Long-term survival of patients with acute myeloid leukemia: updated results from two trials evaluating postinduction chemotherapy.
BACKGROUND
Although the prospect of long-term disease free survival (LFS) after chemotherapy for acute myeloid leukemia (AML) is widely accepted, few studies have reported long-term survival data. The authors therefore updated results from a 1981 report on a study conducted by the University of Minnesota Masonic Cancer Center (UMMCC) and a 1989 report on a study conducted by the North American Marrow Transplant Group (NAMTG).


METHODS
Minimum follow-up of 21.6 years for living patients was obtained for 26 patients who received weekly cytarabine and 6-thioguanine maintenance therapy after achieving complete remission (CR) in the UMMCC study. Minimum follow-up of 7.7 years was obtained on 87 patients treated with high dose cytarabine intensification in first remission in the NAMTG study.


RESULTS
In the UMMCC study, the LFS rate was 28% and the overall survival rate was 15%. Nineteen percent of patients died in first CR at 1.3-12 years. Three patients remain alive in initial CR at >20 years. In the NAMTG study, the LFS rate was 49% and the overall survival rate was 45%. A total of 38 patients (44%) remain alive in initial CR at a median of 11.4 years after diagnosis. An additional patient is alive in second CR at 8.6 years after diagnosis. In both studies, relapses after 3 years were relatively uncommon (11-12%).


CONCLUSIONS
Chemotherapy alone is curative in more than 40% of AML patients who achieve CR. Short-term, high dose cytarabine intensification appeared more efficacious, without increased toxicity, compared with low dose, prolonged cytarabine-based maintenance. However, for patients who cannot receive intensification, prolonged, low dose maintenance therapy is an acceptable alternative for achieving cure. A minimum follow-up of 3 years is a reasonable predictor of long-term survival and should be obtained in studies evaluating therapeutic outcome in cases of AML.
Bloomfield
C D
CD
Roswell Park Cancer Institute, Buffalo, New York, USA.
Herzig
G P
GP
Peterson
B A
BA
Wolff
S N
SN
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D003561:Cytarabine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007951:Leukemia, Myeloid / Q000188:drug therapy* / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D012074:Remission Induction; D016019:Survival Analysis; D013997:Time Factors
D000964:Antimetabolites, Antineoplastic; D003561:Cytarabine