DISEASE CHARACTERISTICS: Diagnosis of low-risk acute lymphocytic leukemia (ALL) (common ALL or pre-B-cell) Must meet 1 of the following 2 conditions: Age 51 to 65 and meets the following criteria: No mediastinal mass No T-cell or B-cell disease Age 15 to 50 and meets the following criteria: Philadelphia chromosome (Ph) negative bcr-abl negative Initial WBC less than 30,000/mm3 OR Diagnosis of T-cell ALL with or without mediastinal involvement Age 15 to 50 OR Diagnosis of high-risk ALL (common ALL or pre-B-cell) Age 15 to 50 and meets 1 of the following criteria: Ph positive bcr-abl positive Pre-pre-B-cell disease, i.e., t(4;11) Initial WBC greater than 30,000/mm3 OR Diagnosis of B-cell ALL

PATIENT CHARACTERISTICS: Age: See Disease Characteristics 15 to 65 Performance status: Not specified Life expectancy: Not specified Hematopoietic: See Disease Characteristics Hepatic: Not specified Renal: No renal failure Cardiovascular: No cardiomyopathy Other: HIV-1 and HIV-2 negative No severe psychiatric disease

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior cytostatic drugs except vincristine Endocrine therapy: Prior corticosteroids allowed Radiotherapy: Not specified Surgery: Not specified Other: No more than 2 weeks of prior therapy No other prior cytostatic drugs