Red Blood Cell Distribution Width (RDW): Useful Predictor for Treatment Response in Metastatic Colorectal Cancer

Introduction: Red cell distribution width (RDW) is a widely used labora？tory parameter for the quantification of the extent of eryth？rocyte anisocytosis, which reflects the variability of the size of the circulating erythrocytes. Despite the fact that cancer is widely accepted to both as a cause and as a result of chronic inflammation, RDW elevation has scarcely been investigated as a potential biomarker of solid cancer activity. Our study is the first systemat？ic one to evaluate whether RDW elevation may have a potential role as a biomarker of colorectal cancer activity. Method: A retrospective analysis was conducted in patients with primary diagnosed or recurrent metastatic disease between January 2008 and August 2017. The exclusion criteria of the study were the presence of medical history of other malignancy, pregnancy, kidney transplantation, hematological disorders, severe anemia, infectious or inflammatory disease, iron supplementation therapy, recent venous thrombosis (past 6 months), recent blood transfusion (past 3 months), chronic obstructive pulmonary disease, hepatitis B or C, heart failure, arrhythmia, untreated thyroid disease, and severe liver and/or renal insufficiency as described previously. Results: The mean RDW value of the metastatic colorectal cancer patient was 15.95, compared with 13.5 in normal population. The RDW values were same in patients at the high risk of progression and low risk of progression. The median overall survival at patients have RDW ≤15 were 42.5 mounths, patients RDW>15 were 26.3. There is no statically difference in two groups. Discussion: RDW is found in the standard complete blood count, it does not bring any extra costs and it can be easily evaluated, which strengthens the fact that it can used as a biomarker in the early detection of cancer. Based on the findings of the current study, we recommend that RDW, a very common, easy, and simple marker, should be considered for treatment planning and follow-up of colorectal cancer patients