Different Therapies in Treating Infants With Newly Diagnosed Acute Leukemia

DISEASE CHARACTERISTICS:

Inclusion criteria:

* Diagnosis of acute lymphoblastic leukemia (ALL) or biphenotypic leukemia meeting the following criteria:

  * Based on European Group for the Classification of Acute Leukemia (EGIL) diagnostic criteria
  * Newly diagnosed disease
  * Verified by morphology and confirmed by cytochemistry and immunophenotyping

    * Trephine biopsy is recommended (unless diagnosis can be confirmed by peripheral blood examination) in the event that bone marrow aspiration results in a "dry tap"
* Must have MLL gene rearrangements documented by split-signal fluorescence in situ hybridization and meets 1 of the following risk criteria:

  * Low-risk disease, defined as all MLL germline cases
  * Medium-risk disease, defined by 1 of the following criteria:

    * MLL status unknown
    * MLL rearranged AND age \> 6 months
    * MLL rearranged AND age \< 6 months AND WBC \< 300 x 10\^9/L AND prednisone good response
  * High-risk disease, defined by MLL rearrangement AND meets the following criteria:

    * Age at diagnosis \< 6 months (i.e., \< 183 days)
    * WBC ≥ 300 x 10\^9/L AND/OR prednisone poor response
* Minimum donor and stem cell requirements for high-risk patients undergoing stem cell transplantation:

  * Donor meeting 1 of the following criteria:

    * HLA-identical sibling
    * Very well-matched related or unrelated donor
    * Must be HLA compatible in 10/10 or 9/10 alleles by 4 digit/allele high-resolution molecular genotyping
  * Stem cell source

    * Bone marrow (preferred source) OR peripheral blood stem cells of filgrastim \[G-CSF\]-stimulated donors OR cord blood

      * Highly-matched unrelated umbilical cord blood (UCB) (\> 7/8 matches identified by high-resolution typing) accepted if a sibling donor is not able to donate bone marrow AND UCB with a sufficient number of nucleated cells (NCs) (i.e., \> 1.5 x 10\^7/kg recipient body weight \[BW\]) is cryopreserved
  * Must have ≥ 3 x 10\^8 NCs/kg BW OR 3 x 10\^6/kg BW CD34-positive cells available for transplantation
* CNS or testicular leukemia at diagnosis allowed

Exclusion criteria:

* Mature B-ALL, defined by the immunophenotypical presence of surface immunoglobulins or t(8;14) and breakpoint as in B-ALL
* Presence of the t(9;22) (q34;q11) or bcr-abl fusion in the leukemic cells (if data are not known, patient still may be eligible)
* Relapsed ALL

PATIENT CHARACTERISTICS:

* See Disease Characteristics

PRIOR CONCURRENT THERAPY:

* More than 4 weeks since prior systemic corticosteroids

  * Corticosteroids by aerosol are allowed