Prognostic Effect of CD20 Expression in Adult B-cell Acute Lymphoblastic Leukemia.

INTRODUCTION

The expression of the CD20 on adult B-cell acute lymphoblastic leukemia (ALL-B) has generally been associated with a poor prognosis, and several studies have explored the incorporation of rituximab into the therapeutic regimen for adult ALL-B patients, with a positive effect on event-free survival (EFS).

PATIENTS AND METHODS

We analyzed the prognostic value of CD20 expression and the effect of rituximab for the treatment of Hispanic adult ALL-B patients. We performed a retrospective study of 152 ALL-B patients treated from 2009 to 2016. The patient characteristics and treatment outcomes were analyzed according to CD20 expression (CD20 vs. CD20), age group, and treatment with rituximab.

RESULTS

CD20 expression was positive for 47.7% of patients (n = 72). Excluding the patients who had received rituximab, the overall survival (OS) was greater for the CD20 patient subgroup than for the CD20 subgroup (11.2 vs. 6.9 months; 95% confidence interval [CI], 7.43-14.9; P = .008). In the CD20 subgroup, 10 patients (7.2%) received treatment with rituximab, with 100% reaching complete remission (CR) 4 weeks after treatment. In the 18- to 39-year age group, CD20 patients treated with rituximab had EFS and OS that was not reached. In addition, for CD20 patients who received with chemotherapy, EFS was 3.9 months (95% CI, 0.6-7.2 months; P = .025) and OS was 7.2 months (95% CI, 3.37-11.0; P = .013). Multivariate analysis showed that the use of rituximab was independently associated with OS and CR at 4 weeks after induction.

CONCLUSION

CD20 expression in adult ALL-B is associated with decreased OS. Treatment with rituximab can increase OS, EFS, and CR in the 18- to 39-year age group.