Three Versus Five Years of Maintenance Therapy Are Equivalent in Childhood Acute Lymphoblastic Leukemia: A Report From the Childrens Cancer Study Group

Childrens Cancer Study Group protocol 141 (CCG-141), a randomized trial, was designed in part to compare 3 v 5 years of maintenance therapy, to evaluate the role of late reinduction, and to identify factors that predict relapse after 3 years of continuous complete remission (CCR) in acute lymphoblastic leukemia (ALL). Of 880 patients entered on study, 827 (94%) achieved complete remission and 499 (56.7%) were in CCR after 3 years of maintenance therapy. Boys were required to have negative testicular biopsies before randomization. A total of 481 patients were eligible for the duration of therapy phase of the study. Of the 310 (64.4%) randomly assigned patients, 101 were entered on regimen A: discontinue therapy; 105 on regimen B: reinduction for 4 weeks, then discontinue therapy; and 104 on regimen C: continue maintenance therapy for 2 more years, then discontinue. After a median follow-up of over 72 months, no significant differences in disease-free survival (DFS) or survival were noted in the three regim...