Rhabdomyosarcoma is a childhood cancer. It begins in cells that will become skeletal muscle cells. Skeletal muscle is attached to bones and is different from the smooth muscle that lines the intestinal tract (esophagus, stomach, small and large intestines). With rhabdomyosarcoma, these muscle cells grow uncontrollably and form masses or lumps called tumors. They can start almost anywhere in the body where there is skeletal muscle.
Description
Rhabdomyosarcomas can start in any organ that contains skeletal muscle cells, but most commonly tumors are found in the head and neck and in the prostate, bladder, and vagina. From 5-8% of all cancers diagnosed in children are rhabdomyosarcomas.
Demographics
Rhabdomyosarcoma occurs most frequently in children ages 2 to 6 and 15 to 19 years old. More males than females develop rhabdomyosarcomas. Among younger children, the tumor is usually in the head and neck and may involve the area surrounding the eye. Less often, young children develop rhabdomyosarcomas of the genitourinary tract (bladder, prostate, vagina).
In the older age group, the most likely site is the male genitourinary tract, especially the testes and surrounding area. Other body parts where rhabdomyosarcoma may begin are on the arms, legs, trunk, or deep inside the abdomen (retroperitoneum).
Some cases of rhabdomyosarcoma run in families and are linked to genetic syndromes. Immediate family members of children with rhabdomyosarcoma are at increased risk of developing certain cancers that are not rhabdomyosarcomas, such as breast and brain tumors.
The symptoms of rhabdomyosarcoma depend on the site of the tumor and whether it has spread. When rhabdomyosarcoma begins in the head, it may involve the area surrounding the eye, the nasal passages or the ear and throat. Tumors in these areas may cause swelling,
especially around the eye; blocked nasal passages or sinuses; ear pain and bleeding; and difficulties swallowing. Rhabdomyosarcomas in the head and neck may also put pressure on the brain or nerves.
When rhabdomyosarcoma affects an arm, leg or other body part, the swelling may be mistaken for a bruise or other injury. When the genitals or urinary tract are involved, there may be symptoms such as recurring urinary tract infections, blood in the urine, incontinence, or blockage of the urinary tract or rectum.
Rhabdomyosarcoma affecting the testes may cause swelling of the scrotum. When the uterus or vagina is affected, there may be a mass or small tumor pushing into the vaginal canal.
Diagnosis
Some patients who have rhabdomyosarcomas go to the doctor because they have discovered a lump or mass or swelling on a body part. Others have symptoms related to the part of the body that is affected by the tumor. The patient's doctor will take a detailed medical history to find out about the symptoms. The history is followed by a complete physical examination with special attention to the suspicious symptom or body part.
A biopsy of the tumor is necessary to make the diagnosis of rhabdomyosarcoma. During a biopsy, some tissue from the tumor is removed. The tissue sample is examined by a pathologist, a doctor who specializes in the study of diseased tissue.
Types of biopsy
The type of biopsy done depends on the location of the tumor. For some small tumors, such as those on the arm or leg, the doctor may perform an excisional biopsy, removing the entire tumor and a margin of surrounding normal tissue. Most often, the doctor will perform an incisional biopsy, a procedure that involves cutting out only a piece of the tumor. This biopsy provides a core of tissue from the tumor that is used to determine its type and grade.
Treatment team
Patients with rhabdomyosarcoma are usually cared for by a multidisciplinary team of health professionals.
The patient's pediatrician, or primary care doctor may refer the patient to other physician specialists, such as surgeons and oncologists (doctors who specialize in cancer medicine). Radiologic technicians perform x ray, CT and MRI scans and nurses and laboratory technicians may obtain samples of blood, urine and other laboratory tests.
Before and after any surgical procedures, specially trained nurses may explain the procedures and help to prepare patients and families. Depending on the tumor location and treatment plan, patients may also benefit from rehabilitation therapy with physical therapists and nutritional counseling from dieticians.
