Comparison of bone marrow aspirates and biopsies in pediatric patients with ALL at days 7 and 14 of induction therapy.

The percentage of blasts in the bone marrow aspirates at day 7 or 14 of induction therapy in pediatric ALL patients is an indicator of rapid early response and an independent prognostic factor for long term outcome. Discrepancies between the percentages of blasts in bone marrow aspirates compared to biopsies have been reported. In a retrospective study on 44 consecutive patients diagnosed with ALL between 1998 and 2001, important differences were observed in the percentage of blasts between bone marrow aspirates and biopsies at days 7 and 14 of induction therapy.