DISEASE CHARACTERISTICS:

• Histologically confirmed relapsed or refractory T-cell acute lymphoblastic leukemia or T-cell lymphoblastic lymphoma

  • Tumor cells should exhibit phenotypic characteristics of these diseases
• No CNS involvement requiring intrathecal or craniospinal radiotherapy
• Must not be eligible for Intergroup, Cooperative Group, or local research studies of higher priority

PATIENT CHARACTERISTICS:

Age:

• 16 and over

Performance status:

• ECOG 0-3 OR
• Karnofsky 40-100%

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• Bilirubin no greater than 2.0 mg/dL

Renal:

• Creatinine no greater than 1.5 mg/dL OR
• Creatinine clearance at least 50 mL/min

Other:

• No neuropathy grade 2 or higher
• No history of significant neurological toxicity (grade 2 or greater) associated with prior chemotherapy or radiotherapy
• No active seizure disorder
• No active infection
• No other active concurrent malignancy except curatively treated basal cell carcinoma or carcinoma in situ of the cervix
• Not pregnant or nursing
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Prior bone marrow transplantation allowed
• No concurrent allogeneic bone marrow transplantation

Chemotherapy:

• At least 3 weeks since prior chemotherapy (6 weeks for nitrosourea or mitomycin) and recovered
• No prior 506U78

Endocrine therapy:

• No concurrent systemic steroid therapy

Radiotherapy:

• See Disease Characteristics
• Prior radiotherapy allowed

Surgery:

• Not specified

Other:

• No other concurrent investigational therapy
• No concurrent treatment for seizures