting healthy behaviors

If you have (or have had) a soft tissue sarcoma, you probably want to know if there are things you can do that might lower your risk of the cancer growing or coming back, such as exercising or eating a certain type of diet. Unfortunately, it’s not yet clear if there are things you can do that will help^[21].

Adopting healthy behaviors such as not smoking, eating well, getting regular physical activity, and staying at a healthy weight might help, but no one knows for sure. However, we do know that these types of changes can have positive effects on your health^[21].