Potential Diagnostic Value Of Combining Inflammatory Cell Ratios With Carcinoembryonic Antigen For Colorectal Cancer

PURPOSE: To evaluate the diagnostic value of combining the neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR) or lymphocyte–monocyte ratio (LMR) with carcinoembryonic antigen (CEA) in patients with colorectal cancer (CRC). PATIENTS AND METHODS: The diagnostic performance of inflammatory makers and CEA was evaluated in cohort 1 (664 patients with CRC, 336 patients with colorectal polyps and 664 healthy controls) and validated in cohort 2 (87 patients with CRC and 87 healthy controls) by using receiver operating characteristic curve analysis. RESULTS: In cohort 1, the NLR, PLR and CEA levels were significantly higher, while the LMR was markedly lower in patients with CRC than in healthy controls. The PLR and LMR were significantly associated with invasion depth and lymph node metastasis. Moreover, significant differences in the PLR and LMR were observed between patients with stage I/II CRC and healthy or polyp controls and those with stage III/IV CRC. Using the NLR, PLR or LMR with CEA resulted in a significantly larger area under the curve (AUC) than any of them used alone. Combining the PLR and LMR with CEA exhibited the best diagnostic value for CRC (AUC=0.892). The AUCs of this combination were 0.864 and 0.783 for distinguishing stage I/II CRC from healthy and polyp controls, respectively. When we used the same cut-off values to assess the diagnostic ability of these markers in cohort 2, similar results were observed, and the PLR, LMR and CEA combination also showed the highest accuracy (AUC=0.936). CONCLUSION: Combining inflammatory cell ratios with CEA could improve the diagnostic efficacy for CRC patients. The combination of the PLR and LMR with CEA might be a valuable indicator in the early detection and monitoring of CRC patients.