• Evaluation of the prevalence of symptomatic or asymptomatic deep venous thrombosis in cancer patients with implantable device for central venous access with or without prophylaxis :
  
• Low molecular weight Heparin (LMWH) 2500 U anti-XA/day or Warfarine 1 mg/day during the first line of chemotherapy
  

• - Detection of asymptomatic thrombosis related to implantable device estimated by a systematic echo-doppler. -
  
• - Frequency of other symptomatic venous thromboembolic events between 3 groups.
  
• Comparison of thrombosis prophylaxis by LMWH with warfarin at low dose
  
• -Costs in the 3 strategies
  
• - Tumoral response to chemotherapy in the 3 groups.
  
• - Overall survival in each group.
  

Inclusion Criteria:

• First line chemotherapy for solid tumor with:
• Metastatic disease or
• Involved nodes or
• Unresectable tumor
• Indication for Implantable device for central venous access
• Potential survival > 3 months
• ECOG performance status 0 to 2 (WHO)
• Age between 18 and 75 years.
• Social security guaranteed
• Normal laboratory assessments (platelets> 100000/mm3, TP 60%, spontaneous TCA with M/T<1.5, TGO and TGP < 2xN, serum creatinin<120µmol/l)
• Informed consent signed

Exclusion Criteria:

• Inability to understand informed consent or interfering with compliance for treatment or protocol Anti-coagulant treatment –related criteria
• Acute infectious endocarditis
• History related with heparin allergy or thrombopenia due to heparin
• Uncontrolled high blood pressure (systolic blood pressure >180 mm Hg and/or diastolic blood pressure >110 mm Hg)
• Hemorrhagic syndrome ongoing
• Patient with platelet inhibitors treatment
• Chronic, daily treatment with anti-coagulant therapy (LMWH or AVK), use as preventive or curative level
• Patient with liver failure (TP<60%) or renal insufficiency (creatinin clearance< 20 ml/mn)
• Women with pregnancy and lactating Pathology-related criteria
• deep venous thrombosis history or pulmonary embolism (< 6 months)
• Clinical suspicious of brain metastasis