Biomarkers to Classify Young Patients With Acute Lymphoblastic Leukemia (ALL) and Remission Induction Therapy in Young Patients With B-Precursor ALL

DISEASE CHARACTERISTICS:

* Meets one of the following sets of criteria:

  * Classification study:

    * Newly diagnosed ALL\*
    * Must have one of the following:

      * ≥ 25% blasts in bone marrow
      * ≥ 100,000/μl peripheral blood WBC with ≥ 75% blasts, if bone marrow aspiration is omitted for any reason other than medical contraindication
      * ≥ 30,000/μl WBC with ≥ 75% blasts, if bone marrow aspiration is omitted because of medical contraindication
    * Immunophenotype and Wright's stain morphology of blast cells consistent with acute lymphocytic leukemia
    * ≤ 21 years of age at the time of diagnosis
    * No previous registration on 9900
    * Samples must be sent for local institution and COG Reference Laboratory studies NOTE: \*It is urged that a bone marrow aspiration be performed for every patient with suspected ALL. However, a marrow is not required for patients with ≥ 100,000/μl peripheral blood WBC and ≥ 75% blasts or for those patients whose clinical condition precludes performing the procedure safely. Patients with a medical contraindication to the procedure must be discussed with one of the study coordinators and must have a peripheral blood WBC of ≥ 30,000/μl with ≥ 75% blasts.
  * Induction therapy study:

    * Patients must have a confirmed diagnosis of B-precursor acute lymphoblastic leukemia
    * Patients must be 1.001 to 21.999 years at diagnosis NOTE: Patients meeting all of the above eligibility criteria are eligible for registration on 9900 whether or not they are to be entered on a COG frontline protocol for treatment of newly diagnosed ALL. Registration on 9900 is required for all legacy POG institution patients in order to be eligible for entry on the following COG ALL studies, which are either currently open or only temporarily closed: P9407, 9904, 9905, 9907, AALL0031 and AALL00P2.

PATIENT CHARACTERISTICS:

* See Disease Characteristics

PRIOR CONCURRENT THERAPY:

* Previously untreated, with the following exception:

  * Steroid treatment\* in the 48-hour period just prior to study entry will be allowed provided that a physical examination and CBC with differential were performed IMMEDIATELY prior to beginning steroids and results of both are known NOTE: \*Patients on chronic steroid treatment for another disease are NOT eligible for a COG New ALL protocol.