A sarcoma is a type of cancer that usually develops from certain tissues like, within the bone or muscle. Bone and soft tissue sarcomas are the main types. Soft tissue sarcomas are a group of cancers that grow in parts of your body such as your muscles, bones, deep layers of skin, or in fat. Additionally, they can also occur in blood vessels, nerves or connective tissues, which support organs and other kinds of tissues. While they can happen in any part of the body, the most common locations are arms, legs and abdomen. Soft tissue sarcomas are rare and account for less than 1% of all cancer cases. There are however, dozens of different types of soft tissue sarcomas and they can happen in children and adults. The most common types of soft tissue sarcomas are:
- Angiosarcoma: Angiosarcoma is a rare type of cancer that forms in the lining of the blood vessels and lymph vessels. Angiosarcoma can occur anywhere in your body, but it most often occurs in the skin on your head and neck.
- Dermatofibrosarcoma protuberans: Dermatofibrosarcoma protuberans (DFSP) is a very rare type of skin cancer that begins in connective tissue cells in the middle layer of your skin (dermis). Dermatofibrosarcoma protuberans may at first appear as a bruise or scar. As it grows, lumps of tissue (protuberans) may form near the surface of the skin. This skin cancer often forms on the arms, legs and trunk.
- Epithelioid Sarcoma: Epithelioid sarcoma is a rare, slow-growing type of soft tissue cancer. Most cases begin in the soft tissue under the skin of a finger, hand, forearm, lower leg or foot, though it can start in other areas of the body. Typically, epithelioid sarcoma starts as a small firm growth or lump that’s painless. It usually starts out as a single growth, but multiple growths may occur.
- Gastrointestinal Stromal Tumour (GIST): These are soft-tissue sarcomas that can be located in any part of the digestive system. Their most common sites are the stomach and small intestine. GISTs start in specialized nerve cells located in the walls of your digestive system. These cells are part of the autonomic nervous system. A specific change in the DNA of one of these cells, which control such digestive processes as movement of food through the intestines, gives rise to a GIST.
- Kaposi’s Sarcoma: is a type of cancer that forms in the lining of blood and lymph vessels. The tumours (lesions) of Kaposi’s sarcoma typically appear as painless purplish spots on the legs, feet or face. Lesions can also appear in the genital area, mouth or lymph nodes. In severe Kaposi’s sarcoma, lesions may develop in the digestive tract and lungs.
- Leiomyosarcoma: Leiomyosarcoma is a rare type of cancer that affects smooth muscle tissue. These tumours are most common in the abdomen, but can occur anywhere in the body, including the uterus. Other common sites include blood vessels and skin.
- Liposarcoma: Liposarcoma can occur in fat cells in any part of the body, but most cases occur in the muscles of the limbs or in the abdomen. Liposarcoma occurs most often in older adults, though it can occur at any age.
- Malignant Peripheral Nerve Sheath Tumours: Malignant peripheral nerve sheath tumours are a rare type of cancer that occurs in the lining of the nerves that extend from the spinal cord into the body. Malignant peripheral nerve sheath tumours used to be called neurofibrosarcomas. Malignant peripheral nerve sheath tumours can occur anywhere in the body, but most often occur in the deep tissue of the arms, legs and trunk. They tend to cause pain and weakness in the affected area and may also cause a growing lump or mass.
- Myxofibrosarcoma: Myxofibrosarcoma (MFS) is a type of cancer that typically appears as a slow-growing, painless lump on one of your legs or arms. The disease occurs mainly in people between the ages of 50 and 70 and is slightly more common in men than in women.
- Rhabdomyosarcoma: Rhabdomyosarcoma (RMS) is a rare cancer that forms in soft tissue — specifically skeletal muscle tissue or sometimes in hollow organs such as the bladder or uterus. RMS can occur at any age, but it most often affects children.
- Solitary Fibrous Tumour: Solitary fibrous tumours are rare growths of soft tissue cells that can form nearly anywhere in the body. Solitary fibrous tumours most often occur in the lining around the outside of the lungs (pleural solitary fibrous tumours). Solitary fibrous tumours have also been found in the head and neck, breast, kidney, prostate, spinal cord, and other sites.
