Sarcoma

Sarcoma is a rare type of cancer that begins in the bones and soft tissues of the body. Although sarcomas make up only 1% of all adult cancers, they require specialized care from expert teams who understand how to treat these complex diseases.

Table of contents

• What Is Sarcoma
• Types of Sarcoma
• Where Sarcomas Are Found
• Who Is Affected by Sarcoma
• Signs and Symptoms
• Causes and Risk Factors
• How Sarcoma Is Diagnosed
• Treatment Options
• Survival Rates
• Living With and Beyond Sarcoma

What Is Sarcoma

Sarcoma refers to a broad group of cancers that start in the bones and soft tissues — the tissues that connect, support, and surround other body structures^[1]. These soft tissues include muscle, fat, blood vessels, nerves, tendons, cartilage (a flexible tissue that cushions bones), ligaments (tissues that connect bones to each other), and the tissue that surrounds bones and joints^[2].

When cancer starts in soft tissue, it is called soft tissue sarcoma. Cancer that starts in the bone is called bone sarcoma. Connective tissue is made up of cells and fibers that connect and support other parts of the body^[3]. Since you have connective tissue throughout your body, sarcomas can develop anywhere — from your head to your toes.

Sarcomas are rare. They make up only about 1% of all adult cancer diagnoses and about 15% of childhood cancer diagnoses^[2]. Approximately 16,000 sarcomas are diagnosed in the United States each year, including around 4,000 bone sarcomas and approximately 13,000 soft tissue sarcomas^[2].

Types of Sarcoma

Sarcoma refers to a large group of cancers in bone and soft tissue. There are more than 70 known subtypes of sarcoma, and more than 60 different types of soft tissue sarcomas^[2][4]. These cancers are classified based on the specific tissue and type of cell from which the tumor originates.

Bone sarcomas are cancers that start in the bone. More than one-third of bone sarcomas are diagnosed in people younger than 35 years old, and many are diagnosed in children^[2]. Common types of bone sarcoma include:

• Osteosarcoma (the most common type)
• Chondrosarcoma
• Chordoma
• Ewing’s sarcoma
• Fibrosarcoma

Soft tissue sarcomas begin in the muscle or other connective tissues of your body. Unlike bone sarcomas, most soft tissue sarcomas occur in adults. However, certain types of sarcoma, such as rhabdomyosarcoma, are found mostly in children^[2]. Common types of soft tissue sarcoma include:

• Angiosarcoma
• Desmoplastic small round cell tumors
• Gastrointestinal stromal tumor (GIST)
• Leiomyosarcoma
• Liposarcoma
• Malignant peripheral nerve sheath tumor
• Myxofibrosarcoma
• Rhabdomyosarcoma
• Synovial sarcoma
• Undifferentiated pleomorphic sarcoma

Where Sarcomas Are Found

Sarcomas can form in various parts of your body — anywhere from your head to your toes. Many sarcomas grow in the arms and legs^[3]. The distribution of where sarcomas occur in the body is as follows:

• 40% occur in the lower extremities (legs, ankles, feet)
• 15% occur in the upper extremities (shoulders, arms, wrists, hands)
• 30% occur in the trunk, chest wall, abdomen, or pelvis
• 15% occur in the head and neck^[2]

About 50% to 60% of soft tissue sarcomas occur in the arms and legs^[6].

Who Is Affected by Sarcoma

Sarcoma affects both children and adults. Generally, soft tissue sarcoma occurs more frequently in adults. Bone sarcoma diagnoses occur more often in children, teens, and people older than 65 years^[2]. About half of all sarcomas occur before age 40, which may be because sarcomas often form during growth spurts^[3].

Bone sarcoma occurs more frequently in males and people who are Black or Hispanic^[2]. Between 1,500 and 1,700 children are diagnosed with a bone or soft tissue sarcoma in the United States each year. This makes up about 15% of cancers in children under the age of 20^[6].

Approximately 229,000 Americans are living with sarcoma^[3].

Signs and Symptoms

In their early stages, soft tissue sarcomas rarely display any symptoms other than a painless lump^[6]. A sarcoma may appear as a painless lump under the skin, often on an arm or a leg^[9]. The main signs and symptoms of sarcoma include:

• A lump that can be felt through the skin that may or may not be painful
• Bone pain
• A bone that breaks with no clear cause, such as with a minor injury or no injury
• Belly pain
• Weight loss^[1]

Sarcomas that begin in the abdomen may not cause signs or symptoms until they get very big. As the sarcoma grows and presses on nearby organs, nerves, muscles, or blood vessels, additional signs and symptoms may include pain or trouble breathing^[9].

