Combination Chemotherapy in Treating Young Patients With Newly Diagnosed T-Cell Acute Lymphoblastic Leukemia or T-cell Lymphoblastic Lymphoma

Inclusion Criteria:

   - T-ALL patients must be enrolled on AALL08B1 prior to treatment and enrollment on
   AALL0434

   - Patients must have newly diagnosed T-ALL or T-lineage lymphoblastic lymphoma (T-NHL)
   stage II-IV; B-lineage lymphoblastic lymphoma will not be eligible for this study; a
   diagnosis of T-ALL is established when leukemic blasts lack myeloperoxidase or
   evidence of B-lineage derivation (cluster of differentiation [CD]19/CD22/CD20), and
   express either surface or cytoplasmic CD3 or two or more of the antigens CD8, CD7,
   CD5, CD4, CD2 or CD1a; if surface CD3 is expressed on all leukemic cells, additional
   markers of immaturity, including transmission disequilibrium test (TdT), CD34 or CD99
   will be assessed for expression; cases with uncertain expression will receive
   additional review within the appropriate Children's Oncology Group (COG) reference
   laboratory

   - T-NHL PATIENTS:

      - For T-NHL patients with tissue available for flow cytometry, the criterion for
      diagnosis should be analogous to T-ALL; for tissue processed by other means (i.e.
      paraffin blocks), the methodology and criteria for immunophenotypic analysis to
      establish the diagnosis of T-NHL defined by the submitting institution will be
      accepted

   - Prior therapy restrictions

      - Patients shall have had no prior cytotoxic chemotherapy with the exception of
      steroids and/or IT cytarabine

      - IT chemotherapy with cytarabine is allowed prior to registration for patient
      convenience; this is usually done at the time of the diagnostic bone marrow or
      venous line placement to avoid a second lumbar puncture; (Note: the CNS status
      must be determined based on a sample obtained prior to administration of any
      systemic or intrathecal chemotherapy, except for steroid pretreatment); systemic
      chemotherapy must begin within 72 hours of this IT therapy

      - Patients diagnosed as having T-NHL or T-ALL with respiratory distress or
      hyperleukocytosis may require steroids prior to the initiation of additional
      systemic therapy; they are eligible for AALL0434 and will be stratified, based on
      the initial complete blood count (CBC); steroid pretreatment may alter the risk
      group assessment; if the T-ALL patient's clinical status precludes a lumbar
      puncture within 48 hours of the initiation of steroid therapy, T-ALL patients
      CANNOT be classified as low risk and will be Intermediate or high risk based on
      the results of the day 29 marrow as above; patients with T-NHL who receive
      steroid pre-treatment will be classified as high risk; the dose and duration of
      previous steroid therapy should be carefully documented

      - For the management of airway compromise, patients who have received emergent
      chest irradiation up to 600 cGy will be eligible for this study

   - Patients with a prior seizure disorder requiring anti-convulsant therapy are not
   eligible to receive nelarabine; in addition, patients with pre-existing grade 2 (or
   greater) peripheral neurotoxicity, as determined prior to Induction treatment by the
   treating physician or a neurologist, are not eligible to receive nelarabine; these
   restrictions in eligibility are designed to prevent excessive nelarabine-induced
   central and peripheral neurotoxicity in at-risk patients; for the purposes of this
   study, this includes any patient that has received anticonvulsant therapy to
   prevent/treat seizures in the prior two years

Exclusion Criteria:

   - Pregnant or lactating females are ineligible

   - Patients with Down syndrome are ineligible to enroll onto this study

   - For T-NHL patients the following additional exclusion criteria apply:

      - B-precursor lymphoblastic lymphoma

      - Morphologically unclassifiable lymphoma

      - Absence of both B-cell and T-cell phenotype markers in a case submitted as
      lymphoblastic lymphoma

      - CNS3-positive or testicular involvement