The Assessment of Clinical Usage and Prognostic Value of YKL-40 Serum Levels in Patients With Rectal Cancer Without Distant Metastasis

BACKGROUND: Colorectal cancer is one of the most common and significant malignancies in the world. YKL-40 (chitinase-3-like protein 1) is involved in cell proliferation, migration, inflammation, and tissue remodeling; and serum levels of YKL-40 are associated with patient outcome in various cancers. The aim of this study was to assess the potential clinical usage of YKL-40 pretreatment serum levels as a prognostic biomarker in rectal cancer. METHODS: Concentrations of YKL-40 and standard tumor marker—Carcinoembryonic antigen (CEA)—were assessed in serum of 83 patients with rectal cancer without distant metastasis, and association with clinicopathological characteristics and disease-free and overall survival was evaluated. RESULTS: Concentration of YKL-40 was significantly higher in serum of patients with rectal cancer compared to healthy controls (P = .0001), and YKL-40 levels were able to predict rectal cancer (area under the Receiver Operating Characteristic [ROC] curve = .769) with higher accuracy than CEA (area under the ROC curve = .728) in patients with early stage disease. Increased YKL-40 levels were significantly associated with age (P = .001); however, no association with other clinicopathological characteristics was observed. Finally, in patients with recurrence, the percentage of cases with increased concentration of YKL-40 was significantly higher than in patients without recurrence (P = .041), and Kaplan-Meier analysis demonstrated that elevated YKL-40 concentration is a predictor of poor overall survival in patients with rectal cancer. CONCLUSION: Pretreatment serum levels of YKL-40 may be a novel prognostic factor of overall and disease-free survival in patients with nonmetastatic colorectal cancer.