Coagulation in Colorectal cancer.

Rationale:
Cancer patients who develop a venous thrombotic event have a worse prognosis compared to patients without thrombosis. There is evidence that activation of the coagulation cascade increases tumor growth and angiogenesis.

Objective:
To find a marker linked to angiogenesis and coagulation to predict prognosis in cancer patients.

Study design:
Multicenter prospective cohort study.

Study population:
colorectal cancer patients, all disease stages.

Main study parameters/endpoints:

Primary Objective: the association between tissue factor positive microparticles level in colorectal cancer patients and time to progressive disease.

Secondary Objectives:

1. The association between the other chosen markers ( thrombomodulin, von Willebrand factor, VEGF, Tissue factor, cancer procoagulant, thrombin generation, PAI-1, PAP complex, CRP, d-dimer, P-selectin, thrombospondin-1) and time to progressive disease;

2. The association between the chosen markers and the occurrence of a VTE;

3. The association between the chosen markers and disease stage;

4. The association between the chosen markers and the use of chemotherapy;

5. The association between the chosen markers and the use of bevacizumab.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness:
In colorectal cancer patients extra blood will be sampled. In every venous puncture 25 ml extra blood will be sampled. There is no need for extra visits or patient questionnaires. Therefore there is no extra risk expected with a minimum of burden. Also already excised tumor tissue will be examined. Extra blood sampling will occur depending on treatment schedule for a minimum of two times to a maximum of six times.

Cancer patients who develop thrombosis have a worse prognosis than cancer patinets without thrombosis. There is evidence that activation of the coagulation cascade increases tumor growth and angiogenesis. Therefore the objective is to find a marker in blood linked to angiogenesis and coagulation to predict the prognosis in cancer patients.

Blood will be sampled at specific points in treatment and in case of progressive disease and thrombosis. Patients will be followed two years.

N/A, observational study.