Preoperative serum chemokine (C-C motif) ligand 2 levels and prognosis in colorectal cancer

INTRODUCTION Chemokines are cytokines with chemotactic functions in the initiation and maintenance of immune reactions. They have also been shown to regulate other processes such as cancer progression and cancer cell migration.

OBJECTIVES The aim of this study was to determine the prognostic role of serum levels of chemokine (C-C motif) ligand 2 (CCL2) and chemokine (C-C motif) ligand 5 (CCL5) in patients with colorectal cancer.

PATIENTS AND METHODS The study included a group of 45 patients with colorectal cancer. The serum concentrations of CCL2 and CCL5 were measured preoperatively. Peripheral blood mononuclear cells (PBMC) from patients’ blood were isolated and cultured alone or with cancer cells. The concentrations of chemokines in serum and culture supernatants were measured using the cytometric bead array method. The cut-off points for serum chemokine levels were set based on the receiver-operating characteristic curve analysis at a level of 103.6 pg/ml for CCL2 and of 11933.2 pg/ml for CCL5. The survival analysis and multivariate analysis of prognostic factors were performed.

RESULTS The 5-year survival was 57.5% for the group with low CCL2 levels and 23.87% for the group with high CCL2 levels. For the groups with low and high CCL5 levels, the survival was 18.3% and 49.3%, respectively. For CCL2, the survival of the low-level group was significantly better than that of the highlevel group (P = 0.0028). In the Cox proportional hazard model, radicality of resection (P = 0.001) and CCL2 levels (P = 0.029) were independent prognostic factors.

CONCLUSIONS The serum level of CCL2 in patients with colorectal cancer may have prognostic value. One of the possible mechanisms of CCL2 production is the interaction of PBMC with cancer cells.