[Treatment of high and low risk acute lymphoblastic leukemias in the child, with 2 modalities of preventive therapy on the central nervous system (Pethema 7/78 protocol)].

More effective therapy of high-risk patients and less toxic CNS prophylaxis are two goals in present acute lymphoblastic leukemia treatment research. Protocol LA A 7/78 was based on: 1) Distribution of patients in 2 therapy groups: standard (SR) and high-risk (HR) according to presence of clinical and hematological prognostic factors. 2) Remission induction in SR with PRED, VCR and ASPAR, and as maintenance, combination of MP and MTX. HR patients were given 4 drugs, with addition of DAUNO; reinductions with PRED, VCR and DAUNO every 3 months were given as well. 3) CNS prophylaxis in both groups was given according two modalities, on a randomized base. "A": cranial irradiation (24Gy) plus i.t. MTX, 6 doses. "B": i.t. MTX and ARA-C, 10 doses (6 weekly and 4 monthly). From 1978 to 1983, 76 patients under 14 years old were entered in study: 22 in HR and 54 in SR groups. All attained remission. After a median follow-up of 49 months estimated disease-free survival rate is 65.6% corresponding to 70% in SR and 56% in HR. Modality "B" of SNC prophylaxis (without irradiation) was, at least, as effective as modality "A" in SR and HR groups; estimated disease free survival is 60.5% +/- 9% in "A" and 71 +/- 8.5% in "B" therapy. Mortality by infections in patients in remission was less than 4%. This low proportion can be attributed in part to continuous use of cotromoxazol. Main conclusions of this study are: 1. Need for more intensive induction and consolidation therapy, especially in high-risk patients, and 2. That prolonged (5 months) intrathecal chemotherapy can substitute cranial irradiation in CNS prophylaxis.