Other conditions may cause the same signs and symptoms. If you have symptoms that worry you, make an appointment with a doctor or other healthcare professional^[1].

Causes and Risk Factors

It’s not clear what causes sarcoma. This cancer starts as a growth of cells in the bones and soft tissues. Sarcoma happens when cells develop changes in their DNA — the instructions that tell the cell what to do^[1].

Sarcomas form when immature bone or soft tissue cells have changes to their DNA, and they develop into cancer cells that grow in an unregulated way. They may eventually form a mass or tumor that can invade nearby healthy tissues. Left untreated, the cancer can travel via your bloodstream or lymphatic system (the network of vessels and nodes that help fight infection) from the primary location where it formed to other organs. This spread is called metastasis, and metastasized cancer is challenging to treat^[2].

As with other forms of cancer, researchers don’t know what causes a healthy cell to become sarcoma. The majority of sarcoma cases occur spontaneously^[2][4]. However, certain factors may raise your risk of developing sarcoma:

Genetic conditions and family history: Families with rare cancer syndromes are more likely to get sarcomas^[3]. Several genetic conditions can increase risk, including:

• Neurofibromatosis Type 1 (NF1): An inherited condition caused by mutations in the NF1 gene, which results in multiple growths on nerves. This gene normally helps suppress tumor growth^[4]
• Li-Fraumeni Syndrome: A rare inherited disorder caused by mutations in the TP53 gene, which helps clear damaged cellular DNA. Some patients will develop rhabdomyosarcoma by the age of 4^[4]
• Familial Adenomatous Polyposis (FAP): A condition with mutations in the APC gene that can lead to desmoid tumors, typically arising about five years after surgery^[4]
• Other genetic conditions including Gardner syndrome, Retinoblastoma, Werner syndrome, Gorlin syndrome, and tuberous sclerosis^[6]

Radiation exposure: Exposure to high doses of radiation from previous cancer treatment can increase risk. Patients might develop sarcomas from radiation given to treat other cancers like breast cancer, cervical cancer, lymphoma, and retinoblastoma. The sarcoma often starts in the area of the body that had been treated with radiation, and on average, can take about 10 years to develop. Radiation exposure accounts for less than 5% of sarcomas^[2][6].

Chemical exposure: Exposure to certain chemicals may increase risk, including arsenic, chemicals used to make plastics (vinyl chloride monomer), herbicides (phenoxyacetic acid), wood preservatives (chlorophenols), and dioxin^[2][6].

Lymphedema: Long-term swelling in the arms or legs^[2].

How Sarcoma Is Diagnosed

Sarcoma diagnosis often begins with a physical exam. Your healthcare professional may ask about your symptoms and your health history. A physical exam can help your healthcare professional understand your symptoms and look for other clues that help with your diagnosis^[8].

Because sarcomas are so rare and can take multiple forms in multiple locations, they are difficult to detect and often misdiagnosed^[6]. The tests you have may depend on the part of your body that’s affected^[8].

Imaging tests make pictures of the inside of the body. The pictures can help your healthcare team understand the size of your sarcoma and where it is. The imaging tests you have depend on your condition. Some tests, such as X-rays, are better for seeing bones. Other tests, such as MRIs (magnetic resonance imaging scans), are better for seeing connective tissues. Other imaging tests may include ultrasound, CT scans (computed tomography scans), bone scans, and PET scans (positron emission tomography scans)^[8].

Biopsy: A biopsy is a procedure to remove a sample of tissue for testing in a lab. How a healthcare professional collects the biopsy sample depends on where the affected tissue is. A biopsy for sarcoma may involve placing a needle through the skin to get the sample, or it may involve surgery. Sometimes a surgeon does a biopsy during surgery to remove the cancer^[8].

With a rare and complex cancer such as sarcoma, it is important to seek the best possible care. Many doctors have never seen or treated a patient with sarcoma. It’s recommended to get a second opinion from a doctor that specializes in sarcoma about the initial diagnosis and the treatment plan, even if you are being treated at a major cancer center^[6].

