Sarcoma: Full guide

What is sarcoma?

Sarcoma is a cancer that starts in the body's connective tissues. These include fat, muscle, blood vessels, nerves, deep skin tissue, cartilage, and bone. Sarcomas can start almost anywhere in the body.

There are two main groups. Soft tissue sarcomas start in soft tissues like fat or muscle. Bone sarcomas start in bone. GIST (gastrointestinal stromal tumor) is a type that starts in the wall of the stomach or bowel.

Sarcomas are rare. There are more than 100 kinds, and each can act differently. Most have no clear cause. Past radiation, some inherited gene changes, and some chemicals can raise the risk.

Because sarcoma is rare, it is best to be seen at a sarcoma center before any biopsy or surgery. An expert team can plan treatment that gives the best results, often while saving an arm or leg. Your care team will explain what your type means for you.

Types

Soft tissue sarcoma

The largest group. It often shows up as a painless lump that grows. It is most common in the arm, leg, belly, or the back of the belly (retroperitoneum). Common kinds include liposarcoma, leiomyosarcoma, and undifferentiated pleomorphic sarcoma.

Liposarcoma

A sarcoma that starts in fat cells. Some kinds grow slowly and others grow faster. It often grows in the thigh or the back of the belly.

Leiomyosarcoma

A sarcoma that starts in smooth muscle, the kind found in blood vessels, the uterus, and the gut. It can start in many places in the body.

Synovial sarcoma

Often found in the arms or legs of younger adults. It tends to respond better to chemotherapy than many other sarcomas.

GIST

Gastrointestinal stromal tumor. It starts in the wall of the stomach or small bowel. Most are driven by a gene change in KIT or PDGFRA, and targeted pills work very well. Chemotherapy does not work for GIST.

Osteosarcoma

The most common bone cancer. It is most common in teens and young adults, often near the knee. It is treated with chemotherapy and surgery.

Ewing sarcoma

A bone or soft tissue cancer most common in children, teens, and young adults. It is treated with chemotherapy plus surgery, radiation, or both.

Chondrosarcoma

A cancer of cartilage, most common in older adults. It often grows in the pelvis, hip, or shoulder. Surgery is the main treatment, because chemotherapy and radiation usually do not work well for the common type.

Desmoid tumor

A tumor of connective tissue that can grow into nearby tissue but does not spread to other organs. Many are watched at first, because some stop growing or shrink on their own.

Tests you may have

MRI

Uses magnets to make detailed pictures. It is the best scan for a lump in an arm or leg. It should be done before any biopsy.

CT scan

A detailed X-ray. A CT of the chest checks the lungs, the most common place sarcoma spreads. A CT of the belly is used for tumors there.

PET-CT or bone scan

These scans help show if cancer has spread, especially for bone sarcomas like Ewing sarcoma and osteosarcoma.

Core needle biopsy

A hollow needle takes small pieces of the tumor. It should be planned by the sarcoma team, because the biopsy path may need to be removed later during surgery.

Expert pathology review

Sarcomas are hard to diagnose. A pathologist who sees many sarcomas should look at your tissue to confirm the exact type and grade.

Gene and fusion testing

Many sarcomas have a gene change or fusion (two genes stuck together) that helps confirm the type. Some changes, like in GIST, guide treatment.

Heart test

Some chemotherapy can affect the heart. You may have an echocardiogram (an ultrasound of the heart) before starting.

Blood tests

These check your blood counts, kidneys, and liver. They help plan treatment and watch for side effects.

What the stage and grade mean

The grade tells how fast the sarcoma is likely to grow and spread. It is one of the most important facts about your sarcoma. Low grade grows slowly. High grade grows faster.

The stage combines the grade with the size of the tumor. It also shows if it has spread to lymph nodes or other organs. Lymph node spread is rare in most sarcomas.

GIST uses a risk level instead, based on tumor size, where it started, and how fast the cells are dividing.

Stage 1

Low-grade sarcoma that has not spread. Surgery alone is often enough.

Stage 2

Higher-grade sarcoma that is smaller and has not spread. Surgery is often combined with radiation.

Stage 3

Higher-grade sarcoma that is larger. For sarcoma in the back of the belly, spread to nearby lymph nodes is also stage 3. Treatment often combines surgery and radiation, and sometimes chemotherapy.

Stage 4

The sarcoma has spread to distant places, most often the lungs. For sarcoma in an arm, leg, or the trunk, spread to lymph nodes is also stage 4. Treatment uses medicines that travel through the body. Some people can have surgery to remove spots in the lungs.

GIST risk level

GIST is grouped as very low, low, intermediate, or high risk of coming back after surgery. People at high risk are usually offered a targeted pill after surgery.

Tumor markers and gene tests

Many sarcomas have their own gene changes. These help doctors name the exact type of sarcoma.

For some types, the gene change also points to a treatment. Ask your care team which tests were done and what they mean for you.

