[Maintenance chemotherapy and inmunotherapy in acute lymphoblastic leukemia (author's transl)]

Sixty-one children with ALL were treated between 1970 an 1973 according to a scheme including: a) Remission induction with vincristine-prednisolone-daunorubicine. b) Cytoreduction therapy with 4 drugs (6-MP, MTX,Ara-C and CYCLO) combined two by two in 3 types of associations given at three months cycles. Every three months, two-week "reinductions" with vincristine and prednisolone plus one dose of i.t. MTX. c) Early therapy on CNS, according to two patterns: one group received one dose of i.t. MTX after induction, repeated every 3 months; the other group was given cranial irradiation [2,400 r] plus 5 doses of i.t. MTX. d) After three years of chemotherapy, patients were treated for two more years with BCG by scarification.

Complete remission was achieved in 93%. After three years of chemotherapy, 37% of the first group (not irradiated) and 55% of the second (irradiated) persisted in C.R. Twenty-five patients initiated BCG-therapy; eighteen of these (72%) persisted, after 2 years, in C.R.; then all treatment was suppressed. Initial relapses in the 5 years period were hematological in 13, CNS in 13, both hematological and CNS in 2, and testicular in 3. Mortality of patients in C.R. was 4 (7.7%). Survival rates were 33% after 5 years for the non-irradiated group and 50% in the irradiated one. At present, 30% of all evaluable patients who attained remission continue in C.R. after an average time of 102 months-40% in the irradiated group and 20% in the not irradiated-. This difference, statistically significant, is due to the number of CNS relapses: 13 of 30 (43%) in the first group and 3 of 22 (13.1%) in the second. The 24% relapses occurring during immunotherapy do not permit to assess the efficacy of this form of therapy.