14568 Background: Hemostatic activation is known to occur in malignant diseases and this may be associated with tumor progression and angiogenesis. D-dimer levels are elevated in lung, uterine cervix, prostate and colorectal cancer patients. We aimed to evaluate the association and predictive value of LDH and D-Dimer levels with chemotherapy response in metastatic colorectal cancer (MCRC) patients. Patients and Methods: Twenty-five chemotherapy-naive MCRC patients were enrolled into this study. Plasma CEA, CA19–9, D-Dimer and LDH levels were measured before and after 3 cycles of capecitabine + oxaliplatin combination chemotherapy. The comparison between groups were done by Wilcoxon W and Mann-Whitney U tests. Results: Median age was 58 years in 15 female, 10 male patients. All patients received Capecitabine 2,000 mg/m2/day orally on days 1- 14 + Oxaliplatin 130 mg/m2 intravenously on day 1 every 21 days. The chemotherapy response after 3 cycles of treatment were 2 complete response, 7 partial response, 8 stable disease and progressive disease in 8 patients. Plasma CEA, CA19–9, LDH and D-Dimer levels were not significantly different between two groups before chemotherapy (table). Plasma LDH and D-Dimer levels were significantly higher in progressive disease patients than patients with complete, partial or stable response after 3 cycles of chemotherapy, but plasma CEA and CA19–9 were not significantly different between these groups (table). Conclusion: We found that D-dimer and LDH levels dropped in responders while they increased in patients with disease progression. D- Dimer and LDH plasma levels decrease or increase after response and progressive disease, respectively, and can act as a predictive factor of the clinical outcome of the disease. [Table: see text] No significant financial relationships to disclose.
47P Loss-of-function PTPRT and PTPRD mutations predict bevacizumab resistance in metastatic colorectal cancer patients