Enoxaparin Versus Placebo for Venous Thromboembolism Prevention in Low Risk Cancer Patients After Surgical Procedures: a Randomized, Double Blind, Placebo Controlled Clinical Trial Pilot Study

The five most common cancers in the United States, based on National Cancer Institute data, include breast, lung, urologic (prostate and bladder), colorectal, and melanoma. As such, we will conduct our work in these patient populations to make our results as generalizable as possible. Inclusion criteria will include: * Adult (age≥18) patients * Surgical procedure under general anesthesia * Caprini score ≤6 * Expected post-operative stay will be at least 23 hours (these are the patients for whom current guidelines mandate provision of chemical prophylaxis, but for whom current clinical practice demonstrates equipoise.) Exclusion criteria will include: * Contraindication to use of enoxaparin * Intracranial bleeding/stroke * Hematoma or bleeding disorder * Heparin-induced thrombocytopenia positive * Creatinine clearance ≤ 30mL/min * Serum creatinine \>1.6mg/dL * Planned epidural anesthesia * Scheduled return to the operating room within 90 days will be a criteria for exclusion-we will only consent patients for whom a single operative procedure is scheduled to avoid interruption of post-operative anticoagulation or placebo for a second operative procedure * Patients with platelet count \<50k/uL will be excluded only with "a positive in vitro test for anti-platelet antibody in the presence of enoxaparin sodium," per the enoxaparin package insert.