title: Hydroxycarbamide treatment in sickle cell disease: estimates of possible leukaemia risk and of hospitalization survival benefit.
abstract: Using health insurance claims databases we compared the frequency/incidence of acute myeloid leukaemia (AML) and inpatient mortality in sickle cell disease (SCD) subjects taking (n = 1051), or not taking (n = 9203) hydroxycarbamide (HC). Patients taking HC were older (median 19 vs. 17 years of age), had a higher proportion of males (53% vs. 38%), and their median hospitalizations per year was five times greater than in SCD patients not on HC (all P < 0·001). No new AML cases occurred in HC-treated paediatric SCD patients. For adults, the new AML incidence with HC exposure was 10·7/10 000 patient years, vs. 4·0/10 000 patient years in subjects not on HC (P = 0·2), a possible AML risk ratio of 3·18. Adjustment for a probable database bias for AML diagnosis/ascertainment lowered the risk ratio to 0·94 (95% confidence interval = 0·16-5·47). Despite their greater disease severity, the inpatient mortality in SCD adults prescribed HC (0·29%) was lower than that of patients not taking the drug (0·42%, P = 0·032). In this SCD population we find no increased risk for AML with HC treatment. If such a risk is eventually proven, it will probably be lower than that for drugs with known AML association. By contrast, HC treatment appears to confer a survival benefit.
authors.affiliation: Center for Sickle Cell Disease, Howard University, Washington, DC, USA.
authors.forename: Oswaldo
authors.initials: O
authors.lastname: Castro
authors.forename: Mehdi
authors.initials: M
authors.lastname: Nouraie
authors.forename: Patricia
authors.initials: P
authors.lastname: Oneal
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000755:Anemia, Sickle Cell / Q000188:drug therapy / Q000401:mortality; D000986:Antisickling Agents / Q000008:administration & dosage / Q000009:adverse effects; D002648:Child; D016208:Databases, Factual; D018572:Disease-Free Survival; D005260:Female; D006760:Hospitalization; D006801:Humans; D006918:Hydroxyurea / Q000008:administration & dosage / Q000009:adverse effects; D015470:Leukemia, Myeloid, Acute / Q000209:etiology / Q000401:mortality; D008297:Male; D012307:Risk Factors; D012737:Sex Factors; D015996:Survival Rate
chemical_list: D000986:Antisickling Agents; D006918:Hydroxyurea
keywords: acute myeloid leukaemia risk; inpatient survival; sickle cell disease; treatment