New hope for rare brain cancer
PCC’s new study shows efficacy of combination chemotherapy on children.
A new study by Parkway Cancer Centre (PCC) offers hope to children who suffer from a rare form of brain cancer called germinoma. It has found combination chemotherapy to be effective in children with intracranial germinoma, which often occurs at the deepest part of the brain, making it highly risky to remove the tumour by surgery.
According to Dr Anselm Lee, a paediatrician with a special interest in paediatric haematology and oncology at PCC, the usual approach to treating malignant brain tumours in both children and adults is to remove as much of the tumour as possible. The patient is then given radiation treatment and, if needed, chemotherapy. “But when a germinoma is suspected, surgical treatment is not always successful,” he says.
Indeed, a study from Istanbul, recently published in the Turkish Neurosurgery journal, showed that when surgery was performed first on five patients with primary intracranial germinoma, four had successful outcomes, but the fifth, a 12-year-old boy, died from surgical complications.
PCC, however, has found that out of 10 children who were 18 years old or younger and who had received treatment based on chemotherapy and radiotherapy, with a median follow-up of over six years, all are still surviving and cancer-free. These findings have been published ahead of print in the same medical journal.
“Germinoma does not occur randomly inside the brain,” Dr Lee, the lead author, notes in the study. “Most of them are found near the pituitary gland or the pineal gland. In some cases, a small amount of tumour marker can be detected in the blood or from the cerebrospinal fluid, the clear liquid that circulates in the central nervous system. The rich blood supply to the cancer also gives them a characteristic appearance on magnetic resonance imaging (MRI).”
When a patient is suspected to have germinoma, doctors typically recommend confirming it by a biopsy rather than removing the tumour completely by surgery. In some cases, the MRI finding and positive tumour marker can be used for diagnosis, sparing children the biopsy procedure.
“It is heartbreaking to see a child dying from the complications of treatment,” says Dr Lee. “When germinoma is suspected, heroic attempts to remove the tumour should be avoided.”
PCC’s study indicates that combination chemotherapy has been found to be highly effective in children with intracranial germinoma. In half of the cases, the tumour was no longer visible on the MRI after just two cycles of treatment.
At PCC, children with primary intracranial germinoma are treated with four cycles of chemotherapy combining carboplatin and etoposide. They also receive radiotherapy to the cranium.
“Instead of radiating the whole brain, our radiation oncologists are using periventricular therapy with a booster to the primary tumour,” says Dr Lee. This form of treatment reduces the exposure of a large volume of normal brain tissue in the cortex to radiation, thus lessening the potential side effects on a growing child.
Parents may ask if their children can tolerate the chemotherapy. PCC’s study showed that the 10 children treated had received the combination of carboplatin and etoposide well.
Of the 10 children, seven had diabetes insipidus as a result of germinoma. This type of water diabetes, which differs from the more common sugar diabetes that needs insulin treatment, can be dangerous if the patient receives a lot of fluid for replacement or hydration. Dr Lee’s regimen, however, did not require fluid therapy, so none of the children with water diabetes had problem with water balance during treatment. The children did not even have to stay in hospital.
“When I started to treat children with cancer 27 years ago, I realised how miserable it was when children with primary intracranial germinoma were receiving treatment in the hospital,” says Dr Lee. “We decided to search for a better way of treatment and eventually came to this combination treatment.”
Feedback from neurosurgeons, radiation oncologists and endocrinologists has shown that this innovative approach to treating germinoma is effective. “But it is the patients on long-term follow-up,” adds Dr Lee, “who testify to the efficacy of our treatment.”
Tags: brain cancer, chemotherapy, rare cancer, tumour markers, tumours