Inclusion criteria All ambulatory cancer patients with clinically suspected DVT. All patients will be managed with the calculation of the Wells score, the measurement of the D-dimer. The presence of DVT will be ascertained by whole-leg ultrasonography performed independently of the results of the Wells and D-dimer. A phone contact/visit at 3 months will verify the development of venous thromboembolic complications in all patients in whom DVT was initially excluded by ultrasonography.