Inclusion Criteria:

• Patient has newly diagnosed acute leukemia:
  • > 25% blasts on a bone marrow (BM) aspirate; or
  • If a BM aspirate is not obtained or is not diagnostic of acute leukemia, the diagnosis can be established by a pathologic diagnosis of acute leukemia on a BM biopsy; or
  • A complete blood count (CBC) documenting the presence of at least 1,000/uL circulating leukemic blasts.
• Adequate samples must be provided to the reference and/or COG-approved cytogenetics laboratories to allow completion of the studies needed for risk-stratification:
  • If a BM aspirate is not performed, or adequate material cannot be obtained, peripheral blood (PB) can be substituted for BM if there are at least 1,000 circulating blasts/uL (i.e., a white blood cell [WBC] count of 10,000/uL with 10% blasts or a WBC count of 5,000/uL with 20% blasts);
  • If an adequate BM aspirate cannot be obtained and there are fewer than 1,000/uL PB blasts, the patient is not eligible for AALL08B1 or a frontline COG ALL clinical trial.
• Patient has suspected ALL:
  • Patients whose blast morphology is obviously myeloid, or whose blasts are myeloperoxidase positive, should not be enrolled on AALL08B1; however, patients with true biphenotypic or bilineage leukemia (i.e., patient presents with blasts with significant expression of multiple lymphoid and myeloid markers such that assignment to a single lineage is not possible) are eligible to enroll in AALL08B1 for cell banking.
• Samples must be sent to a COG-approved cytogenetics laboratory, and COG Reference Laboratory studies.
• All patients and/or their parents or legal guardians must sign a written informed consent.
• All institutional, Food and Drug Administration (FDA) and National Cancer Institute (NCI) requirements for human studies must be met.

Exclusion Criteria:

• Patient must not have received prior cytotoxic therapy except for steroids or intrathecal chemotherapy.
• Patient must not have secondary ALL that developed after treatment of a prior malignancy with cytotoxic chemotherapy.