Treatment Options

Treatment for sarcoma often involves surgery to remove the cancer. Other treatments for sarcoma may include radiation therapy, ablation therapy, and treatment with medicines. Medicines that help treat sarcoma include chemotherapy, targeted therapy, and immunotherapy^[8].

Which treatments are best depends on the sarcoma type, where it is located, and other factors^[1]. Your treatment plan will be specific to you and based on how quickly or slowly the type of cancer you have may spread, how far the cancer has spread, and your overall health. One or more treatments may be used^[2].

Surgery can remove the cancerous tumor, nearby tissue, and possibly nearby lymph nodes. In many cases, surgery to remove the tumor is a very important part of treatment^[11].

Radiation therapy (also called radiotherapy) kills cancer cells and shrinks tumors. Radiation after surgery significantly reduces the chances of the cancer coming back. It can include external radiation therapy — radiation directed at the tumor from a source outside the body — or internal radiation therapy, where radioactive materials are placed into the body near the cancer cells^[11].

Chemotherapy uses drugs to kill cancer cells. The drugs enter the bloodstream and travel through your body, killing mostly cancer cells but also some healthy cells. Only certain types of sarcomas get treated with chemotherapy. In some bone sarcomas, chemotherapy significantly and positively impacts the outlook for patients^[10][11].

Targeted therapy uses drugs that target specific features of cancer cells to stop their growth^[2].

Immunotherapy helps your immune system fight cancer. There are several FDA-approved immunotherapy options for patients with sarcoma, including checkpoint inhibitors that target specific pathways^[10].

It is essential to find the right fit for treatment. Start by identifying a high-volume sarcoma center — one that treats a minimum of 50 sarcoma patients yearly. Because sarcomas are rare, you need treatment by a care team that specializes in this disease^[16].

Survival Rates

Survival rates use a percentage known as the five-year relative survival rate. This statistic compares your chance of surviving five years after diagnosis compared to someone your age who doesn’t have cancer^[3].

The overall relative five-year survival rate for people with sarcoma is around 50%^[6]. Survival rates depend on the type of sarcoma. They are higher when sarcoma starts in an arm or leg, and when the cancer is caught before it spreads^[3].

Soft tissue sarcoma: The survival rate is 83% if sarcoma is found before it spreads, according to data from the American Cancer Society. Ten-year survival rates are similar, which suggests that those who survive five years are likely to be cured^[3].

Sarcomas are easier to treat if you catch them early, before they spread^[3]. When the sarcoma starts in an arm or leg, the five-year survival rates are slightly higher for each stage when compared with sarcoma that starts in other locations^[6].

Living With and Beyond Sarcoma

After treatment for sarcoma, you will have regular follow-up appointments for several years. Follow-up care is a key part of your treatment and safety^[19][20]. Your follow-up appointments should include:

• A chance to discuss symptoms
• An examination to look for any signs of the sarcoma returning
• A chest X-ray to rule out any secondary cancers in the lungs^[19]

It is a good idea to check for cancer coming back yourself. Your doctor or sarcoma clinical nurse specialist can tell you what signs to look out for. This can be a frightening and stressful time, so it’s important to get support^[19].

Managing physical effects: If you have had major surgery, you will have trouble moving the affected limb to start with. Physiotherapists will give you exercises that will gradually make moving easier. Anyone diagnosed with a bone or soft tissue sarcoma can benefit from specialist advice and treatment to speed recovery and help deal with the effects of sarcoma and treatment^[15][19].

Emotional support: The physical and emotional changes you experience might affect your relationships. All sorts of feelings are likely to come and go, and these are a natural part of coming to terms with cancer. Sometimes it’s hard to take in the fact that you have cancer at all. You may feel shocked, upset, numb, frightened, uncertain, confused, angry, or guilty^[15]. There is help and support available if you need it, including counseling services^[2].

Practical tips for coping:

• Eat healthy food. Focus on foods with enough protein and calories to help you keep up your strength
• Get some physical activity every day, but do not get too tired
• Get enough sleep, and take time to do things you enjoy
• Think about joining a support group or discuss your concerns with a doctor or counselor^[20]

You may be more able to cope and make decisions if you have information about your type of cancer and its treatment. Make a list of questions before you see your doctor. Take someone with you to remind you what you want to ask. They can also help you to remember the information that was given^[15].

If you have not already done so, consider preparing an advance care plan. An advance care plan provides instructions to your doctor and family members about what kind of care you want if you become unable to speak or express yourself^[20].