CLINICAL SIGNIFICANCE OF SERUM HEPATOCYTE GROWTH FACTOR (HGF) AND ITS RECEPTOR CMET LEVELS IN COLORECTAL CANCER PATIENTS

Objective: The cMET receptor tyrosine kinase and its ligand hepatocyte growth factor (HGF) regulate many signaling pathways involved in proliferation and cell motility, invasion and angiogenesis. Deregulation of HGF/cMET system by different biological mechanisms may contribute to the minor development in many types of cancers. Therefore, the present study was performed to investigate clinical significance of serum patterns of both HGF and cMET in colorectal cancer (CRC) patients. Materials and methods: One hundred and three CRC patients were enrolled in this study. Serum HGF and cMET levels were measured by the solid-phase sandwich enzyme-linked immunosorbent assay (ELISA) method. Age- and sex-matched 30 healthy control patients were included in the analysis. Results: The median age of the patients was 60 years old, range 24 to 84 years. Most of the tumor localization areas were colon (n = 57, 55%). Median follow-up time was 14 months. While thirty-one patients (30 %) experienced disease progression, twenty-three of the remaining patients (22 %) died because of the disease. The estimated 2-year overall (OS) and 1-year progression-free survival (PFS) rates for the whole patient groups were 70.1 % (95% confidence interval (CI) = 57.2-83.0) and 233 % (95% CI = 82-38.4), respectively. The baseline median serum HGF and cMET levels were significantly higher in metastatic CRC patients than in the healthy control group (p<0.001). Furthermore, worse performance status and metastatic disease were associated with higher serum HGF concentrations all patients with CRC (p=0.03 and p=0.03, respectively). Clinical variables including metastatic disease, greater pathologic tumor status, and colonic site were found to be correlated with higher serum cMET concentrations all patients with CRC (p=0.01, p=0.05, and p=0.04, respectively). A correlation was determined between HGF and cMET levels in metastatic CRC patients (rs=0.286, n=47, and p=0.05), (Spearman's correlation). Our study results did not show a statistically significant serum HGF and cMET concentrations regarding PFS and OS. Conclusion: Serum levels of HGF and cMET may be diagnostic markers in CRC patients. However; their predictive and prognostic values were not determined.