- Synovial Sarcoma: Synovial sarcoma is a rare type of cancer that tends to arise near large joints, particularly the knee, in young adults. Despite its name, it typically doesn’t affect the interior of joints, where synovial tissue and fluid are located.
- Undifferentiated Pleomorphic Sarcoma: It was formerly referred to as malignant fibrous histiocytoma, is a type of soft tissue cancer. The word “undifferentiated” in undifferentiated pleomorphic sarcoma means that the cells don’t resemble 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.
Most of the sarcomas begin in an arm or a leg. The common symptoms noticed at first is a lump that usually grows over a period of time. This lump is generally not painful, but in some cases it could be. There are times when the lumps may not be noticeable until they’re big enough to press on nearby muscles or nerves. About one in five soft tissue sarcomas happen in the belly. People usually don’t learn that they have one until they cause other problems, such as stomach ache, bleeding, or a blocked intestine. A doctor might find a sarcoma in your lungs or chest only after you have chest pain or trouble breathing.
About 10% of the time, a sarcoma will start in the head and neck region. The most common type of soft tissue sarcoma in children, called rhabdomyosarcoma, happens mostly in those areas.
One should consult the doctor if:
- They notice a growing lump somewhere on your body.
- They have stomach pain that’s getting worse.
- The stool appears black or bloody.
- They are vomiting blood.
Most visible lumps aren’t sarcoma. They’re usually a harmless cluster of fat cells called a lipoma. But if there is one that’s bigger than 2 inches and growing or causing pain, a doctor needs to be consulted.
Though most cancers are caused due to mutations in the DNA, Doctors aren’t sure why these types of cancers happen. However, some things may raise the chances of having soft tissue sarcoma:
- A family history of certain diseases that you can inherit from your parents. These include neurofibromatosis and Gardner syndrome, which are disorders that make tumours grow in parts of your body.
- Certain chemicals like arsenic, vinyl chloride, or dioxin.
- Radiation, including ones taken during the treatment of other types of cancer
Since there are different types of soft tissue sarcoma, it is crucial to determine the exact type so that effective treatment can be administered. The multiple ways, the combination of which can be used for accurate diagnosis are:
- Imaging tests:
- Computerized tomography scans
- Magnetic resonance imaging
- Positron emission tomography
- Biopsy: Biopsy is the process where a part of the affected tissue is extracted and examined under a microscope. Experienced doctors will select the best biopsy technique to ensure proper surgical treatment and planning such as:
- Core needle biopsy. Tiny tubes of tumour material can be obtained by this method. Doctors typically try to take samples from several sections of the tumour.
- Surgical biopsy. In some cases, your doctor might suggest surgery to obtain a larger sample of tissue or to simply remove a small tumour entirely.
Surgery is often the main treatment for soft tissue sarcoma. Surgery involves removing the cancer and some surrounding healthy tissue along with it. Radiation and chemotherapy is also administered in combination depending on the treatment plan.
- Radiation Therapy: Radiation therapy involves treating cancer with high-powered beams of energy. Radiation therapy can be administered:
- Before surgery: Also called neo-adjuvant radiation therapy, it can help shrink the tumour so that it’s easier to remove.
- During surgery: Intraoperative radiation allows a higher dose of radiation to be delivered directly to the target area, while sparing surrounding tissues.
- After surgery: Also called adjuvant radiation therapy, it helps kill any remaining cancer cells.
- Chemotherapy: Chemotherapy is a drug treatment that uses chemicals to kill cancer cells. Chemotherapy can be administered by pill or through a vein (intravenously). Some forms of soft tissue sarcoma respond better to chemotherapy than do others. For instance, chemotherapy is often used to treat rhabdomyosarcoma.
- Targeted drug treatment: Certain types of soft tissue sarcoma have specific characteristics in their cells that can be attacked via targeted drug treatments. These medicines work better than chemotherapy and aren’t nearly as toxic. Targeted treatments have been particularly helpful in gastrointestinal stromal tumours (GISTs).