Changes in the Hierarchy of Risk Factors with Older Age in De-Novo Acute Myeloid Leukemia (AML).
Authors: Buchner Thomas , Berdel Wolfgang E. , Schoch Claudia , Haferlach Torsten , Serve Hubert L. , Kienast Joachim , Schnittger Susanne , Kern Wolfgang , Tchinda Joelle , Reichle Albrecht , Staib Peter , Ludwig Wolf-Dieter , Aul Carlo , Cristina Sauerland Maria , Heinecke Achim , Josef Wormann Bernhard , Hiddemann Wolfgang 
Published: October 2019

After recent reports addressed prognostic factors and outcome in older age AML (Burnett et al. Blood106:162a,2005; Wheatley et al. Blood106:199a,2005; Appelbaum et al. Blood107:3481–5,2006; Farag et al. Blood108:63–73,2006) we evaluated 764 patients of 60–85 (median 66) years reduced to those with de-novo AML, known karyotype, and identical consolidation-maintenance chemotherapy, who were part of the 1992 and 1999 multicenter randomized trials by the German AMLCG (Buchner et al. J Clin Oncol21:4496–504,2003;24:2480–9,2006). 521 patients were 60 -< 70 (median 64) and 243 patients were 70–85 (median 73) years of age. 64% and 50% patients respectively went into complete remission, 24% and 29% remained with persistent AML, 12% and 21% succumbed to early and hypoplastic death (p<.001). The overall survival in the younger (60- < 70y) and older (70+) patients was at a median of 13 vs 6 months and 18% vs 8% survived at 5 years (p<.001). Once in complete remission, the remission duration was 14 vs 12 months (median) and equally 18% at 5 years; the relapse-free survival is 13 vs 11 months (median) and 14% vs 13% at 5 years. While all patients were randomized up-front for 2 versions of induction either by TAD-HAM (HAM, high-dose araC 1g/m2x6 and mitox 10mg/m2x3) or by HAM-HAM, response and survival did not differ between the two arms in neither age group. In contrast to response and survival between the younger (60-<70y) and older (70+y) age group corresponding differences in the risk profiles were missing. Thus, favorable/intermediate/unfavorable karyotypes accounted for 8% vs 4% / 67% vs 73% / and 25% vs 24% of patients (p=.073); WBC > 20.000/ccm was found in 40% vs 39% (p=.52); LDH > 700U/L was remarkably 26% vs 18% (p=.014), and the day 16 b.m. blasts ≥ 10% accounted for 41% and 41% of patients.

Conclusion:

Approximately 50% of patients 70 years of age or older benefit from standard or intensive chemotherapy by complete remission which continues after 1 year in about 50% of responders. The inferior overall survival in the patients of 70+ versus those of 60- < 70 years is mainly explained by more frequent early and hypoplastic death (21% vs 12%) (p=.0016) and death with persistent AML (26% vs 18%) (p=.0145); while death in remission (7% vs 6%), relapse rate (50% vs 53%) and death after relapse (21% vs 26%) did not show this trend. In contrast to the important differences in outcome, established risk factors such as cytogenetic groups, WBC, and early blast clearance show concordance between the two age groups. The even lower LDH may support assumptions of older age AML as a less proliferative disease (Appelbaum et al. Blood 107:3481–5,2006). Thus, the hierarchical risk profiles cannot predict the age related outcome beyond 60 years in patients with de-novo AML.