Sarcoma is a rare type of cancer that starts in the bones or the soft tissues. Sarcomas are generally grouped into two broad categories: bone cancer sarcomas and soft tissue sarcoma. Soft tissues connect, support and surround other structures in the body and include muscle, fat, blood vessels, nerves, tendons and other connective tissues.

Sarcomas are different from carcinomas, which make up most cancers in adults. Carcinomas usually start in the cells that make up or line the organs. Sarcomas start in the soft tissues or the bones. This difference is important because sarcomas and carcinomas can behave differently and may need different approaches to diagnosis and treatment.

Sarcomas are not common. They account for less than 1% of cancers diagnosed in adults. There are many different types of sarcomas, and treatment depends on the specific type, where the cancer started, its stage and other factors.

There are many types of sarcomas. Each type can behave differently and may require a different approach to diagnosis and treatment.

Some types of sarcomas don't fit neatly into one category. For example, Ewing sarcoma most often starts in bone but also can develop in soft tissue.

Some tumors start in soft tissues that connect and support, but they are not true sarcomas. Sarcoma specialists may treat these tumors, but they aren't always classified or treated in the same way as soft tissue sarcomas.

Bone sarcomas

• Osteosarcoma. Osteosarcoma starts in bone-forming cells. It most often develops in the long bones, particularly around the knee, and is most common in adolescents and young adults.
• Chondrosarcoma. Chondrosarcoma starts in cartilage-producing cells. It most often occurs in the pelvis, upper leg or shoulder and is more common in adults.
• Ewing sarcoma. Ewing sarcoma most often starts in bone but can start in soft tissue. It occurs most often in children, teenagers and young adults.

Soft tissue sarcomas

• Angiosarcoma. Angiosarcoma is a type of cancer that forms in the lining of the blood vessels and lymph vessels.
• Desmoplastic small round cell tumor (DSRCT). DSRCT is an aggressive sarcoma that usually starts in the abdomen or pelvis. It occurs most often in adolescents and young adults.
• Epithelioid sarcoma. Epithelioid sarcoma often starts in the hands, arms, feet or legs of teenagers and young adults. Other forms can start closer to the center of the body. Epithelioid sarcoma tends to grow slowly. It can come back after treatment.
• Kaposi sarcoma.This cancer can be caused by infection with the human herpes virus 8 (HHV-8) and is more likely to occur in people with weakened immune systems, including people with HIV. It also can happen in people who take medicines to prevent organ rejection after an organ transplant.
• Leiomyosarcoma. This cancer starts in smooth muscle tissue. Many areas of the body have smooth muscle tissue. Leiomyosarcoma most often starts in the uterus, belly or leg.
• Liposarcoma. Liposarcoma is a cancer that starts in the fat cells. It can happen anywhere in the body but occurs most often in the belly, arm or leg.
• Malignant peripheral nerve sheath tumor (MPNST). These tumors start in tissue that surrounds peripheral nerves. These nerves run from the spinal cord into the body. MPNST used to be called neurofibrosarcomas.
• Myxofibrosarcoma. This soft tissue sarcoma most often starts in the arms or legs of older adults. It can grow into surrounding tissues and often comes back in the same area after treatment.
• Rhabdomyosarcoma. This sarcoma starts in muscle tissue. It occurs most often in children and adolescents, although adults can develop it.
• Synovial sarcoma. This cancer tends to happen near large joints, mainly the knees. It usually affects young adults.
• Undifferentiated pleomorphic sarcoma (UPS). The name comes from the way the cancer cells appear under the microscope. Undifferentiated means the cells don't look like the body tissues in which they develop. The cancer is called pleomorphic (plee-o-MOR-fik) because the cells grow in multiple shapes and sizes.

