Sarcoma

What is Sarcoma?

Cancerous (malignant) tumors of the connective tissues are called “sarcomas”. The term sarcoma comes from a Greek word meaning fleshy growth. Sarcoma arises in the connective tissue of the body. Normal connective tissue include, fat, blood vessels, nerves, bones, muscles, deep skin tissues, and cartilage. Sarcomas are divided into two main groups, bone sarcomas and soft tissue sarcomas. They are further sub­classified based on the type of presumed cell of origin found in the tumor. They all share certain microscopic characteristics and have similar symptoms. Sarcomas can develop in children and adults. For children under 20 approximately 15 percent of cancer diagnosis are sarcomas. Although rare, there are approximately 14,000 new cases of sarcoma diagnosed each year in the United States. In general sarcomas are divided into the large groups of soft tissue sarcoma and bone sarcomas.

Sarcoma: Detection & Treatment Options

People with a strong family history of sarcomas or other cancers occurring at a young age may wish to discuss the benefits and disadvantages of genetic testing with their doctor. The genetic testing results should always be explained by a genetic counselor or a specially trained doctor who can interpret the results and advise high­risk patients about early cancer detection.

Families with a history of certain inherited conditions caused by mutated tumor suppressor genes have an increased risk of developing soft tissue sarcomas. The mutated genes can be detected by genetic testing, so family members should discuss this option with their doctors. They should let their doctor know about any lumps or growths right away.

No screening tests and exams are recommended for people who have no family history of sarcoma or other sarcoma risk factors. For these people, the best approach to early detection is to notify their health care professional of any unexplained lumps or growths or other symptoms that may be caused by a soft tissue sarcoma.

Treatment

The only way to cure a soft tissue sarcoma is to remove it with surgery, so surgery is part of the treatment for all soft tissue sarcomas whenever possible. It is important that your surgeon and other doctors are experienced in the treatment of sarcomas. These are difficult tumors to treat and require both experience and expertise. Studies have shown that patients with sarcomas have better outcomes when they are treated at specialized cancer centers that have experience in sarcoma treatment.

Desmoid tumors

Desmoid tumors act differently from most soft­tissue sarcomas in that although they can grow into nearby tissues and often come back after surgery, they rarely spread to distant sites.

Some desmoid tumors can be watched without treatment for a time. Treatment will be given if the tumor is growing or is causing pain or other symptoms.

If treatment is needed and the entire tumor can be removed, the first treatment is often surgery. If the entire tumor is removed and the margins are clear, no other treatment is needed. These tumors can also be treated with radiation (instead of surgery).

For tumors that are large or have come back after treatment, drug therapy may be helpful. The drug sulindac, normally used to treat arthritis, can stop tumor growth or even cause the tumor to shrink. It can take months for the drug to work, but its effect can last for years. Drugs that block estrogen (tamoxifen and toremifene) have also been helpful in some patients. Some desmoid tumors have responded to treatment with chemotherapy (chemo) using the drug doxorubicin (Adriamycin), which may be used alone or with other drugs. The combination of methotrexate and vinblastine has also been helpful. Interferon, an immune­boosting drug, has also been used with some success. Another option is the targeted drug imatinib (Gleevec).

Stage I soft tissue sarcoma

Stage I soft tissue sarcomas are low­grade tumors of any size. Small (less than 5 cm or about 2 inches across) tumors of the arms or legs may be treated with surgery alone. The goal of surgery is to remove the tumor with some of the normal tissue around it. If cancer cells are found in or near the edges of the tissue removed (called positive or close margins), it can mean that some cancer was left behind. Often the best option for positive or close margins is more surgery. Another option is treating with radiation therapy after surgery. This lowers the chance of the cancer coming back.

If the tumor is not in a limb, (for example it is in the head, neck, or abdomen), removing the entire tumor with enough normal tissue around it can be more difficult. For these tumors, radiation with or without chemo may be given before surgery. This may be able to shrink the tumor enough to remove it entirely with surgery. If radiation is not used before surgery, it may be given after surgery to lessen the chance that the tumor will come back.

Stages II and III soft tissue sarcoma

Some stage III tumors have already spread to nearby lymph nodes. Most stage II and III sarcomas are high­grade tumors. They tend to grow and spread quickly. Even when these sarcomas have not yet spread to lymph nodes, the risk of spread (to lymph nodes or distant sites) is very high. These tumors also tend to grow back in the same area after they are removed (this is called local recurrence).

