Abstract Objective: SF is a complex coupling fibrin monomer and fibrinogen molecules to be formed in the early-activated state of blood coagulation. The level of SF reflects the thrombin generation activity in plasma. There is increasing evidence that SFMC is expected to serve as a parameter for thrombus formation and DIC, in particular its early stage. Thrombin generation is activated in the metastasis of malignant neoplasm, The aim of this study is to determine whether the SF could be a new marker for the metastasis of malignant neoplasm. Material and Methods: From 2007 to 2008, a total of 86 patients who underwent radical surgery for treatment to the cancer of digestive organs (including cancer of esophagus, stomach, colon, rectum, liver, biliary tract, and pancreas) were enrolled in this study. We measured SF together with established tumor markers before the surgery and every three months after the surgery. Each of them was compared with imaging tests such as CT scan, ultrasounds, MRI, PET-CT, GIF, and CF. Results: There were not admitted the rise of SF neither before nor after surgery in the case of stage1 and 2. No metastasis was admitted with the imaging tests in the cases of stage1 and 2, either. In the cases of stage3 and 4, there were some cases with the rise of SF before the surgery. The decrease of SF and tumor markers were admitted in the cases of excising the radical cure. SF was not high in the some cases with relapse or metastasis which condition was considered to be suppressed by chemotherapy and radiotherapy. Moreover, the rise of SF was admitted in all samples in the case of multiple liver metastasis and multiple peritoneal dissemination. Conclusions: Though this study suggests that SF could be a parameter for the condition of metastatic malignant neoplasm, it has not been systematically studied whether SF is useful for early detection of metastasis and relapse or not. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 881.