Incidence of Late Chronic Anemia in Newly Diagnosed Patients with Chronic Myelogenous Leukemia Responsive to Imatinib

Abstract 3769

Anemia has been reported in about 5–8% of newly diagnosed patients with Chronic Myelogenous Leukemia (CML) treated with imatinib in the first 6 months of therapy, and has been generally regarded as transient like neutropenia and thrombocytopenia: in patients responsive to imatinib, however, it is still unclear if the prolonged treatment could induce the appearance of a late chronic anemia. To highlight this issue, we revised 104 CML patients (M/F 54/50, median age at diagnosis 58.0 years, interquartile range 43.3 – 70.2) treated at our Institution with 1^st line imatinib therapy for at least 36 months and in stable complete cytogenetic response (CCyR). At the 36^th month of imatinib treatment, a late chronic anemia (defined as Hb levels < 11 g/dl for > 6 months) was present in 16/104 patients (15.4%): the anemia was severe (Hb < 10 g/dl) in 10 patients (9.6%) and moderate/mild (Hb ≥ 10 < 11 g/dl) in 6 patients (5.8%). Clinical features at diagnosis of patients who had late chronic anemia at the 36^th month compared to the remaining 88 patients without late anemia are shown in the Table:

All patients with late chronic anemia had a low reticulocyte count and 7/16 a condition of iron deficiency with reduced serum ferritin but no clinical and instrumental sign of chronic blood loss: in this latter group, oral iron supplementation was always ineffective. Four out 16 patients (25%) needed 1 or more red cell transfusions during the follow-up. At landmark analysis from the 36th month of imatinib treatment, there was no significant difference in the cumulative 4-year overall survival for patients with and for those without late chronic anemia (80%, 95% CI 44.8 – 100%, vs 94%, 95%CI 85.8 – 100%, respectively; p=0.068). In conclusion, the occurrence of a late chronic anemia during long-lasting treatment with imatinib has been observed in > 15% of our responsive patients and was severe in about 10% of cases: its occurrence seems more common in elderly patients with higher Sokal score at diagnosis. Late chronic anemia does not seem to affect OS, but the real impact should be evaluated on a large cohort of patients.