Comparison of outcomes in mixed phenotype acute leukemia patients treated with chemotherapy and stem cell transplantation versus chemotherapy alone

• Mixed phenotype acute leukemia (MPAL) is a complex entity with heterogeneous characteristics.
• AlloHSCT after chemotherapy offers a survival advantage compared with chemotherapy only in MPAL patients.
• Patients in remission before transplantation may experience a better outcome.

The optimal treatment approach for mixed phenotype acute leukemia (MPAL) remains unknown, and prognostic factors for treatment outcomes need to be identified. In this study, 66 patients diagnosed with MPAL according to criteria published by the WHO in 2008 were retrospectively assessed to evaluate the effectiveness of treatment and identify predictive variables. Five patients died of severe infection after the first induction chemotherapy, 29 received alloHSCT after induction (HSCT group), and 32 received only chemotherapy (chemotherapy group). The 3-year OS and DFS estimates for the entire cohort were 45% and 38%, respectively, and the 3-year OS differed significantly between the HSCT and chemotherapy-only groups (77% versus 16%). Using multivariate analyses, we identified disease burden as a prognostic factor for transplantation outcome, with the 3-year OS being 80% among patients who achieved remission and only 45% among patients in cases of nonremission. Our results indicate that alloHSCT after chemotherapy offers a survival advantage compared with chemotherapy only, and patients in remission before transplantation may experience a better outcome.