Biomarker Study in Bone Marrow Samples From Patients With T-Cell Acute Lymphoblastic Leukemia

OBJECTIVES:

• To confirm an association between induction failure (IF) status predicted by a previously identified 116-member genomic classifier and actual induction therapy outcome observed on COG study AALL0434.
• To explore whether there is an association between early relapse (as defined by bone marrow or extramedullary relapse within 18 months of diagnosis) predicted by previously identified 5-member (primary) and 57-member (secondary) genomic classifiers, and actual relapse status at 18 months on COG study AALL0434. (Exploratory)

OUTLINE: RNA from cryopreserved bone marrow samples are analyzed for gene expression by microarray methods. Samples are then compared with the 116-member genomic classifier.

DISEASE CHARACTERISTICS:

• Newly diagnosed T-cell acute lymphoblastic leukemia
• Cryopreserved bone marrow from the Children Oncology Group (COG) Cell Bank of patients enrolled on COG-AALL03B1 and COG-AALL0434, including the following:

• 30 samples from patients who had > 25% bone marrow blasts at day 29 (induction failure [IF] cases)
• Samples of cases of bone marrow and/or CNS relapse occurring within the first 18 months of treatment
• Random samples of 105 non-IF cases who achieved remission at the end of induction therapy (at least 18 months)

PATIENT CHARACTERISTICS:

• Not specified

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics