Clinical impact ofBAALCexpression in high-risk acute promyelocytic leukemia

Although overexpression of the brain and acute leukemia, cytoplasmic (BAALC) gene is associated with primary resistant disease and shorter relapse-free, disease-free, and overall survival in different subsets of acute myeloid leukemia (AML), little is known about its clinical impact in acute promyelocytic leukemia (APL). Using real-time reverse transcriptase polymerase chain reaction, we showed thatBAALCexpression is significantly lower in APL compared with other subsets of AML (P< .001). We also demonstrated thatBAALCoverexpression was associated with shorter disease-free survival (DFS) (hazard ratio [HR], 4.43; 95% confidence interval [CI], 1.29-15.2;P= .018) in 221 consecutive patients (median age, 35 years; range, 18-82 years) with newly diagnosed APL homogeneously treated with all-transretinoic acid and anthracycline-based chemotherapy. Cox proportional hazard modeling showed thatBAALCoverexpression was independently associated with shorter DFS in the total cohort (HR, 5.26; 95% CI, 1.52-18.2;P= .009) and in patients with high-risk disease (ie, those with initial leukocyte counts >10 × 109/L) (HR, 5.3; 95% CI, 1.14-24.5;P= .033). We conclude thatBAALCexpression could be useful for refining risk stratification in APL, although this needs to be confirmed in independent cohorts.