In summary, this study is aimed at evaluating, for the first time in a prospective manner, the actual incidence of DVT and PE in patients undergoing major lung resections for malignancies. The knowledge gained in this study will be used to inform a future investigation involving a Randomized Controlled Trial (RCT) to compare current post-operative thromboprophylaxis with an extended 30-day prophylaxis protocol with the hope of providing an evidence-based practice change in VTE prophylaxis care for this high risk population.