Abstract
In adult B cell precursor acute lymphoblastic leukemia (BCP-ALL), CD20 expression has generally been associated with an adverse prognosis. Incorporating rituximab to standard of care is found to improve the outcome of CD20+ BCP-ALL. The aim of this study is to estimate the prognostic effect of CD20 expression and the impact of rituximab in BCP-ALL in Saudi Arabia.
We performed a retrospective study of 55 Saudi adult patients with BCP-ALL in King Fahad Specialist Hospital in Dammam from 2008 to 2017.
The proportion of CD20+ cases was approximately 55%. Excluding rituximab-treated patients, the 5-year overall survival (OS) rate of CD20+ patients was lower than CD20− patients (56% vs. 66%; P = .62). Among CD20+ patients, the proportion that received rituximab was approximately 27%. Comparing CD20+ patients with and without rituximab, all patients who received rituximab achieved complete remission (CR) 4 weeks post-induction. The 3-year OS rate (88% vs. 63%; P = .35) and the 2-year event-free survival rate (70% vs. 68%; P = .75) were in favor of rituximab. In univariate and multivariate analyses, CR 4 weeks post-induction is recognized as an independent predictor of outcome. However, differences in survival rates did not have a statistical significance.
CD20 expression in adult patients with BCP-ALL seems to be higher in Saudi Arabians than in Caucasians, and it seems to have a tendency towards an inferior outcome in terms of OS. Incorporating rituximab to standard of care seems to improve the outcome in terms of CR, OS, and event-free survival.
Acute lymphoblastic leukemia is more common in children, yet the outcome is much worse in adults than in children. Therefore, factors associated with the poor outcome have to be explored, and answers to improve the outcome have to be found. CD20 marker may contribute to a poor outcome in B-cell acute lymphoblastic leukemia. Rituximab (anti-CD20 antibody) may improve the outcome.