Treatment outcomes in patients older than age 60 with acute myeloid leukemia (AML) in the nonclinical trial setting.

Abstract

6572 Background: Optimal treatment of older adults with AML remains challenging. While AML tends to be a disease of older adults, this population experiences greater treatment-related toxicity and worse overall survival than younger patients. Only fit older adults enter clinical trials and thus the results may not apply to the entire population. Methods: We conducted a retrospective analysis of patients > 60 years with AML (APL excluded) diagnosed prior to 2008 with IRB approval. The association of clinical factors (age, sex, comorbidities, prior chemotherapy), leukemia (prior myelodysplastic syndrome or myeloproliferative neoplasm, cytogenetics, WBC count), and therapy (induction chemotherapy, palliative chemotherapy, and best supportive care) as they relate to overall survival was evaluated using bivariate and multivariate regression analyses. Results: Of 87 patients (median age 73), 45% were male, 58% had high risk cytogenetics, 38% had prior MDS/MPD, 92% were chemotherapy naive, and 21% were in the high/very high Charlson risk class. The majority (67%) received standard dose induction chemotherapy (IC), 9% received (palliative intent) low-dose chemotherapy (LDC), and 24% received best supportive care (BSC). The median overall survival (OS) of the entire cohort was 2.5 months. On bivariate analysis high WBC (>50,000 at presentation) was negatively associated (1.0 vs 2.7 months p <0.01) with survival. OS for IC, LDC, and BSC were 3.1, 2.8, and 0.7 months, respectively (p=0.001). On multivariable analysis, IC conferred longer survival when compared to LDC and BSC combined (OR 0.33 CI 0.2-0.6, p<0.001). High WBC was associated with a decreased survival time (OR 2.96 CI 1.6-5.5, p=0.02). Mortality during induction or consolidation chemotherapy was 38%. At 5-year follow-up, only 4 patients were alive. Conclusions: In a non-clinical trial setting, OS of older adults with AML remains dismal. While IC offers a chance of longer survival, mortality with IC is unacceptably high. Further studies are required to identify and validate tools for risk stratification in older adults with AML as well as to utilize therapies with an improved toxicity profile.