Lack of benefit of early detection of relapse after completion of therapy for acute lymphoblastic leukemia

Background. Although most pediatric oncologists obtain routine blood counts in patients who have completed treatment for acute lymphoblastic leukemia (ALL), the value of this practice is unproven. We therefore sought to determine if detection of relapse by blood counts before the onset of symptoms provided any clinical benefit. Procedures. We performed a retrospective review of 72 patients with ALL who suffered isolated or combined hematologic relapses after the completion of therapy. We compared attainment of second remission and survival after relapse among patients who were asymptomatic and diagnosed by routine blood count, those who had symptoms suggestive of relapse and were diagnosed at the time of a scheduled follow-up, and those whose relapse was diagnosed because of the appearance of symptoms. Results. Only 11% of patients who suffered a relapse were asymptomatic at the time of relapse and diagnosed solely by routine blood counts. There were no significant differences in the survival distributions for the three groups of patients. Conclusions. In this cohort of patients with relapsed ALL, we found no evidence that detection of relapse by routine blood counts before the onset of symptoms leads to a better outcome.