The majority of patients 70 years or older with acute myeloid leukemia (AML) have a poor prognosis and may not benefit from intensive chemotherapy, a study by M. D. Anderson Cancer Center researchers indicates.
Patients older than 55 years have been excluded from most clinical trials of AML and so physicians have had to infer that therapies that are effective in younger patients will work in older patients too. Hagop Kantarjian, MD, and colleagues studied 446 patients ≥70 years of age with AML (≥20 blasts) who were treated with cytarabine-based intensive chemotherapy between 1990 and 2008 to identify groups at risk for high induction (8-week) mortality.
After excluding patients with favorable karotypes, the overall complete response rate was 45%; however, 154 patients died within the first 8 weeks of treatment, as a result of ineffective therapy or treatment toxicity.
The researchers identified four factors predictive of dying within 8 weeks:
- Age > 80 years
- ≥ three genetic abnormalities
- Poor performance (ECOG score 2-4)
- Creatinine levels > 1.3 mg/dL
Nearly three quarters (72%) of patients had at least one or these factors, and the more risk factors, the worse the outcome with intensive chemotherapy. Eight-week mortality was 16% in patients with none of these factors; 31% with one; 55% with two; and 71% with three.
Clinicians may wish to consider less intensive treatment strategies for patients with one or more risk factors, the researchers suggest.