The Importance of Tyrosine Kinase-Like Orphan Receptor 1 (ROR-1) in Chronic Lymphocytic Leukemia

Type 1 tyrosine kinase-like orphan receptor (ROR-1) is expressed on neoplastic B cell surface in chronic lymphocytic leukemia (CLL). In this study, we aimed to determine the prognostic significance of ROR-1 expression with relationship of clinical features and therapy requirements. Retrospectively, we analyzed the medical records of CLL patients who diagnosed at Hematology department between December 2016 and October 2019. The following panel 8 color combinations of monoclonal antibodies. While matutes scoring was accepted to indicate cell surface expression of 30% or greater, we practiced to determine its cut-off value with a ROC (receiver operating characteristic) curve. The optimal ROR-1 cut-off was evaluated 80.5%. White blood cell count, lymphocyte count and platelet count were found significantly higher in patients with ROR-1 level > 80.5% at diagnosis (p<0.05). Furthermore, the majority of patients with ROR-1 level > 80.5% were presented with splenomegaly initially. Rates of therapy requirements was found similar in two groups. Higher higher level and uniform expression of ROR-1 may be used as a diagnostic marker rather than predictive or prognostic marker in CLL patients. Therefore, we suggest that ROR1 adding in routine antibody panels may be useful at diagnosis of CLL.