Clinical staging, treatments, and prognosis
Staging
The purpose of staging a tumor is to determine how far it has advanced. This is important because treatment varies depending on the stage. Stage is determined by the size of the tumor, whether the tumor has spread to nearby lymph nodes, and whether the tumor has spread elsewhere in the body.
Tumors are staged using numbers to designate Stages I through IV. The higher the number, the more the tumor has advanced. Stage I rhabdomyosarcomas have not extended beyond the site where they began; they are limited to a single muscle or organ. Stage II tumors show signs of spread beyond the muscle or organ where they began. Stage III rhabdomyosarcomas are tumors that could not be removed in their entirety by surgery. As a result, some tumor remains at the site where it began. Stage IV rhabdomyosarcomas have involved either lymph nodes or have spread to distant parts of the body.
Treatment
Treatment for rhabdomyosarcoma varies depending on the location of the tumor, its size and grade, and the extent of its spread. By the time most cases of rhabdomyosarcoma are diagnosed, there has already been some spread of the disease. For these patients, the goals of treatment are to remove or control the tumor and combat the spread of the cancer.
Generally, when completely removing the tumor will not sharply reduce function, rhabdomyosarcoma tumors are surgically removed. The site, size, and extent of the tumor determine the type of surgery performed. The goal of removing as much tumor as possible is to reduce the amount of radiation needed after surgery. The part of the body where the tumor was removed is treated with radiation to destroy remaining tumor cells. Many patients also receive chemotherapy.
When the disease has spread throughout the body, there may be no benefit from surgical removal of the tumor. These cases, usually patients with Group IV tumors, are treated with chemotherapy.
Side effects
The surgical treatment of rhabdomyosarcoma carries risks related to the surgical site, such as loss of function resulting from head and neck surgeries. Head and neck surgeries also may result in deformities that may be cosmetically unsatisfactory. There also are the medical risks associated with any surgical procedure, such as reactions to general anesthesia or infection after surgery.
The side effects of radiation therapy depend on the site being radiated. Radiation therapy can produce side effects such as fatigue, skin rashes, nausea, diarrhea, and secondary cancers. Most of the side effects lessen or disappear completely after the radiation therapy has been completed.
The side effects of chemotherapy vary depending on the medication, or combination of anticancer drugs, used. Nausea, vomiting, anemia, lower resistance to infection and hair loss are common side effects. Medication may be given to reduce the unpleasant side effects of chemotherapy.
Alternative and complementary therapies
Many patients explore alternative and complementary therapies to help to reduce the stress associated with illness, improve immune function and feel better. While there is no evidence that these therapies specifically combat disease, activities such as biofeedback, relaxation, therapeutic touch, massage therapy and guided imagery have been reported to enhance well-being.
Prognosis
The outlook for patients with rhabdomyosarcoma varies. It depends on the site of the tumor, how the cancer cells look under the microscope, and extent of spread. For example, patients with tumors affecting the area around the eye and the bladder are more likely to do well than patients with tumors that begin deep within the chest or abdomen.
Rhabdomyosarcoma may spread to areas near the tumor and it can spread to nearby lymph glands. To spread to distant parts of the body, the cells travel in the blood or through the lymph glands. The most common sites for metastasis (spread) are the lymph glands near the tumor, the lung, liver, bone marrow, and brain. In general, tumors that have spread widely throughout the body are not associated with favorable survival rates.
Patients with Stage I tumors that are completely removed surgically have excellent prognoses; eight-year survival is nearly 75%. Sixty five percent of patients with Stage II tumors are disease free after 8 years. Stage I and II rhabdomyosarcomas account for about 40% of all cases.
About 40% of patients with Stage III and 15% of those with Stage IV rhabdomyosarcomas are disease free after 8 years. Patients with tumors that do not respond to treatment and those who suffer recurrences have poor outlooks for long-term survival.