For all stage II and III sarcomas, surgically removing the tumor is still the main treatment. Lymph nodes will be removed as well if they contain cancer. If the tumor is large or in a place that would make surgery difficult, the patient may be treated with chemo, radiation, or both before surgery. For large tumors in the arms or legs, giving chemo by isolated limb perfusion is also an option. The goal of treatment is to shrink the tumor, making it easier to remove. These treatments also lower the chance of the tumor coming back in or near the same place it started. Smaller tumors may be treated with surgery first, then radiation to lower the risk of the tumor coming back. Sometimes chemo is given as well. When chemo is given, the drug most often used is doxorubicin (Adriamycin). This drug may be combined with ifosfamide (Ifex) and other drugs.

In rare cases, amputation is needed to remove the entire tumor. As with stage I sarcomas, radiation therapy with or without chemo can be used alone when the tumor’s location or size or the patient’s health in general makes surgery impossible. There is evidence that chemo after surgery may benefit some people with stage II and III sarcomas.

Stage IV soft tissue sarcoma

A sarcoma is considered stage IV when it has spread to distant sites (M1). Stage IV sarcomas are rarely curable. But some patients may be cured if the main tumor and all of the areas of cancer spread (metastases) can be removed by surgery. The best success rate is when it has spread only to the lungs. This is still an area where doctors disagree about which patients will benefit. Those patients’ main tumors should be treated as in stages II or III, and metastases should be completely removed, if possible.

For patients whose primary tumor and all metastases cannot be completely removed by surgery, radiation therapy and/or chemotherapy are often given to relieve symptoms. The chemo drugs doxorubicin and ifosfamide are often the first choice — either alone or together with other drugs. Gemcitabine and docetaxel may be given if the first combination stops working (or doesn’t work). Patients with angiosarcomas may benefit from treatment with paclitaxel (Taxol) or docetaxel (Taxotere) with vinorelbine (Navelbine).

Recurrent sarcoma

Cancer is called recurrent when it come backs after treatment. Recurrence can be local (in or near the same place it started) or distant (spread to other organs or tissues such as the lungs or brain). If the sarcoma comes back in the same area where it started, it may be treated with surgery. Radiation therapy is another option, especially if radiation wasn’t part of the treatment of the original tumor. If external beam radiation was used before, brachytherapy may still be an option.

If the sarcoma returns at a distant site, chemo may be given. If the sarcoma has spread only to the lungs, it may be possible to remove all the areas of spread with surgery. Radiation is used to treat sarcomas that spread to the brain, as well as any recurrences that cause symptoms such as pain.

Sarcoma: Types & Stages

There are many types of soft tissue tumors, and not all of them are cancerous. When the term sarcoma is part of the name of a disease, it means the tumor is malignant (cancer). Some soft tissue tumors behave in way in between a cancer and a non­cancer. These are called intermediate.

There are about 50 different types of soft tissue sarcomas (not all are listed here), such as:

  • Adult fibrosarcoma
  • Alveolar soft­part sarcoma
  • Angiosarcoma (includes hemangiosarcoma and lympangiosarcoma)
  • Clear cell sarcoma
  • Desmoplastic small round cell tumor
  • Epithelioid sarcoma
  • Fibromyxoid sarcoma, low­grade
  • Gastrointestinal stromal tumor (GIST): this is a type of sarcoma that develops in the digestive tract. It is covered in a separate document, Gastrointestinal Stromal Tumor (GIST).
  • Kaposi sarcoma: this is a type of sarcoma that develops from the cells lining lymph or blood vessels. It is covered in a separate document, Kaposi Sarcoma
  • Liposarcoma (includes dedifferentiated, myxoid, and pleomorphic liposarcomas)
  • Leiomyosarcoma
  • Malignant mesenchymoma
  • Malignant peripheral nerve sheath tumors (includes neurofibrosarcomas, neurogenic sarcomas, and malignant schwannomas)
  • Myxofibrosarcoma, low­grade
  • Rhabdomyosarcoma: this is the most common type of soft tissue sarcoma seen in children and is discussed in the separate document Rhabdomyosarcoma.
  • Synovial sarcoma
  • Undifferentiated pleomorphic sarcoma (previously known as malignant fibrous histiocytoma or MFH)

Many of these types are discussed in more detail later in this section. There are many other types of tumors called soft tissue sarcomas, but these are all quite rare.

