Namık Kemal Tıp Dergisi (Dec 2016)
The Prognostic Significance of Thymidine Kinase Activity Levels In Metastatic Colorectal Cancer
Abstract
Aim:Serum thymidine kinase 1 (TK1) is a sensitive marker of tumor cell proliferation.In this study we aimed to investigate the prognostic significance of serum TK1 activity in metastatic colorectal cancer (MCRC) patients receiving palliative chemotherapy.Materials and Methods: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 patient's clinical 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<0.03, respectively). In multivariate analysis TK1 levels before chemotherapy and weight loss remained as independent prognostic factors ( p=0.001; 0.018, respectively). Patients with TK1 activity level above 65 Du/L and 230 Du/L had a longer PFS (624 vs. 231 days) and OS time respectively (p <0.0001 for each cut off value).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.
