Age but not Philadelphia positivity impairs outcome in older/elderly patients with acute lymphoblastic leukemia in Sweden

Abstract

Objectives: Older/elderly patients with acute lymphoblastic leukemia (ALL) are poorly represented in clinical trials.

Methods: Using Swedish national leukemia registries, we investigated disease/patient characteristics, treatment choices, outcome, and the impact of an age-adapted protocol (introduced in 2009) in this population-based study of patients aged 55-85 years, diagnosed with ALL 2005-2012.

Results: Of 174 patients, 82% had B-phenotype, 11% Burkitt leukemia (excluded), and 7% T-phenotype. Philadelphia chromosome positivity (Ph+) occurred in 35%. Of the 155 B- and T-ALL patients, 80% were treated with intensive protocols, and 20% with a palliative approach. Higher age and WHO performance status ≥2 influenced the choice of palliation. Intensive, palliative, and both approaches resulted in complete remission rate 83/16/70% and 3-year overall survival (OS) 32/3/26%. The age-adapted protocol did not improve outcome. With intensive treatment, platelet count ≤35×10⁹ /L and age ≥75 years were adverse prognostic factors for OS, Ph+ was not. Male sex was an adverse prognostic factor in the 55-64 year age-group.

Conclusions: We report a high frequency of Ph+ in older/elderly patients, with no evidence of poorer outcome compared to Ph-negative disease. Overall prognosis for elderly patients with ALL remains dismal, despite the use of age-adapted treatment.

Keywords: acute lymphoblastic leukemia; chemotherapy; elderly; epidemiology.