BACKGROUND: The changes and correlations of TRAIL (TNF-related apoptosis-inducing-ligand) and CXCL8 (IL8) prior to treatment and three months following therapy as well as the corresponding Positron emission tomography (PET/CT) (SUVmax: standardized uptake maximum values) results were evaluated.

MATERIAL AND METHODS: The measurements were taken before and after treatment for comparison purposes. The study population comprised 29 patients with Metastatic Colorectal cancer (MCRC), undergoing PET/CT scanning prior to treatment.

RESULTS: There were significant changes prior to treatment and three months later for sTRAIL (p=0.0080) and CXCL8 (p=0.0001)values. Generally, sTRAIL values were increasing during therapy, while a decrease was observed for CXCL8. Correlation analysis was applied to the data and revealed significant correlations for the SUVmax in the primary tumor prior to treatment and CXCL8 prior to therapy (p=0.0303). Furthermore, significant correlations were observed for the SUVmax and sTRAIL (p=0.0237) as well as CXCL8 (p=0.0002) three months after treatment initiation. CXCL8 prior to treatment was also correlated with the SUV three months after onset of treatment (p=0.0072). A significant correlation was noted for one combination of two variables, the SUVmax in the metastases and CXCL8 prior to treatment (p=0.0175). These results are supported when we group the SUVmax in the metastases following treatment into two groups with SUVmax <5 and SUVmax >5.

CONCLUSIONS: This study provides evidence that proteomics patterns of sTRAIL and CXCL8 predict tumor response und survival in MCRC patients treated with bevacizumab and within a high concordance of FDG-PET/CT findings.

Keywords: Colonic Neoplasms - drug therapy, Antibodies, Monoclonal, Humanized - therapeutic use, Fluorine Radioisotopes - pharmacokinetics, Fluorodeoxyglucose F18 - pharmacokinetics, Interleukin-8 - blood, Positron-Emission Tomography, Proteomics, TNF-Related Apoptosis-Inducing Ligand - blood