The aim of this study is to determine the prevalence of asymptomatic lower extremity DVT detected by US-Doppler and procoagulant microparticles in a selected group of cancer patients suffering from an advanced stage of the disease.

An attempt will be made to determine whether there is a correlation between this prevalence and various clinical and laboratory parameters.

The association between malignancy and venous thromboembolism(VTE) is well known. VTE is one of the most common complications seen in cancer patients Early detection of VTE can identify patients who may benefit from anticoagulant therapy and prevent morbidity and mortality.

There are recommendations for hospitalized cancer patients who are bedridden with an acute medical illness to receive prophylaxis, but in practice this is not clear cut.It has been shown, in other selected groups of patients that Ultrasound Doppler can be used in order to diagnose asymptomatic DVT (deep vein thrombosis). Hematological coagulation tests, including procoagulant microparticles will be performed for the evaluation of coagulation profile, in order to evaluate the possible correlation between the prevalence of asymptomatic DVT and these laboratory parameters.

Inclusion Criteria:

• Cancer patients with an advanced stage of the disease, hospitalized in the oncology department.
• WHO performance status of 3( i.e. spends more than half his/her time in bed or seated) - or 4 ( i.e. completely confined to bed or to chair) : for at least a week; according to the treating physician, the poor performance status results from advanced malignancy.
• Patient is asymptomatic for lower extremity DVT according to the treating physician

Exclusion Criteria:

• major surgery during more than a month, from the time of investigation
• anticoagulant therapy for more than one month, from the time of investigation

patients with an advanced stage of the disease, hospitalized in the oncology department.