Rhabdoid tumours are treated with surgery followed by chemotherapy and sometimes radiation therapy.
How are rhabdoid tumours treated?
Surgery
Aggressive surgery is critical to survival. The ideal situation is to remove the entire tumour. However, it has been estimated that only one-third of children with rhabdoid tumour are able to have a complete removal of the tumour. This is because, often at the time of diagnosis, the tumour is too large or it has already invaded the cranial nerves in the cerebellopontine angle. In such cases, the goal is to remove as much of the tumour as possible. Sometimes, a second surgery can be done to remove more or the rest of the tumour.
Chemotherapy
After surgery, intensive intravenous treatment with chemotherapy is very important. Most children who survive a rhabdoid tumour have had intensive intravenous chemotherapy. There are various protocols that can be used for administering chemotherapy. Chemotherapy may involve the administration of various combinations of some or all of the following drugs: cyclophosphamide, cisplatin, etoposide, vincristine, carboplatin, and ifosfamide.
Some protocols call for the use of doxorubicin, which is a cancer drug that does not cross into the brain but may nonetheless have some effect on the treatment of rhabdoid tumour. The use of doxorubicin is controversial. When deciding whether to use doxorubicin, physicians need to consider not just the potential benefits but also possible side effects such as toxicity to the heart.
Chemotherapy may be given as high dose chemotherapy with or without intrathecal chemotherapy. Intrathecal chemotherapy is injected into the cerebrospinal fluid surrounding the brain and spinal cord. Intrathecal chemotherapy is recommended especially in children with residual/metastatic disease who will not receive radiation therapy.
The combination of high-dose chemotherapy with stem cell rescue is the subject of ongoing research.
Radiation therapy
Some protocols call for a combination of chemotherapy and radiation therapy after surgery. However, the role of radiation is not completely clear. The benefits of radiation need to be balanced against the potential harm it can cause to the developing brain. As a result, radiation has classically not been recommended for children under the age of three years. In older children, radiation appears to be most effective when used early in treatment.
There are two types of radiation that might be used: focal radiation or craniospinal radiation. Focal radiation is focused directly on the tumour. Craniospinal radiation is a type of radiation given to the skull and spine. The child may receive focal radiation alone, craniospinal radiation alone, or a combination of the two. It is not clear whether craniospinal radiation provides a real benefit in children with localized rhabdoid tumours.
Radiation may have some impact on survival, especially in older children. However, it is unclear whether the reason for improved survival with radiation in older children is the radiation itself or the older age of the child at diagnosis.
What is the outcome for a child with a rhabdoid tumour?
Rhabdoid tumours have always been considered highly malignant with a poor prognosis. The median survival time for children with this type of tumour is between six and 11 months.
However, recent studies have shown some better outcomes in children over the age of three years. Two years after diagnosis, most children over the age of three are still alive. This is especially the case if the children received both chemotherapy and radiation. There are some reports of long-term survivors.
Survival is greatest if the entire tumour can be removed, and also if intense chemotherapy is used. The role of radiation is unclear at this point.
If the disease is successfully treated and the tumour is removed, and there is no further recurrence after one year from treatment, the chance of the tumour returning is very low. If a child is still alive two years after treatment, his chances for long-term survival are very good.