CONTINUING (MAINTENANCE) THERAPY IN LYMPHOBLASTIC-LEUKEMIA - LESSONS FROM MRC UKALL-X

The relationship between the prescribed dose of drugs during continuin g (maintenance) therapy the degree of marrow suppression caused, and s ubsequent event-free survival was examined in a cohort of 740 children with lymphoblastic leukaemia treated on MRC UKALL X. Girls, younger c hildren, and patients who had received intensification treatment, were prescribed lower doses of mercaptopurine, became neutropenic more rea dily, and had more interruptions of treatment. Children who had one or more episodes of neutropenia with a count of <0.5 x 10(9)/l bad a bet ter prognosis than those who never became neutropenic. We conclude tha t early intensification treatment influences the probability of neutro penia during continuing treatment and that patients exhibiting myelosu ppression during this phase of treatment have a better chance of prolo nged remission.