KIT and PDGFRA

Gene changes found in most GISTs. They decide which targeted pill works best. One PDGFRA change (D842V) does not respond to imatinib, but another pill, avapritinib, works well.

SDH

Some GISTs lack these proteins. They are more common in younger people, and standard pills work less well. Inherited testing may be advised.

MDM2

Extra copies of this gene are a sign of well-differentiated or dedifferentiated liposarcoma. It helps confirm the diagnosis.

Fusion genes

Many sarcomas have a fusion that helps confirm the type. Examples are EWSR1 in Ewing sarcoma and SS18 in synovial sarcoma.

MAGE-A4 and HLA type

A tumor protein and an immune type marker. Together they show if someone with synovial sarcoma can get a cell therapy called afami-cel.

NTRK

A rare gene fusion found in some sarcomas. Targeted pills can work very well when it is present.

Inherited gene testing

Some sarcomas are linked to inherited gene changes, such as TP53 (Li-Fraumeni syndrome), NF1, or RB1. A genetic counselor can help you and your family understand testing.

Main treatments

Surgery

The main treatment for most sarcomas that have not spread. The surgeon removes the tumor with a rim of healthy tissue around it (a clear margin). This lowers the chance it comes back.

Limb-sparing surgery

Most people with sarcoma in an arm or leg can keep the limb. Removing the tumor, often with radiation, works as well as amputation for most people. Some may need bone or joint replacement or reconstruction.

Radiation therapy

High-energy beams that kill cancer cells. It is often given before or after surgery for larger or higher-grade sarcomas to lower the chance the cancer comes back.

Chemotherapy

Medicines that kill fast-growing cells. It is a key part of treatment for Ewing sarcoma, osteosarcoma, and rhabdomyosarcoma. For other sarcomas, it is used for some high-risk tumors and for cancer that has spread.

Targeted therapy

Pills that block signals the cancer needs to grow. Imatinib and other pills are the main treatment for GIST. Other targeted pills are used for some soft tissue sarcomas and desmoid tumors.

Immunotherapy and cell therapy

Medicines that help the immune system fight cancer work for a few sarcoma types. A cell therapy made from your own immune cells is approved for some people with synovial sarcoma.

Surgery for lung spots

If sarcoma spreads to only a few spots in the lungs, removing them may help some people. Ask if this is an option for you.

Active surveillance

Some slow-growing tumors, like many desmoid tumors and small low-grade cartilage tumors, can be watched with regular scans before treatment.

Clinical trials

Because sarcomas are rare, clinical trials are an important way to get new treatments. Sarcoma centers often have trials. Ask if one is right for you.

Rehab

Physical and occupational therapy help you regain strength and use of your arm or leg after surgery. Some people use a prosthesis (artificial limb) or brace.

Common side effects and what helps

Fatigue

Feeling very tired is common. Light activity like short walks can help. Rest when you need to, and ask others for help.

Wound healing problems

Radiation before surgery can make the wound slower to heal. Keep the area clean and follow care instructions. Call about redness, opening, or fluid from the wound.

Stiffness and swelling

Radiation and surgery can cause stiffness or swelling in a limb. Stretching and physical therapy help. A compression sleeve or stocking may help with swelling.

Low blood counts and infection

Chemotherapy can lower your white blood cells. Wash your hands often and avoid sick people. Call right away if you have a fever.

Nausea

Anti-nausea medicines work well. Take them as directed, even before you feel sick. Eat small meals and sip fluids.

Hair loss

Many sarcoma chemotherapy medicines cause hair loss. It usually grows back after treatment. A soft hat or scarf can help.

Bladder and kidney effects

Ifosfamide, a common sarcoma medicine, can irritate the bladder and kidneys. Drink plenty of fluids as directed. Tell your team about blood in your urine or confusion.

Swelling and muscle cramps on imatinib

Puffy eyes, swelling in the legs, and muscle cramps are common. Take the pill with food and water. Tell your team, because there are ways to help.

Skin and blood pressure changes on targeted pills

Some pills cause sore, red hands and feet or high blood pressure. Use thick moisturizer and avoid tight shoes. Check your blood pressure as your team advises.

Living with and after sarcoma

You will have regular checkups and scans after treatment, often for many years. These usually include scans of the area where the tumor was and of your chest.

Rehab is a big part of recovery after limb surgery. Physical and occupational therapists can help you walk, work, and do daily tasks. Many people return to their usual activities.

Some chemotherapy can affect the heart, hearing, kidneys, or fertility later on. Ask your team what long-term checks you need. If you may want children, ask about storing eggs or sperm before treatment.

Some sarcomas, like bone sarcomas, are more common in teens and young adults. There are programs that support young people with cancer. Ask about school, work, and peer support.

Because sarcoma is rare, it can feel lonely. Sarcoma support groups, online and in person, can connect you with others who understand. Caregivers can find support too.