645 - The Prognostic Significance of Tymidine Kinase Activity Levels in Metastatic Colorectal Cancer

Abstract

ABSTRACT Aim and background Serum thymidine kinase 1 (TK1) is a sensitive marker of tumor cell proliferation. It has been reported as a predictive factor for response rate and disease free survival for hematological and early stage solid organ tumors but its importance as a prognostic factor in metastatic solid organ malignancies is not well studied. In this study we aimed to investigate the prognostic significance of serum TK1 activity in metastatic colorectal cancer (MCRC) patients receiving palliative chemotherapy. Method We prospectively measured serum TK1 activity immediately before the first and second cycle of the treatment in 46 consecutive metastatic MCRC patients. 10 healthy volunteers were also included as a control group. TK1 activity was measured by means of high sensitive non-radioactive DIVITUM assay. The patients' performance status, age, gender, weight loss, hematological and biochemical parameters, serum CEA and CA 19.9 levels and serum TK1 activity levels relation with survival were analyzed. Results The mean TK1 level in the study group was significantly higher than the controls (162.1± 27.8 vs 32.97 ± 7.307; p Conclusion In this study we demonstrated that in the setting of MCRC a significant relation between TK1 levels and survival exists. We consider our results a step further for validation of serum TK1 activity level as an independent prognostic factor in metastatic solid organ tumors. Disclosure All authors have declared no conflicts of interest.