In vitro cellular drug sensitivity at diagnosis is correlated to minimal residual disease at end of induction therapy in childhood acute lymphoblastic leukemia

Leukemic cells from 85 children with newly diagnosed precursor B-lineage ALL were tested for in vitro drug sensitivity to a panel of anti-cancer drugs. Minimal residual disease (MRD) was measured by RQ-PCR. There was a significant correlation between MRD day 29 and in vitro sensitivity to prednisolone (p < 0.001) and doxorubicin (p = 0.017), drugs administered during induction therapy. In patients with t(12;21) (n = 20), in vitro sensitivity to doxorubicin was an independent factor for MRD <0.1% (p = 0.031; R2 = 0.66). Thus, data show that in vitro drug sensitivity at diagnosis is correlated to cell kill during induction therapy as measured by MRD day 29.