The prognostic value of CXCR4 and pCXCR4 in B-lineage acute lymphoblastic leukemia in adults

Background CXC chemokine receptor 4 (CXCR4) is activated by phosphorylation (pCXCR4) and is essential for the migration of hematopoietic precursors to bone marrow. Data regarding the prognostic impact of CXCR4 in patients with B-acute lymphoblastic leukemia (B-ALL) are sparse and limited to the pediatric population. Patients and methods Fifty adult patients with B-ALL were included in the study. CXCR4 was assessed by flow cytometry and pCXCR4 by immunocytochemistry. All patients received a hyper-CVAD regimen. Results Thirty-one patients had positive CXCR4 expression, of whom only 18 (58%) had positive pCXCR4 expression. The complete response rate for patients with positive expression of pCXCR4 was significantly inferior to those with negative expression (61.1 vs. 93.7%; P 0.01). In the multivariate analysis, pCXCR4 expression was associated with a worse disease-free survival ( P 0.027) and overall survival (P 0.024). Positive expression of pCXCR4 was not associated with an increased incidence of extramedullary disease or had any relation to the degree of maturity of B-ALL. Conclusion The current study indicates that adult B-ALL patients with positive expression of pCXCR4 have an inferior response to chemotherapy, disease-free survival, and overall survival compared with patients with negative expression.