Rhabdomyosarcoma is a type of sarcoma, or cancer, of the muscles and accounts for approximately five percent of all childhood cancers, and more than half of the soft tissue sarcomas diagnosed in children. It can appear anywhere in the body, but most commonly originates in the head and neck region; extremities (arms, elbows, legs, knees, thighs, feet, or shoulders); trunk (abdominal wall, breast or chest wall); orbit (bones of the eye socket or optic nerves); pelvis; and gastrointestinal tract. The disease can occur at anytime throughout childhood, but is most commonly diagnosed in children under age six.
There is a slightly higher incidence of rhabdomyosarcoma among boys. In addition, a higher incidence of the disease occurs among children exposed to chemicals and chemical pollution and whose fathers are cigarette smokers.
Rhabdomyosarcoma is one of the cancers that occurs in families with a cancer-related syndrome called Li-Fraumeni syndrome. However, most families of patients with rhabdomyosarcoma do not appear to be affected by the syndrome.
Symptoms usually occur when the tumor presses upon and interferes with the function of surrounding tissues or organs. For example, a head and neck rhabdomyosarcoma might affect hearing on the affected side.
Rhabdomyosarcoma Diagnostic Tests
If rhabdomyosarcoma is suspected, the physician may perform a biopsy, the removal of a small piece of tissue to be studied under a microscope for the presence of cancer cells. Other tests that may be used include: a CT (computerized tomography) scan of the chest, abdomen, and pelvis to check for any spread of the disease; ultrasound; an MRI (magnetic resonance imaging) scan to show the exact position of the tumor and whether it has spread; and blood and bone marrow tests, which show whether the cancer has spread to these areas.
Upon diagnosis, rhabdomyosarcomas are typically classified into four types:
- embryonal: The most common type, most frequently seen in head and neck and genitounrinary tumors.
- botryoid: A variation of the embryonal type that most frequently arises as polyps, or, grape-like lesions in the genitourinary tract.
- alveolar: This more aggressive form of the disease is most often found in the extremities or trunk.
- pleomorphic: This rarest form of the disease typically occurs in the extremities or trunk.
Treatment for rhabdomyosarcoma includes chemotherapy, the use of anitcancer drugs. After reduction of the original tumor with chemotherapy, surgery, or radiation therapy, the use of targeted X-rays to kill cancer cells, will be performed to treat local sites of the disease.
Overall, more than 60 percent of patients diagnosed with rhabdomyosarcoma enjoy long-term survival using these combine therapies. For patients diagnosed with early-stage tumors, the cure rate rises to 80 percent or higher.
Current research efforts are directed at identifying more effective drug combinations and therapies.