Serum Chitinase Activity Prognosticates Metastasis of Colorectal Cancer

This study aimed to evaluate the value of chitinase activity in prognosticating the occurrence of metastasis in and prognosis of patients with colorectal cancer (CRC). The chitinase activity in four different groups, namely 335 CRC patients without distant metastasis at their first visit (Group 1), 51 patients with CRC having synchronous liver metastasis (Group 2), 100 healthy age-matched controls (Group 3) and 40 patients with liver cancer (Group 4), were assayed using an enzyme-linked immunosorbent assay. The Cox proportional hazards ratio model and Kaplan–Meier curve were used to identify the association between chitinase activity and the clinical outcome of CRC patients without metastasis in the training set and testing set at their first visit. An in vitro Transwell experiment was performed to evaluate the migration of colon cancer cells. Patients with high chitinase activity had a significantly higher metastasis risk than those with low chitinase activity in the training and testing sets during follow-up, both at stage I/II and stage III. Further, multivariate analysis revealed that chitinase activity was an independent risk factor prognosticating liver metastases (P = 0.001). The combination of chitinase activity and lymph node metastasis status increased the accuracy of the prognosis of liver metastases after radical resection (P = 0.454E-011). In addition, chitinase promoted CRC cell migration in vitro. Chitinase activity can prognosticate the occurrence of metastasis in patients with CRC. Moreover, the combination of chitinase activity and N stage increased the power of prognosticating the occurrence of metastasis. Inhibiting chitinase activity may serve as a new strategy to treat metastases of CRC.