Brain Cancer Responds to Chemotherapy
CancerWise - February 2009
Some children with the most common type of brain tumor may be treated with chemotherapy alone, avoiding radiation to the brain, which frequently causes side effects later in life.
A multi-institutional team that included scientists from M. D. Anderson presented results of this Phase III study last fall at the annual meeting of the International Society of Pediatric Oncology.
Significance of results
Low-grade glioma, the most common brain tumor in children, often is treatable by surgery. If their tumors can be removed surgically, more than 95% of children with gliomas survive.
However, if the tumors are located in areas of the brain that make surgery impossible, or if the tumor returns after surgery, the possibilities of a cure are much lower.
Cranial (to the head) radiation usually is used to treat low-grade gliomas. But while radiation frequently is effective, long-term side effects sometimes surface later in life.
Possible late side effects of cranial radiation include:
- Mental impairment
- Hormonal deficiencies
- Increased rate of stroke
Because of the high rate of side effects, some doctors and families decide against treating pediatric brain tumors with radiation.
If radiation can be postponed until a child is older, the possibility of side effects is often lessened.
Previous smaller studies have shown chemotherapy with carboplatin and vincristine (CV) is sometimes effective against low-grade glioma. But no other study has examined on such a large scale treating pediatric brain cancer with chemotherapy.
"This is the first large, multi-institutional study to investigate using chemotherapy as an alternative to cranial radiation," says Joann Ater, M.D., professor in the Division of Pediatrics at the Children's Cancer Hospital at M. D. Anderson. She is principal investigator on the Children's Oncology Group study and developed this trial.
This study enrolled 401 children from birth to age 10 with gliomas that could not be removed surgically.
Children without neurofibromatosis (an inherited disorder in which nerve tissue grows tumors) were assigned randomly to either treatment with CV or TPCV [thioguanine, procarbazine, CCNU (lomustine) and vincristine].
Patients with neurofibromatosis and progressive optic pathway gliomas were assigned to CV.
The TPCV regimen was more effective than the CV regimen. Almost half the patients had no disease progression for five years, and children 5 to 10 years old averaged more than eight years without disease progression.
On the CV regimen, average time before disease progression was more than:
- Two years in patients under 5 years old
- Five years in patients between 5 and 10 years old
Patients with neurofibromatosis and low-grade gliomas had the best response to chemotherapy among the three groups.
"The results of this study have confirmed the ability of chemotherapy to control this disease in some children," Ater says.
"If we can delay radiation, we allow more time for our youngest patients to develop physically, which could decrease some of the long-term effects from treatment," Ater says.
"This trial at least gives parents more information and alternative options when making decisions about their child's treatment."
— Adapted by Dawn Dorsey from and M. D. Anderson news release
M. D. Anderson resources:
- Childhood brain tumors
- Children’s Cancer Hospital