Soft-tissue sarcomas are types of cancers that develop in the soft tissues of the body such as the deeper layers of the skin, nerves, muscles, lymph or blood vessels. They are uncommon cancers and are most often found in a patient's arms or legs, though they can develop anywhere in the body.
Definition & Facts
Soft-tissue sarcomas develop from mesenchyme tissue, which are made up of loosely organized cells that can mature into blood, blood vessels, connective tissue, and other types of tissue. The sarcomas are named after the type of tissue they originated from or the type of tissue they resemble. For example, an angiosarcoma resembles a cell found in lymphatic tissue or blood vessels. There are many different types of soft-tissue sarcomas. They include:
- Epithelioid sarcoma - This type of sarcoma starts under the skin of the appendages, and most often affects teenagers or young adults.
- Desmoplastic small-round-cell tumor - This is a very rare sarcoma that also affects teenagers and young adults. Its most common site is the abdomen.
- Low-grade fibromyxoid sarcoma - This is a slow growing malignancy that’s often found in the arms, the legs, or the trunk. It mostly affects young to middle-aged adults. Its other name is Evans’ tumor.
- Low-grade myxofibrosarcoma- This type of soft-tissue sarcoma is found in the elderly. The sites are usually the arms or legs. The tumors are found just under the patient’s skin and may come in clusters.
- Synovial sarcoma - This tumor develops in the soft tissue that supports the joints. It’s most often found in children and young adults, but can also affect the elderly.
- Malignant peripheral nerve sheath tumors - This is a family of soft-tissue sarcomas that arise from the cells that enclose a nerve. Types of these sarcomas include malignant schwannomas and neurofibrosarcomas.
- Rhabdomyosarcoma - These are soft-cell sarcomas that begin in the skeletal muscles. The patients are often children.
- Gastrointestinal stromal tumor - These tumors are found in the GI tract, usually the small intestine or the stomach.
Symptoms & Complaints
The symptoms of angiosarcoma are varied, because this cancer can occur in many areas of the body. If it is in the breast, the symptoms include a thickening of the wall of the breast, a rash and discoloration of the skin of the breast, and a lump in the breast. If it’s found in the lung, the patient may experience chest pain, blood in sputum, cough, and difficulty breathing. If the sarcoma is found in other places, it can cause anemia, abnormal bleeding, weight loss, pain in the bones, and enlarged lymph nodes.
Malignant schwannomas are found in the nerves of the neck and the head. They don’t spread but they can grow large enough to press on areas of the brain and cause damage. In this case, symptoms are numbness in the face, a swelling on the patient’s face that can may or may not cause pain, ringing in the ear, and clumsiness.
The causes of most soft-tissue sarcomas are unknown, but there are risk factors. Some people inherit a predisposition to soft-tissue sarcomas. They inherit defective genes from their parents, such as the defect in the APC gene that causes a disease called Gardner's syndrome. This predisposes the patient to desmoid tumors, which are made from connective tissue and present as a mass. Desmoid tumors are extremely rare and don’t metastasize, but they can become so large that they interfere with the functioning of other organs. They usually develop in the abdomen.
Other risk factors for soft-tissue sarcomas are radiotherapy radiation used to treat other types of cancers, exposure to chemicals and a compromised lymphatic system. Smoking and many other lifestyle factors that cause many other cancers do not contribute to the onset of soft-tissue sarcomas.
Diagnosis & Tests
For many people, genetic testing is one way to let a patient know he or she is at risk for soft-tissue sarcoma. If it’s found that they have risk factors, they might pay more attention to any abnormal growths or lumps and have them examined by a doctor to find out whether or not they are soft-tissue sarcomas. As with other cancers, the earlier they are found, the more effectively they can be treated.
The doctor can also use several types of biopsies. With a fine-needle aspiration biopsy, the doctor inserts a needle attached to a syringe into the mass or lump and pulls out a small amount of tissue. A core needle is a larger needle that takes away a cylinder of tissue that’s about 1/2 inch long and 1/16 inch in diameter. This is a more effective way to diagnose a soft-tissue sarcoma than a fine-needle biopsy.
The physician can also remove a piece of the tumor during surgery and have it studied. The entire tumor can be taken out, which is an excisional biopsy. When only a piece of the tumor is removed, it is an incisional biopsy. The tissue is then tested to see if it is malignant. Tests determine the type and the grade of the sarcoma. The grade is also used to determine what stage the sarcoma is in. Sarcomas have three grades, which are 1 to 3.
Treatment & Therapy
Treatment and therapy for soft-tissue sarcomas include radiation, chemotherapy, surgery, or targeted therapy. Depending on the aggressiveness and the stage of the sarcoma, a combination of therapies can be used.
Prevention & Prophylaxis