Background
Temozolomide-induced aplastic anemia (TIAA) is a rare but highly challenging complication of temozolomide (TMZ) therapy. Evidence describing prognosis, clinical characteristics, and treatment of this entity is very limited.
Methods
We performed a multicenter, 22-year observational cohort study of patients with central nervous system (CNS) malignancies treated with temozolomide who developed TIAA, retrospectively analyzing prognosis, complications, and recovery. TIAA was defined using adapted evidence-based severe aplastic anemia criteria incorporating profound cytopenias and a minimum duration (4 weeks) without hematologic recovery.
Results
Of 3,821 patients with CNS malignancies receiving TMZ, 34 patients (0.89%) met criteria for TIAA. Onset was rapid, with 29 patients (85.3%) developing TIAA before completing a second TMZ cycle. 23 patients (67.6%) ultimately achieved a hematologic recovery. Patients without recovery were more likely to develop febrile neutropenia (72.7% vs. 30.4%, P=0.03), infectious complications (45.5% vs. 8.7%, P=0.02), require hospitalization (81.8% vs. 43.5%, P=0.04), and die (100.0% vs. 60.9%, P=0.02). Median overall survival from TIAA diagnosis was 752 days in patients achieving a partial hematologic recovery versus 28 days in those who did not (P<0.0001). 29 patients (85.3%) received one or more hematopoietic growth factors; hematologic recovery rates were higher in patients receiving thrombopoietin receptor agonists (81.8% vs. 60.9%) but were not higher in patients receiving granulocyte colony stimulating factors.
Conclusions
TIAA occurs in <1% of patients receiving TMZ for CNS malignancies, but is highly morbid when it occurs and frequently fatal in the one-third of patients not achieving hematologic recovery. Thrombopoietin receptor agonists may improve the likelihood of a hematologic recovery.