Soft-Tissue Sarcoma

There are more than 50 different types of soft-tissue sarcoma. They are classified according to the tissue of origin.

Major types include:

• Undifferentiated Pleomorphic Sarcoma (UPS): UPS can occur anywhere in the body. It is usually seen in the arms, legs (especially thighs) and behind the abdominal cavity (retroperitoneum). These tumours often grow rapidly and can spread to other parts of the body, including the lungs. Other names for UPS include malignant fibrous histiocytoma and myxofibrosarcoma.
• Leiomyosarcoma: Leiomyosarcoma affects smooth muscle tissue and is most commonly seen in the abdomen. It usually occurs in the uterus but can also form in the bladder and stomach. Leiomyosarcoma can also affect large blood vessels (such as the inferior vena cava and pulmonary artery).
• Liposarcoma: Liposarcoma arises from fatty tissues, usually in the arms, legs or abdomen. There are many different sub types of liposarcoma and some can be more aggressive than others.
• Gastrointestinal stromal tumor (GIST): Arise in specialized nerve cells of the digestive tract and are most commonly seen in the stomach and small intestine. For more in depth information about GIST, please visit Cancer.Net.

The cause of most soft tissue sarcomas is largely unknown, although the following factors can increase the risk of developing sarcoma:

• Previous radiation therapy/ exposure: People who have been treated with radiation therapy have a slightly increased risk of later developing sarcoma.
• Genetics: Certain inherited genetic conditions can increase the risk of developing sarcoma. These diseases include hereditary retinoblastoma; Li-Fraumeni syndrome; Gardner syndrome; Werner syndrome; tuberous sclerosis; neurofibromatosis type 1; familial adenomatous polyposis and nevoid basal cell carcinoma syndrome.
• Chemicals: Workplace exposure to vinyl chloride monomer, which is used to make certain types of plastics, arsenic, Agent Orange, or dioxin, may increase the risk of developing sarcoma. However, most sarcomas are not known to be associated with specific environmental hazards.

Mount Sinai Hospital and the Lunenfeld-Tanenbaum Research Institute are dedicated to clinical and translational research and our scientists are working to learn more about sarcoma, how to best treat it, and how to provide the best care.

Depending on the location, symptoms and signs of soft-tissue sarcoma include:

• A lump anywhere on the body, especially if it’s larger than five centimeters, is growing larger or is causing pain
• Feeling of fullness (for tumours in the abdomen)
• Pain in the abdomen, pelvis, back
• Black or bloody stool or vomiting blood (digestive tract)
• Abnormal uterine bleeding
• Chest pains or trouble breathing (chest)

The following imaging studies may be used in conjunction with the clinical examination by your doctor to investigate a probable diagnosis of sarcoma:

• X-ray
• Ultrasound
• CT
• MRI
• Bone scans
• PET scans

The diagnosis is confirmed by the results of a biopsy. A biopsy is a sample of tissue that is removed and examined microscopically by a pathologist.

Because soft tissue sarcomas are uncommon and there are many different types, it is important to have an expert pathologist or specialist with sarcoma experience review the tissue sample to make the appropirate diagnosis. It is important for surgeons who have expertise with sarcoma to perform the surgery. It is also important for medical and radiation oncologists with sarcoma experience to plan therapies other than or in addition to surgery.

Your health care team will offer you treatment options and recommendations based on several factors, including the type, stage, and grade of sarcoma, possible side effects, your preferences and overall health. Your care plan may also include treatment of symptoms and side effects which is an important part of cancer care.

Treatment for soft tissue sarcoma may include a combination of surgery, radiation and/or chemotherapy.

Surgery

Surgery is the main treatment for most soft tissue sarcomas. The tumour is removed along with some surrounding healthy tissue during an operation.

Surgical oncologists and orthopaedic oncologists are doctors who specialize in the surgical treatment of soft tissue sarcomas.

High grade soft tissue sarcomas that are larger than two inches (five centimetres) are often treated with a combination of surgery and radiation therapy.

Radiation therapy or chemotherapy may be given prior to surgery to shrink the tumour and make surgical removal easier. These treatments may also be given after surgery to destroy any cancer cells that may still exist.

Common surgical options:

• Wide local excision removes the tumour with a margin of healthy tissue around the tumour to ensure all cancer cells have been removed.
• Limb-sparing surgeries remove the tumour from an arm or a leg (limb) without removing the whole arm or leg and preserving nearby vessels and nerves.
• Reconstructive surgery uses tissue from another part of the body in the form of muscle flaps and skin grafts to be used over areas of reconstruction to help with healing and reduce the risk of infection.
• Amputation, although rare for soft tissue sarcoma, maybe the best option for the treatment depending on the size and/or location of the tumour, and involvement of nearby vessels, muscles or nerves. These include cases when the tumour cannot be completely removed with surgery, when reconstruction is not possible or if cancer comes back in the same area after limb-sparing surgery.

Radiation

Radiation treatment is prescribed by a radiation oncologist. Radiation is generally given over consecutive treatments for days.

Chemotherapy

Chemotherapy is prescribed by a medical oncologist, a doctor who specializes in treating cancer with medication. It may be given alone or in combination with surgery, radiation therapy, or both.

Targeted Therapy

Targeted therapy is treatment with a medicine that targets and interferes with the tumour’s specific proteins, genes or other factors that promote cancer growth and survival. It will block the growth and spread of cancer cells and limits damage to healthy cells. Your doctor may have your cancer cells tested to see if they may respond to targeted therapy drugs. Targeted therapy has been helpful in the treatment of gastrointestinal stromal tumours (GIST).

• The Canadian Cancer Society has some more in-depth information on soft-tissue sarcoma. 
• Sarcoma Cancer Foundation of Canada
• Toronto Sarcoma Program (webpage currently under development)