Soft Tissue Sarcomas: Are the Causes Biological or Environmental?

Soft-tissue sarcomas (STS) are tumors that develop from two types of immature cells: mesenchymal and nerve cells. Normally, these two cells eventually form into the organs of the body, the blood cells, nerve endings, and muscle fibers. When the nerve and mesenchymal cells mutate, they become cancerous tumors, comprised of aggressive cells that multiply out of control.

Doctors have no real explanation for the reason why some people develop sarcomas. They think certain aspects increase the risk of patients, including previous injury, environmental exposure, and biological factors.

Past injury to an area has been shown to have a connection to the formation of sarcomas. Injuries can include scar tissue, bone fractures, previous radiation treatments, and serious burns.

Exposure to certain carcinogens -- especially vinyl chloride, polycyclic hydrocarbons, asbestos, and possibly marijuana and cocaine -- have been linked to increased incidences of sarcomas. Certain samplings of factory workers were at a higher risk for developing, or having developed, sarcomas.

The highest incidences of sarcomas seemed to be linked to biological factors, in particular, genetic disorders such as Li-Fraumeni Syndrome (a rare family predisposition to multiple cancers), and Neurofibromatosis, Type I (an inherited disorder characterized by formation of tumors involving nerve tissue in the skin, subcutaneous tissue, cranial nerves, and spinal root nerves). A compromised immune system from HIV, Lupus, congenital defects, and certain medications also contribute to the formation of sarcomas.

There is no known prevention for STS. Industrial workers should follow all safety guidelines, and anyone at risk from biological factors must have frequent screenings and immediately report any new lumps. One should minimize exposure to possible environmental factors as much as possible.

Doctors have identified more than fifty types of sarcomas. Each type of sarcoma is named for the type of cells it most resembles. These include Liposarcoma (fat cells), Fibrosarcoma (connecting tissue cells), Synovial Sarcoma (lining of joints), Neurofibrosarcoma (nerve tissue), Leiomyosarcoma (smooth muscle cells), Rhabdomyosarcoma (cells that become skeletal muscles), and Angiosarcoma (blood cells).

The symptoms of sarcomas begin painlessly, usually with the patient discovering a mysterious lump, most commonly in the extremities, or the trunk; less commonly in the head. The lump is generally insensate, and may be dismissed as a sports injury, scar tissue from shaving with a razor, or a skin tag for months or even years, until it grows to such a large size as to rule out many of the aforementioned explanations.

All types of cancers are given a stage classification, from Stage I to Stave IV-B, and Recurrent:

Stage I: Cancer cells are well differentiated, and the tumor is generally less than five centimeters (Stage I-A), or greater than five centimeters (Stage I-B), with no spread to the lymphatic system or other regions of the body. In this stage, tumors are unlikely to metastasize. Surgery is always performed, unless the tumor is inoperable, and followed up by radiation. Five-year survival rates are 80%.

Stage II: Cells are not as clearly differentiated. The tumor may be of any size, but has not spread to lymph nodes or distant parts of the body. Surgery is performed whenever possible, coupled with pre-operative radiation to shrink tumors, and followed by postoperative radiation. Chemotherapy may be used to prevent re-occurrences of tumors. Five-year survival rates are 70%.

Stage III: The cells are barely differentiated, or not at all, but tumors have not spread throughout the lymphatic system or to other regions of the body. The treatment is the same for Stage II tumors, and the five-year survival rate is 50%.

Stage IV-A: The cells have rapidly multiplied and infected lymph nodes, but have not spread to other areas of the body. Surgery is used to remove the cancerous tissue, including the lymph nodes, and paired with radiation. There is no conclusive data that chemotherapy is beneficial for treatment of Stage III, IV-A, or IV-B tumors. Five-year survival rate is 10% for Stage IV-A.

Stage IV-B: The cancerous cells have spread throughout the body, invading multiple organs, including the brain, lungs, and kidneys. Chemotherapy is used to relieve symptoms, and many patients may opt to enter holistic therapy, or volunteer for new and experimental drugs. In the cases of lung involvement, small patches may be removed to halt the progress. Stage IV-B has no five-year survival statistics available.

Recurrent: Generally, the tumors reappear at the original sight of exposure, but rarely appear in other areas of the body. Treatment depends on previous measures, and the current stage of the recurrent tumor. 80% of all recurrent tumors reappear within two years.

More and more, orthopedic oncologists are doing limb-sparing surgery, avoiding the radical amputations of the past in favor of a more moderate, just-as-effective approach. Surgeries are always followed up with radiation, with the exception of Stage IV-B STS. While several types of radiation therapy are approved for treatment of sarcomas, the two most common types are external beam radiation and brachytherapy.

In external beam radiation, a beam targets the cancerous tumor from the outside. The treated area may appear sunburned. In brachytherapy, small pellets of radioactive material are placed directly into the tumor, killing the cells. These pellets are removed before a patient is discharged. Generally, brachytherapy is only performed in a hospital, under the constant supervision of medical staff.

Chemotherapy is a controversial treatment for sarcomas. No clear data exists in regards to its benefits. Because chemotherapy uses anti-cancer drugs -- taken orally or injected -- that kill healthy tissue as well as cancer cells and cause nausea, vomiting, loss of appetite, hair loss, anemia, bleeding, tiredness, and decreased immunity, it is often disregarded as part of a treatment plan.

Some sarcomas are relatively common, especially in children. Good treatment parameters have been established, and patients go on to have a full life, with only the minor inconvenience of regular checkups. Other STSs are rarer, including Synovial Sarcoma and Angiosarcoma. Because of the low occurrences of these types of sarcomas, they are not as extensively researched, making them more challenging to overcome. As with any illness, keeping a positive attitude, educating oneself, and having a trusting rapport with one's treatment team is essential to survival.

Author Unknown, "ACS: What is a Soft-tissue Sarcoma?".Cancer.org. URL: http://www.cancer.org/docroot/CRI/content/CRI_2_4_1X_What_is_sarcoma_38.asp

Author Unknown, "Soft Tissue Sarcomas: Questions and Answers". Cancer.gov. URL: http://www.cancer.gov/cancertopics/factsheet/sites-types/soft-tissue-sarcoma

Author Unknown, "What Is Sarcoma?" Sarcoma.net. URL: http://sarcoma.net/facts.htm