Other related tumors

• Dermatofibrosarcoma protuberans (DFSP). DFSP is a type of skin cancer that starts in the connective tissue cells in the middle layer of the skin. It typically grows slowly but can grow into nearby tissues.
• Gastrointestinal stromal tumor (GIST). GIST is a type of cancer that begins in the digestive system. These tumors happen most often in the stomach and small intestine.
• Solitary fibrous tumor. These tumors start in the connective tissue and can develop almost anywhere in the body. They often occur in the lining around the outside of the lungs. They tend to grow slowly.

Symptoms may vary based on the type of sarcoma. Common signs and symptoms of sarcoma include:

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

Most lumps that develop are not sarcoma. Sometimes noncancerous lumps, called benign lumps, develop from fat cells. These are called lipomas.

But a lump that is growing, is larger than about 2 inches (5 centimeters) or is located deep beneath the skin should be checked by a healthcare professional. You can't tell whether a lump is a sarcoma simply by how it looks or feels.

When to see a doctor

Make an appointment with a doctor or other healthcare professional for symptoms that worry you.

Have a lump checked if it:

• Continues to grow.
• Is larger than about 2 inches (5 centimeters).
• Feels like it is deep beneath the skin.

A sarcoma lump may not hurt, so don't wait for a lump to become painful before having it checked.

Also make an appointment if you have swelling near a bone, or lasting bone pain or tenderness, especially pain that occurs at rest or at night. A broken bone that happens after little or no injury also should be evaluated.

It's not clear what causes most sarcomas. Most sarcomas occur sporadically, meaning they develop without a known cause or an inherited condition that explains why they occurred.

Sarcoma starts when cells in bone or soft tissues develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA gives instructions that help control when cells grow, multiply and die.

In cancer cells, the DNA changes give different instructions. These changes tell the cancer cells to grow and divide when they shouldn't or to keep living when healthy cells would die. This causes too many irregular cells to accumulate.

The cancer cells might form a mass called a tumor. The tumor can grow to invade and destroy healthy tissue. In time, cancer cells can break away and spread to other parts of the body. When cancer spreads, it's called metastatic cancer.

Researchers have identified certain factors that can increase the risk of developing some types of sarcoma. But having a risk factor doesn't mean you'll develop the disease.

Factors that can increase the risk of sarcoma include:

• Inherited syndromes. Some syndromes that raise the risk of cancer can pass from parents to children. For instance, syndromes that increase the risk of sarcoma include Li-Fraumeni syndrome, familial retinoblastoma and neurofibromatosis type 1.
• Radiation therapy for cancer. Radiation treatment for cancer raises the risk of getting a sarcoma later.
• Lymphedema. Lymphedema is swelling that happens when something blocks or damages the lymphatic system. Lymphedema raises the risk of a type of sarcoma called angiosarcoma.
• Exposure to viruses. Human herpes virus 8 (HHV-8) causes Kaposi sarcoma. The risk is higher in people with weakened immune systems, including people with HIV.

Sarcoma diagnosis often begins with a physical exam. This cancer starts in the bones or soft tissues. The tests you have may depend on the part of your body that's affected. Other tests may include imaging tests and a procedure to remove a sample of cells for testing.

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.

Imaging tests

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. Imaging tests may include:

• X-ray.
• Magnetic resonance imaging (MRI).
• Computerized tomography (CT) scan.
• Positron emission tomography (PET) scan.
• Bone scan.

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, are better for seeing connective tissues.

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.

Biopsy requires careful planning by your medical team. Healthcare professionals need to perform the biopsy in a way that won't interfere with future surgery to remove the cancer. Whenever possible, the biopsy should be performed by the team that will treat the sarcoma.

The tissue sample should be reviewed by a pathologist with experience diagnosing sarcomas. There are many types of sarcoma, and determining the specific type can be complex. The pathologist examines the tissue and may use additional lab tests to help make an accurate diagnosis. Identifying the type of sarcoma is important because it can affect treatment decisions.

Grades

Grade describes what the cancer cells look like under the microscope and how aggressively the tumor is likely to behave. These factors are combined into a grade.

