Value of routine bone marrow examination in pediatric acute myeloid leukemia (AML): A study of the Dutch Childhood Oncology Group (DCOG)

Background: The outcome of the treatment of pediatric acute myeloid leukemia (AML) is still disappointing, due to relatively high treatment-related mortality and relapse rates (30-40%). Past treatment protocols have called for routine screening via bone marrow aspiration (BMA) after achievement of first complete remission (CR1) to detect relapse at an early stage. However, supporting evidence for this policy is lacking for non-FAB type-M3 patients. Procedure: We therefore retrospectively studied the clinical relevance of routine BMA in an unselected cohort of all pediatric AML patients in the Netherlands. Results: Of 440 patients, data for 349 patients, of whom 148 suffered bone marrow relapse (BM-relapse), could be analyzed. A total of 1,790 BMAs had been performed, 1,648 (92%) routinely, and 142 (8%) on indication when a relapse was suspected. Forty routine BMAs showed BM-relapse (2% of all routine BMAs), while as many as 108 (76%) hematological relapses were confirmed by BMA on indication (P<0.001). Therefore, 1 in 41 routine BMAs, as opposed to 1 in 1.3 BMAs performed on indication, detected a BM-relapse. Conclusions: Routine BMA after CR1 did not significantly contribute to early detection of relapsed AML. These results suggest that BMA after achievement of CR1 should only be performed on indication or within a clinical research setting.