C-C motif chemokine ligand 5 (CCL5) levels in gastric cancer patient sera predict occult peritoneal metastasis and a poorer prognosis

Gastric cancer is one of the most common cancers and the third leading cause of cancer death worldwide. A number of chemokines and cytokines play important roles in the progress of gastric cancer. The roles of C-C motif chemokine ligand 5 (CCL5) in gastric cancer remain unclear. Here, we retrospectively report an analysis of 105 patients with gastric cancer. Increased levels of CCL5 in circulation were correlated with more advanced T and N stages, poorly- or un-differentiated histological types, peritoneal metastasis, higher rates of residual tumor, and shorter survivals. Patients in the CCL5 High Group had stronger CCL5 immunohistochemistry (IHC) staining in tumor beds. Circulating CCL5 concentrations before surgery are a good biomarker for occult peritoneal metastasis. Elevated levels of serum CCL5, along with strong IHC CCL5 staining and poorly- or un-differentiated cancer are predictors for poorer outcomes. In conclusion, increased serum levels of CCL5 can be used to predict peritoneal dissemination and a poorer prognosis.