FACTORS PREDICTING COMPLETE REMISSION AND SUBSEQUENT DISEASE-FREE SURVIVAL AFTER A 2ND COURSE OF INDUCTION THERAPY IN PATIENTS WITH ACUTE MYELOGENOUS LEUKEMIA RESISTANT TO THE FIRST

Patients with newly diagnosed acute myelogenous leukemia (AML) with pe rsistent leukemia after their first course (CO1) of induction chemothe rapy are generally given a second similar couse, although their outcom e is known to be worse than CO1 responders even when a complete remiss ion (CR) is achieved. To identify specific patients who should or shou ld not receive a second induction course identical to the first we ana lyzed outcome in 370 patients with persistent AML after CO1 who receiv ed a second identical course. One hundred and forty-two (38%) achieved CR on this course; median subsequent disease-free survival (DFS) in t hese 142 was 29 weeks and 10% were alive in CR at 5 years. The 5-year DFS of CO2 responders was significantly lower than that of CO1 respond ers (10 vs 24%, P < 0.001). Logistic regression identified pretreatmen t cytogenetic abnormalities (except inv 16, t(8;21), or t(15;17)), pre sence of an antecedent hematologic disorder or secondary AML as each h aving unfavorable prognostic import similar to the case in untreated p atients. Treatment with 'high-dose' rather than standard-dose cytarabi ne increased the probability of 2nd course CR. The occurrence of pneum onia, sepsis, or major hemorrhage were prognostically unfavorable, pri marily in the high-dose cytarabine group, and, once in CR, DFS was sho rter in this group. Equations predicting probability of 2nd course CR were derived, If validated prospectively these could be used to assign patients to either receive a second course of initial induction thera py or to change to salvage or investigational therapy after the first course. Alternatively, they could be used to stratify patients enterin g a prospective randomized trial comparing these two strategies.