Studying Biomarkers as a Diagnostic Tool in Samples From Younger Patients With B-Cell Acute Lymphoblastic Leukemia

STUDY SUBTYPE: Ancillary/Correlative

OBSERVATIONAL STUDY MODEL: Case-only

TIME PERSPECTIVE: Retrospective

BIOSPECIMEN RETENTION: Samples with DNA

BIOSPECIMEN DESCRIPTION: Fresh and frozen bone marrow cells

STUDY POPULATION DESCRIPTION: Patients with B-cell acute lymphoblastic samples banked at the
COG Cell Bank

SAMPLING METHOD: Non-probability sample

OBJECTIVES:

I. To determine whether we can identify individuals within a specific sub-group of pre-B
acute lymphoblastic leukemia (ALL) patients that will eventually recur.

II. To identify replication-timing changes as a biomarker for further risk prediction.

III. To identify differences between patients of similar subtype, and choose candidate
differences to analyze by methods that are compatible with frozen samples.

OUTLINE:

Archived cell samples are analyzed for replication timing by flow cytometry, microarray, and
single-cell fluorescence in situ hybridization (FISH) assays. Replication-timing results
among cases and controls are also analyzed.

Inclusion Criteria:

- Frozen viable cell samples from patients with B-cell acute lymphoblastic (ALL) of any
outcome from the Children's Oncology Group (COG) ALL Cell Bank (Part 1)

- Freshand frozen cell samples from patients with B-cell ALL with known outcomes from
the COG ALL Cell Bank (Part 2) meeting 1 of the following criteria:

- Samples from patients who experienced an early recurrence within 36 months of
diagnosis (cases)

- Samples from patients who remain in prolonged remission (controls)

- No samples meeting either of the following criteria:

- Very-high-risk features

- Philadelphia chromosome positive

- Hypodiploid

- MLL (11q23) rearranged

- Known favorable risk factors

- Hyperdiploid

- t(12;21) (ETV6/RUNX1)