News Note: New chemotherapy scheduling improves survival for most common form of childhood leukemia
New NCI-sponsored clinical trial results reported today at the annual American Society of Clinical Oncology meeting in Chicago show that, in a high-risk form of pediatric acute lymphoblastic leukemia (ALL), a high-dose schedule of a drug raises already high cure rates even higher. ALL, a fast-growing cancer of the white blood cells, is the most common cancer in children. About 2,500 children are diagnosed with ALL in the U.S. each year, with about one-third having the high-risk form. Currently, cure rates exceed 75 percent for children with high-risk ALL, compared to 90 percent or greater for children with standard-risk ALL. Over a period of seven years, this Children’s Oncology Group study of nearly 2,500 adolescents and young adult patients, ages 1 to 30, tested the safety and efficacy of new delivery schedules of established drugs to increase the rate of survival free from relapse.
Study investigators found that the five-year event-free survival for patients who received high-dose methotrexate, a drug that acts by inhibiting the metabolism of folic acid, was 82 percent, compared to 75 percent for patients on an escalating standard-dose methotrexate regimen. There were fewer bone marrow and central nervous system relapses in the high-dose methotrexate group. High-dose methotrexate was also well tolerated by patients and there was no evidence of increased toxicity. Methotrexate has been an essential component in the treatment of children with ALL for more than 50 years, but the optimal dose and schedule has been a matter of debate and clinical research. This trial offers a definitive answer to the dosing schedule question for children with high-risk ALL and provides a standard to use in the future.