Response to combination therapy after relapse in childhood acute lymphocytic leukemia

The objective of this study was to determine in children with acute lymphocytic leukemia (ALL) whether prolonged remission could be attained following relapse from prior chemotherapy. Multiple agent chemotherapy and central nervous system radiotherapy were administered to 16 children who had had one or more relapses. With prednisone, vincristine, and daunomycin, 14 of 16 patients attained complete remission in a median time of 31 days. The median duration of complete remission for the 14 children was 12 months. Drug toxicity and morbidity secondary to therapy included pancytopenia, oral ulcerations, nausea, vomiting, diarrhea, abdominal pain, and potentially fatal infections. Five of the 14 who achieved remission developed Pneumocystis carinii pneumonia. Patients who had relapsed during prior unmaintained remission had superior responses to therapy. After 46 to 50 months in this study, three patients remain in continuous complete remission and two others remain in continuous hematologic remission. Therapy was stopped in four children after 36 months of continuous hematologic remission. These results suggest that children with ALL who experience relapse have an opportunity for a prolonged subsequent remission.