OS, EFS and IKZF1 Δ2-8/ALB gene deletions
The 3-year OS and 3-year EFS in Group B were 79.3 ±8.8% and 62.4 ±9.7%, respectively, and these were significantly lower than the 3-year OS (97.7 ±2.2%, P =0.022) and 3-year EFS (83.2 ±5.8%,P =0.019) in Group A (Fig. 2). The 3-year OS and 3-year EFS of Ph-negative patients in Group B were also lower than the 3-year OS (97.6 ±2.2% vs. 84.7 ±8.1%, P =0.014) and 3-year EFS (85.2 ±5.6% vs. 59.0 ±12.9%, P =0.013) of Ph-negative patients in Group A (Fig. 3). Multivariate analysis revealed that the level of IKZF1 deletions of ≥ 1% and CNSL were independent risk factors of EFS. While the factors such as age, gender, WBC count, CNSL, BCR-ABL1 fusion gene, risk stratification and the level of IKZF1 deletions were not associated with OS (Table 3).