• Grade 1: Low grade. The cancer tends to grow and spread more slowly.
• Grade 2: Intermediate grade.
• Grade 3: High grade. The cancer is more likely to grow and spread.

The way sarcomas are graded depends on the specific type of sarcoma. A single grading system may not apply to every sarcoma subtype.

For many soft tissue sarcomas, a pathologist assigns a grade based on features seen under a microscope. Grading considers features such as how the cells look, how many cells are dividing, and how much tumor tissue is dying, called necrosis.

In general, a higher grade means the cancer is more likely to grow quickly or spread. Grade is one of several factors your care team considers when estimating your outlook and recommending treatment.

Sarcoma treatment depends on the type of sarcoma, where it started, its grade and stage, and whether it has spread. The goal of treatment also varies.

For a localized sarcoma, treatment may aim to remove or destroy all the cancer and cure it. When a sarcoma can't be completely removed or has spread to other parts of the body, treatment may focus on controlling the cancer, slowing its growth and helping you live longer.

Treatment also may be used to relieve pain or other symptoms caused by the cancer. Because different types of sarcoma can respond differently to treatment, the combination and order of surgery, radiation therapy, chemotherapy and other medicines vary from person to person.

Surgery

The goal of surgery for sarcoma is to remove all the cancer cells. Sometimes surgeons need to remove a limb, such as an arm or a leg, to get all the cancer. This is called amputation. But surgeons try to save the limb when they can.

Sometimes surgeons can't remove all the cancer without hurting nearby nerves or organs. In those instances, the surgeons consider the balance between tumor removal, function and other potential treatments.

Radiation therapy

Radiation therapy treats cancer with powerful energy beams. The energy can come from X-rays, protons or other sources.

For sarcoma, you might have radiation therapy before, during or after surgery to remove the cancer.

Chemotherapy

Chemotherapy treats cancer with strong medicines. Some types of sarcoma are more likely to respond to chemotherapy treatment than are others. Healthcare professionals might use chemotherapy before or after surgery. It also can help treat sarcoma that spreads to other parts of the body.

Targeted therapy

Targeted therapy for cancer is a treatment that uses medicines that attack specific chemicals in the cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die.

Your healthcare professional may have your sarcoma cells tested to see if they are likely to respond to targeted therapy medicines. Targeted therapy may treat certain types of sarcoma. It might be used if the cancer comes back or spreads.

Immunotherapy

Immunotherapy for cancer is a treatment with medicine that helps the body's immune system kill cancer cells. The immune system fights off diseases by attacking germs and other cells that shouldn't be in the body. Cancer cells survive by hiding from the immune system. Immunotherapy helps the immune system cells find and kill the cancer cells.

For some sarcomas, tumor testing may help determine whether immunotherapy could be an option. This treatment might help control some sarcoma types that have spread to other parts of the body.

Ablation therapy

Ablation is a procedure that applies treatment directly to the cancer cells to harm them. Some types of ablation apply energy to the cancer cells that causes them to heat up. Procedures that do this include radiofrequency ablation and microwave ablation.

Using extreme cold to harm the cancer cells is called cryoablation.

Ablation might be used to treat sarcoma when surgery isn't an option. It also might be used when the cancer spreads to other parts of the body.

Palliative care

Palliative care focuses on relieving symptoms and improving quality of life at any stage of cancer. For advanced sarcoma, treatments such as surgery, radiation therapy or medicines also may be used to relieve symptoms even when eliminating the cancer isn't possible. Palliative care can be given with treatments intended to control the cancer.

Treatment side effects

Cancer treatment can cause side effects and complications. Surgery may affect movement and function, and some people need rehabilitation after treatment. Radiation therapy can cause wound-healing problems. Over time, it can cause tissue scarring, swelling called lymphedema or joint stiffness. Chemotherapy and other medicines can cause side effects that vary depending on the drugs used. Your healthcare team can explain the short- and long-term effects that are most likely with your treatment plan.

