The long-term impact of in vitro drug sensitivity on risk stratification and treatment outcome in acute lymphoblastic leukemia of childhood (CoALL 06-97).

Background: In a study of childhood acute lymphoblastic leukemia (CoALL 06-97 study), the in vitro sensitivity of the patients' cells to prednisolone, vincristine and asparaginase was introduced as a new additional risk parameter for treatment stratification. In parallel in vivo treatment response was assessed by determining the presence and extent of minimal residual disease in a subset of patients (n=224). Here we report the long-term impact of in vitro sensitivity-based risk stratification according to survival and compare the results of in vitro sensitivity with in vivo response.