RATIONALE: Studying samples of bone marrow and blood from patients with cancer in the laboratory may help doctors predict how well patients will respond to treatment.

PURPOSE: This research study is studying biomarkers in bone marrow and blood samples from older patients with acute myeloid leukemia treated with cytarabine-based therapy.

OBJECTIVES:

Primary

• To validate a pre-specified proteomic classifier to predict the likelihood of complete response (CR) to cytarabine-based induction chemotherapy in older patients with non-M3 acute myeloid leukemia.

Secondary

• To identify signaling nodes associated with risk of relapse among these patients who achieve a CR to induction chemotherapy.

OUTLINE: This is a multicenter study.

Previously collected bone marrow and peripheral blood samples are analyzed to validate the association of a pre-specified proteomic signature with clinical response via flow cytometry.

DISEASE CHARACTERISTICS:

• Treated on EST-1490, E-3993, or ECOG-E3999
• Bone marrow and peripheral blood samples collected at diagnosis and before induction chemotherapy available
• No M3 disease

PATIENT CHARACTERISTICS:

• Not specified

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics

Samples from patients enrolled on E3999 and E3993 from whom samples were submitted for research