Coping with cancer treatment
Toddlers, children and teens undergoing cancer treatment have special needs. The diagnosis of a life-threatening illness, surgery and radiation or chemotherapy may cause fear, anxiety, depression and loss of self-esteem. Toddlers may be especially fearful when they are separated from their parents for medical tests and hospital stays. Disruption of their normal routines and discomfort from diagnostic tests and treatment may also cause anxiety. Older children face additional social problems including making up missed school work, explaining the illness and treatment to friends, and coping with physical limitations or disability.
Teens with serious illnesses and disabilities face special conflicts and challenges. One conflict is between the teen's growing desire for independence and the reality of dependence on others for the activities of daily living. It is important for teens to be fully informed about their disease and treatment plan and involved in treatment decision making. Many teens benefit from continuing contact with friends, classmates, teachers, and family during hospital stays and recovery at home.
Depression, emotional distress, and anxiety associated with the disease and its treatment may respond to counseling from a mental health professional. Play therapy often helps toddlers and young children to reveal and express their feelings about illness and treatment. Many cancer patients and their families find participation in mutual aid and group support programs help to relieve feelings of isolation and loneliness. By sharing problems with others who have lived through similar difficulties patients and families can exchange ideas and coping strategies.
Clinical trials
About 30 clinical studies were underway during 2001. For example, in one clinical trial at John Hopkins Oncology Center, patients with recurring or widespread rhabdomyosarcoma were being treated with chemotherapy to stop tumor cells from dividing and simultaneously being given stem cells (bone marrow transplantation) to replace the immune cells killed by chemotherapy.
Other clinical trials compare different combinations of chemotherapy drugs to find out which combination is most effective. For example, in one study, patients with previously untreated rhabdomyosarcoma were randomly assigned to two different combinations of chemotherapy drugs. Along with radiation therapy, patients in one group received three drugs, vincristine, dactinomycin, and cyclophosphamide once a week. Patients in the other group were given vincristine, cyclophosphamide, and topotecan, instead of dactinomycin.
Other types of clinical research study individuals and families at high risk of cancer to help identify cancer genes. To learn more about clinical trials visit the National Cancer Institute (NCI) CancerNet web site at http://cancernet.nci.nih.gov/ or the Pediatric Oncology Branch of the National Cancer Institute web site at http://www.dcs.nci.nih.gov/pedonc.
Prevention
Since the causes of rhabdomyosarcoma are not known, there are no recommendations about how to prevent its development. Among families with an inherited tendency to develop soft tissue sarcomas, careful monitoring may help to ensure early diagnosis and treatment of the disease.
Special concerns
Rhabdomyosarcoma, like other cancer diagnoses, may produce a range of emotional reactions in patients and families. Education, counseling and participation in group support programs can help to reduce feelings of guilt, fear, anxiety and hopelessness. For many parents suffering from spiritual distress, visits with clergy members and participation in organized prayer may offer comfort.
Resources
BOOKS
Murphy, Gerald P. et al. American Cancer Society Textbook of Clinical Oncology, Second Edition. Atlanta, GA: The American Cancer Society, Inc. 1995 pp.540-542.
Otto, Shirley E. Oncology Nursing. St. Louis, MO: Mosby, 1997 pp.397-401.
Pelletier, Kenneth R. The Best of Alternative Medicine. New York, NY: Simon & Schuster, 2000.
PERIODICALS
Arndt, Carola A. R., and William M. Crist. "Medical Progress: Common Musculoskeletal Tumors of Childhood and Ado lescence." New England Journal of Medicine. 29 July 1999; 341 (5):342-352.
ORGANIZATIONS
American Cancer Society. 1599 Clifton Road, N.E., Atlanta, GA 30329. (800)227-2345.
Cancer Research Institute. 681 Fifth Avenue, New York, NY 10022. (800)992-2623.
National Cancer Institute (National Institutes of Health). 9000Rockville Pike, Bethesda, MD 20892. (800)422-6237.