With time, you'll find what helps you cope with your sarcoma diagnosis. Until then, you may find that it helps to:

Learn enough about sarcoma to make decisions about your care

Ask your healthcare team about your cancer. Ask about your test results and the treatments you might have.

If you like, ask about the likely outcome of your condition with and without treatment. As you learn more about cancer, you may feel better about making treatment decisions.

Keep friends and family close

Strong relationships can help you deal with your cancer. Friends and family can give you the help you need. For instance, they can take care of your home if you're in the hospital. They can serve as emotional support when you feel like your cancer is too much to handle.

Find someone to talk with

Find a good listener who is willing to hear you talk about your condition. This may be a friend or family member. A counselor, medical social worker, clergy member or cancer support group also may be helpful.

Ask your healthcare team about support groups in your area. In the United States, look to the National Cancer Institute and the American Cancer Society for more information.

Start by making an appointment with a doctor or other healthcare professional if you have symptoms that worry you.

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do in advance, such as fasting before having a certain test. Make a list of:

• Your symptoms, including symptoms that don't seem linked to the reason for your appointment, and when they began.
• Key personal information, including major stresses, recent life changes and family medical history.
• All medications, vitamins or other supplements you take, including the doses.
• Questions to ask your healthcare team.

Bring a family member or friend with you, if possible, to help you remember the information you're given.

For sarcoma, some basic questions to ask include:

• What's likely causing my symptoms?
• Other than the most likely cause, what are other possible causes for my symptoms?
• What tests do I need?
• What's the best course of action?
• I have other health conditions. How can I manage them together?
• Should I see a specialist?
• Are there brochures or other printed materials I can have? What websites do you suggest?

Be sure to ask all the questions you have.

What to expect from your doctor

Your healthcare team is likely to ask you questions, such as:

• Do you have your symptoms all the time or do they come and go?
• How bad are your symptoms?
• What, if anything, seems to make your symptoms better?
• What, if anything, appears to make your symptoms worse?

Stage describes how much cancer there is and how far it has spread. For soft tissue sarcoma, stages generally range from 1 to 4. A lower stage generally means the cancer is more limited. A higher stage means it is more advanced.

Healthcare professionals determine the stage using several pieces of information, commonly summarized as TNM plus grade. TNM stands for:

• T: The size of the primary tumor.
• N: Whether the cancer has spread to nearby lymph nodes.
• M: Whether the cancer has spread to distant parts of the body.

Staging isn't identical for every sarcoma. The tumor's location and type matter, and bone sarcomas have their own staging considerations. So a person's sarcoma can't necessarily be assigned a stage from tumor size alone.

Both tumor grade and stage help the care team understand the likely outcome of your condition, called prognosis, and determine the most appropriate treatment.

Cancer survival rates or survival statistics tell you the percentage of people who survive a certain type of cancer for a specific amount of time. Statistics can vary by sarcoma type, location, grade, stage, age and other factors.

Many people wonder about survival rates by numbered stages, such as 1 to 4. But the U.S. National Cancer Institute (NCI), which tracks cancer survival rates in the United States, reports the rates by how far the cancer has spread.

The categories for NCI survival rates are:

• Localized: The cancer is limited to the part of the body where it started.
• Regional: The cancer has spread to nearby structures or nearby lymph nodes.
• Distant: The cancer has spread to distant areas of the body, such as to the lungs.

Cancer statistics often use a five-year relative survival rate. This rate compares survival among people with the cancer and survival among people in the general population.

For soft tissue sarcomas, the 5-year relative survival rate is about 83% for localized cancer, 60% for regional cancers and 17% if the cancer has distant spread.

For bone and joint cancers overall, the five-year relative survival rate is about 69%. Survival for bone sarcomas varies depending on the type of bone cancer and whether it has spread.

Survival statistics describe large groups of people. They can't predict what will happen for any one person. If you want to know the survival rate for your bone cancer, talk about it with your healthcare team. Your care team can tell you about the prognosis for someone in your particular situation. Team members also know more about you and your cancer and can explain what may affect your personal outlook.