Prophylactic central nervous system therapy in childhood acute lymphatic leukemia. Effect of poor-risk patients on the results.

The results of treatment in a group of 50 children with acute lymphatic leukemia are summarized. A comparison was made between those who received prophylactic central nervous systen (CNS) therapy on attaining complete remission and those who did not. Although none of the prophylactically treated children developed CNS leukemia, the expected prolongation of median complete remission time was not achieved. It was found that there was a high percentage of poor-risk patients in the CNS-treated group, and these patients relapsed early in the course of the disease. The prevention of CNS leukemia, a late complication of the disease, did not change the natural course of the disease in poor-risk patients. A need exists for new treatment protocols aimed at better control of the disease in these poor-risk cases.