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.