What is a malignant rhabdoid tumor?
A malignant rhabdoid tumor is a rare childhood tumor that commonly starts in the kidneys but also can occur in other soft tissues or in the brain, where it is referred to as atypical teratoid rhabdoid tumor (ATRT). These tumors occur most commonly in infants and toddlers. The average age of diagnosis is 15 months old. There are about 20 to 25 new cases of malignant rhabdoid tumor diagnosed each year in the U.S. Cells from malignant rhabdoid tumors in children can spread to other areas of the body.
How we care for malignant rhabdoid tumors
At Dana-Farber/Boston Children's Cancer and Blood Disorders Center, we treat children with a malignant rhabdoid tumor through our Solid Tumor Center, a world-leading center in the research and treatment of rhabdoid tumors. Our vibrant program of basic and translational research into rhabdoid tumors is uncovering new opportunities to improve the care of children with this diagnosis. Our multidisciplinary treatment approach ensures in-depth discussion of each child and personalized treatment plans for every patient.
Our areas of research for malignant rhabdoid tumor
Researchers at Dana-Farber/Boston Children's are global leaders in the basic and translational study of rhabdoid tumors. Their goal is to understand the biological basis of rhabdoid tumors, including the role(s) of mutations in the gene SMARCB1, and to develop more effective treatment methods for children with these tumors.
In addition, we have a phase I clinical trial open for children with refractory or relapsed malignant rhabdoid tumor, as well as access to any malignant rhabdoid tumor trials available through the Children's Oncology Group.
For many children with rare or hard-to-treat conditions, clinical trials provide new options.
Malignant Rhabdoid Tumor | Symptoms & Causes
What are the symptoms of a malignant rhabdoid tumor?
Often the first sign that a child has a malignant rhabdoid tumor is the discovery of a lump or mass in the child's abdomen. Because these tumors occur most frequently in infants, the child may not show any signs of pain or discomfort beyond fussiness, potentially making early diagnosis difficult. Some children with malignant rhabdoid tumor may have difficulty urinating or blood in the urine.
What causes a malignant rhabdoid tumor?
There is no clear cause of a malignant rhabdoid tumor. Researchers have discovered that a gene called SMARCB1 (this gene also goes by the names INI1, SNF5, and BAF47) is mutated in nearly all rhabdoid tumors, including malignant rhabdoid tumors. Mutations in this gene can also sometimes occur in a patient’s normal, non-tumor cells, increasing their risk of developing additional rhabdoid tumors.
Malignant Rhabdoid Tumor | Diagnosis & Treatments
How are malignant rhabdoid tumors diagnosed?
Diagnostic procedures for a malignant rhabdoid tumor are used to determine the exact type of tumor your child has and whether or not the tumor has spread. Your child’s doctor will perform a complete medical and physical examination.
Your child’s physician may also order some of the following diagnostic tests:
- biopsy or tissue sample
- computerized tomography scan (CT or CAT scan)
If a biopsy is taken, the sample will be tested for mutations in a gene called SMARCB1 (this gene also goes by the names INI1, SNF5, and BAF47), which is turned off in nearly all rhabdoid tumors.
If a mutation is found, your child's doctor may recommend additional tests.
What are the treatment options for a malignant rhabdoid tumor?
Treatment involves a combination of therapies including surgery, radiation, and chemotherapy. However, because this tumor is rare and aggressive, there is no defined standard of care, and treatment options may be tailored to your child's situation. Your child's doctor and other members of your care team will discuss the options with you in depth. Prompt medical attention and aggressive therapy are important for the best prognosis.
In most cases, the first step in treating malignant rhabdoid tumor is surgery. Often a surgeon will try to remove the whole tumor at the time of biopsy. Depending on the size and location of the tumor, the surgeon may remove only part of the kidney or the whole kidney.
After surgery, children with a malignant rhabdoid tumor are treated with a very aggressive course of chemotherapy, a group of drugs that interfere with the cancer cell’s ability to grow or reproduce. Different groups of chemotherapy drugs work in varied ways to fight cancer cells and shrink tumors. Often, a combination of chemotherapy drugs is used. Certain chemotherapy drugs may be given in a specific order depending on the type of cancer it is being used to treat.
Children who are more than six months old also may receive radiation therapy as part of their treatment.
Stem cell transplantation
The treatment of a malignant rhabdoid tumor can be so intense as to affect the body's ability to produce normal blood and immune cells. For that reason, your child's doctor may recommend that your child undergo a stem cell transplant. This involves temporarily removing some of a child’s healthy blood cells and giving her very high doses of chemotherapy and, in some cases, radiation therapy to overwhelm and destroy the malignant rhabdoid tumor. The child is then given back their own stored healthy blood cells to promote normal body and organ function once treatment is done.
Supportive care is treatment to prevent and treat infections, side effects of treatments, and complications. The goal is to keep your child comfortable during treatment. It also is an important part of preventing short and long-term complications of the disease and treatment.
What is the long-term outlook for children with a malignant rhabdoid tumor?
Your child’s chance of recovery and treatment options depend on a number of different factors:
- extent of the disease
- size and location of the tumor
- tumor's characteristics when examined under a microscope
- presence or absence of metastasis
- tumor's response to therapy
- age and overall health
- your child's tolerance of specific medications, procedures, or therapies
- new developments in treatment
In general, malignant rhabdoid tumors are very aggressive and difficult to treat. Patients often initially respond well to treatment, but relapse either during or shortly after treatment remains a risk. Children with germline mutations to SMARCB1 also have a high risk of developing second tumors. Prompt medical attention and appropriate therapy are important for the best prognosis.