The association and diagnostic value of red blood cell distribution width in colorectal cancer

Red blood cell distribution width (RDW) is associated with several diseases. However, the diagnostic value of RDW and its related factors remain unclear in colorectal cancer (CRC). This single-center retrospective study evaluated 211 Chinese CRC patients and 103 healthy controls. The association of RDW with the clinical parameters of CRC, as well as its correlations with carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were analyzed. The diagnostic value of RDW alone or combined with CEA and CA19-9 was evaluated using receiver operating characteristic curve analysis. A meta-analysis was also performed to combine our data with previously published data to enhance our findings. In the CRC patients, RDW was clearly elevated and was significantly associated with CRC tumor location, histological type, T status (but not N or M status), and clinical stage. However, RDW was not significantly correlated with CEA or CA19-9 levels. Using RDW to diagnose CRC provided a sensitivity of 53.1% and specificity of 77.7%. The diagnostic accuracy of RDW was enhanced by combining RDW with CEA and CA19-9 levels. We identified 5 previous studies with 633 CRC patients and 1050 controls, which were combined with our cases and controls. The meta-analysis revealed an overall sensitivity of 69%, specificity of 70%, and an area under the curve of 0.74. In CRC cases, RDW was associated with tumor location, histological type, T status, and clinical stage. Furthermore, RDW had a moderate value for diagnosing CRC and might be useful in this setting.