PRIOR CONCURRENT THERAPY: No prior treatment for ALL Biologic therapy: Not specified Chemotherapy: Intrathecal cytarabine (IT ARA-C) may begin prior to registration provided systemic chemotherapy initiated within 72 hours after IT ARA-C Endocrine therapy: See Radiotherapy At least 1 month since prior systemic steroids Steroids given for less than 48 hours allowed Inhaled corticosteroids allowed at any time Radiotherapy: Radiotherapy or dexamethasone for mediastinal mass causing superior mediastinal syndrome allowed prior to registration, if indicated Surgery: Not specified