Lower doses of chemo just as effective in childhood cancers

May 17 2005

In the latest research into treating a common childhood cancer, paediatric oncologist Allen Chauvenet, is optimistic that the long-term side effects that survivors experience as they grow into adulthood can be reduced.

Chauvenet and his colleagues at Brenner Children's Hospital, hopes this latest research into treating a common childhood cancer will reduce the number of long-term side effects that survivors experience as they grow into adulthood.

Chauvenet and his colleagues looked at the current chemotherapy prescribed for Acute Lymphblastic Leukaemia (ALL), the most common childhood cancer diagnosed in the United States, and found that though the cure rates for this cancer have dramatically improved over the years, many children have considerable long-term side effects, such as significant drops in IQ scores, growth failure and infertility. Chauvenet wanted to identify patients whose cancer could be cured, while minimizing the long-term effects of the treatment.

Relatively limited amounts of chemotherapy were used for children identified as having an excellent chance of cure and Chauvenet and his team monitored the group of 650 patients for about 12 years.

They discovered at the end of the study, that 86.4 percent of patients were described as event-free survivors at the end of 10 years. And 95.9 percent were overall survivors at the end of the 10-year period. Event-free survivors were patients who had no relapses or second malignancies in the time frame. Overall survivors experienced one of those conditions, but were still living at the end of the study period.

Chauvenet says this demonstrates that using limited chemotherapy worked in a large number of cases with minimal complications, and the next step would be to ' fine-tune the identification of those patients upfront' in order that long-term side effects are avoided in as many patients as possible.

Chauvenet and his colleagues looked for factors that might predict which children would do well with less intensive chemotherapy drugs, such as gender, race, white blood cell counts, whether the patient had an extra copy of certain chromosomes, and they also looked at the patient's bone marrow count two weeks into diagnosis.

They found that bone marrow count and extra chromosomes were the only two factors that played into whether the patients would have a reoccurrence or not do so well with lower doses of their chemotherapy regime.

He says this means that those can be looked for in the initial diagnosis and taken into consideration when treatment plans are being developed, and possibly a slightly more intensive therapy be added to the treatment of patients with these particular factors to improve their outcomes.

ALL is the most common malignancy in children. About 3,500 children are diagnosed each year with this disease. Most have about an 80 percent chance of overall survival after eight years. Brenner Children's Hospital, part of Wake Forest University Baptist Medical Center, sees an average of 20 new patients each year affected with ALL.

The study was presented at the American Society of Paediatric Haematology/Oncology (ASPHO) annual meeting in Washington, D.C.