Early response to induction is predictive of survival in childhood Philadelphia chromosome positive acute lymphoblastic leukaemia: results of the Medical Research Council ALL 97 trial
Mike Bradburn and Sharon Love with Anindita Roy (London), Anthony Moorman (Southampton), Julie Burrett (Oxford), Sally Kinsey (Leeds), Chris Mitchell (Oxford), Ajay Vora (Sheffield), Tim Eden (Manchester), John Lilleyman, Ian Hann, Vaskar Saha (London) on behalf of the Medical Research Council Childhood Leukaemia Working Party
This study analysed the data on the outcome of children with Philadelphia positive acute lymphoblastic leukaemia (Ph+ ALL) treated on the national trial for childhood ALL, MRC ALL 97, between Jan 1997 and Jun 2002. 42 (2.3%) patients were positive for the Ph chromosome. 19 (45%) had <25% bone marrow blasts within the first 2 weeks of treatment and were defined as a Good-response group (GRG), the others as a Poor-response group (PRG). 36 (86%) achieved complete remission (CR1) at the end of induction of which 28 underwent bone marrow transplantation (BMT). The median follow up was 42 months (range 21-84 months). The 3-year estimates for event free survival (EFS) (with 95% confidence intervals) was 52% (36-66%). The EFS for the GRG and PRG were 68% (43-84%) and 39% (18-59%) respectively (p=0.03). An early response to treatment (p=0.03), was predictive for EFS and a presenting white cell count of < 50x109/L (p=0.02) for overall survival. BMT in CR1 appeared to reduce the risk of a subsequent bone marrow relapse. These results are a significant improvement on previous MRC trials, particularly for the PRG. For children with Ph+ ALL, therapeutic strategies should include early intensive therapy and bone marrow transplantation in CR1.
The analysis is at the publication preparation stage.