Plasma YKL-40: a Potential Biomarker for Tumor Invasion in Esophageal Cancer

Background: YKL-40, a chitinase-like glycoprotein has been identified as a candidate tumor marker. The current study evaluated the clinical significance of plasma YKL-40 in esophageal cancer patients. Methods: We enrolled 127 esophageal cancer patients, 29 healthy controls. Plasma YKL-40 levels were measured through enzyme linked immunosorbent assay. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic efficiency of plasma YKL-40 in esophageal cancer patients. The correlations between plasma YKL-40 and clinicopathological characteristics of esophageal were analyzed. Results: Plasma YKL-40 levels were significantly higher in patients with lymph node metastasis than those that were non-metastatic (p = 0.005). Patients with tumor thrombus formation presented with significantly higher YKL-40 levels than those without thrombus formation (160.3 vs. 74.7 ng/mL, p = 0.012). YKL-40 levels in patients with advanced stage (III and IV) were significantly higher than those in the early stages (I and II, p = 0.016). ROC curve analysis showed that the area under curve was 0.909, and the best diagnostic threshold of YKL-40 for esophageal cancer was 80.6 ng/mL with 68.9% sensitivity and 96.6% specificity. Conclusions: This study indicated that YKL-40 may be a biomarker for esophageal cancer and potential biomarker for identification of invasive esophageal cancer.