Intermediate soft­tissue tumors include:

  • Dermatofibrosarcoma protuberans
  • Fibromatosis (also known as desmoid tumor, musculoaponeurotic fibromatosis, and aggressive fibromatosis
  • Hemangioendothelioma
  • Infantile fibrosarcoma
  • Solitary fibrous tumor

Grade (G)

The grade is a sign of how likely it is the cancer will spread. Previously, the grade of a sarcoma was only based on how normal the cells looked under the microscope (called differentiation). This was not very helpful, and under a new system (known as the French or FNCLCC system), grade is based on 3 factors:

  • Differentiation: Cancer cells are given a score of 1 to 3, with 1 being assigned when they look similar to normal cells and 3 being used when the cancer cells look very abnormal. Certain types of sarcoma are given a higher score automatically.
  • Mitotic count: How many cancer cells are seen dividing under the microscope; given a score from 1 to 3 (a lower score means fewer cells were seen dividing)
  • Tumor necrosis: How much of the tumor is made up of dying tissue; given a score from 0 to 2 (a lower score means there was less dying tissue present).

The scores for each factor are added to determine the grade for the cancer. Higher­grade cancers tend to grow and spread faster than lower­grade cancers.

GX: The grade cannot be assessed (because of incomplete information).

Grade 1 (G1): Total score of 2 or 3

Grade 2 (G2): Total score of 4 or 5

Grade 3(G3): Total score of 6 or higher Tumor (T)

T1: The sarcoma is 5 cm (2 inches) or less across

  • T1a:The tumor is superficial (near the surface of the body).
  • T1b: The tumor is deep in the limb or abdomen.

T2: The sarcoma is greater than 5 cm (2 inches) across.

  • T2a:The tumor is superficial (near the surface of the body).
  • T2b:The tumor is deep in the limb or abdomen.

Lymph nodes (N)

N0: The sarcoma has not spread to nearby lymph nodes.

N1: The sarcoma has spread to nearby lymph nodes.

Metastasis (M)

M0: No distant metastases (spread) of sarcoma are found.

M1: The sarcoma has spread to distant organs or tissues (such as the lungs).

Stage grouping for soft tissue sarcomas

To assign a stage, information about the tumor, its grade, lymph nodes, and metastasis is combined by a process called stage grouping. The stage is described by Roman numerals from I to IV and the letters A or B. The stage is useful in selecting treatment, but other factors, such as where the sarcoma is located, also influence treatment planning and outlook.

Stage IA

T1, N0, M0, G1 or GX: The tumor is not larger than 5 cm (2 inches) across (T1). It has not spread to lymph nodes (N0) or more distant sites (M0). The cancer is grade 1 (or the grade cannot be assessed).

Stage IB

T2, N0, M0, G1 or GX: The tumor is larger than 5 cm (2 inches) across (T2). It has not spread to lymph nodes (N0) or more distant sites (M0). The cancer is grade 1 (or the grade cannot be assessed).

Stage IIA

T1, N0, M0, G2 or G3: The tumor is not larger than 5 cm (2 inches) across (T1). It has not spread to lymph nodes (N0) or more distant sites (M0). The cancer is grade 2 or 3.

Stage IIB

T2, N0, M0, G2: The tumor is larger than 5 cm (2 inches) across (T2). It has not spread to lymph nodes (N0) or more distant sites (M0). The cancer is grade 2.

Stage III

Either

T2, N0, M0, G3: It is larger than 5 cm (2 inches) across (T2). It has not spread to lymph nodes (N0) or more distant sites (M0). The cancer is grade 3.

OR

Any T, N1, M0, any G: The cancer can be any size (any T) and any grade (any G). It has spread to nearby lymph nodes (N1). It has not spread to distant sites (M0).

Stage IV

Any T, Any N, M1, any G: The cancer can be any size (any T) and grade (any G). It has spread to lymph nodes near the tumor (N1) and/or to distant sites (M1).

Sarcoma: FAQs

Answer :

A sarcoma is a tumor of your connective tissue including muscle, fat, bone, blood vessels, cartilage and other connective tissues.

Answer :

The most common cancers are carcinomas and include breast, prostate, lung, and colon cancer. Cancers of the blood and immune system are are leukemias and lymphomas. These are different cancers from sarcomas.

Answer :

It is unclear how most sarcomas arise. Some patients can have a familial syndrome that can lead to a sarcoma, but these are rare cases.

Answer :

Sarcomas are cared for by teams of doctors. At UCLA, we have a group of surgeons, pathologists, medical oncologists, radiation oncologists and radiologists who take care of sarcoma patients.