Children with acute lymphoblastic leukemia (ALL) who are treated with effective, risk-adjusted chemotherapy regimens have good outcomes and may safely be able to avoid preventive radiation therapy to the brain. These results were published in the New England Journal of Medicine.
Acute lymphoblastic leukemia is cancer of the blood characterized by the rapid uncontrolled growth of abnormal, immature white blood cells known as lymphoblasts. Acute lymphoblastic leukemia is the most common leukemia in children, with approximately 3,000 new patients diagnosed each year in the United States.
Advances in the treatment of childhood ALL have dramatically improved survival rates. Cancer treatments can carry a risk of serious, long-term side effects, however, and researchers continue to seek ways to prevent or minimize these side effects without compromising treatment effectiveness.
Preventive radiation therapy to the brain is commonly used in the treatment of children with ALL who are thought to be at high risk of relapse in the brain. Radiation therapy to the brain can produce a range of late complications, however, including second cancers, cognitive difficulties, and hormonal problems.
To explore whether preventive radiation therapy to the brain can be safely omitted, researchers conducted a study among 498 patients, 71 of whom would have been candidates for radiation therapy to the brain by conventional standards. Patients were treated with intrathecal (into the cerebrospinal fluid) and systemic (whole-body) chemotherapy, with treatment intensity based on the risk features of each patient. Patients did not receive preventive radiation therapy to the brain.
- Five-year survival without disease relapse or progression was 86%.
- Overall five-year survival was 94%.
- The five-year risk of an isolated relapse in the central nervous system (brain or spinal cord) was 2.7%.
- Compared with a past group of patients who received radiation therapy to the brain, the 71 patients in this study who traditionally would have been candidates for radiation therapy had better cancer-free survival.
These results suggest that with appropriate, risk-adjusted chemotherapy, it may be possible to safely omit preventive radiation therapy to the brain in children with ALL. This would spare children from the long-term side effects of radiation to the brain.
Reference: Pui C-H, Campana D, Pei D et al. Treating childhood acute lymphoblastic leukemia without cranial irradiation. New England Journal of Medicine. 2009;360:2730-41.