Abstract
To evaluate the diagnostic performance of combined biomarkers for colorectal cancer (CRC), this prospective observational study enrolled 188 CRC patients and 693 non-CRC controls from Hunan Provincial People's Hospital. Binary logistic regression was used to establish a predictive model for CRC risk factors, and receiver operating characteristic (ROC) curve analysis was performed to assess diagnostic efficacy. Results showed that the positive rates of plasma methylated SEPT9 (mSEPT9) and fecal occult blood test (FOBT) in the CRC group were significantly higher than those in the non-CRC group (both P < 0.001). Additionally, levels of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), red blood cell distribution width-coefficient of variation (RDW-CV), red blood cell distribution width-standard deviation (RDW-SD), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were markedly elevated in CRC patients (all P < 0.001). Multivariate regression identified mSEPT9, CEA, CA19-9, FOBT, RDW-CV, and PLR as independent CRC-related factors. Notably, their combined model achieved an area under the curve (AUC) of 0.939, with a sensitivity of 0.920 and specificity of 0.839, offering a valuable non-invasive strategy to enhance CRC diagnosis.