Thromboprophylaxis for Patients Undergoing Surgical Resection for Colon Cancer

Inclusion Criteria: * Males or females aged 18 years or older with a pathologically confirmed localized invasive colorectal cancer and no evidence of metastatic disease who are scheduled to undergo surgical resection will be eligible. * All study patients must be enrolled at least two weeks prior to scheduled surgery and provide written informed consent. * All the following criteria must be met to be eligible: 1. Pathological confirmation of an invasive adenocarcinoma of the colon; 2. No evidence of metastatic disease by Computed Tomography (CT) scan of the abdomen and pelvis or chest X-ray (CXR). A Magnetic Resonance Imaging (MRI) of the abdomen and pelvis will be used if the patient has a documented contrast allergy or to verify a questionable finding on the CT scan. Any abnormal findings on CXR will be investigated with a CT scan of the chest. Imaging must be performed within 2 months of randomization; 3. a scheduled surgical operation for resection of the colon cancer; and 4. ECOG performance status 0 or 1. Exclusion Criteria: * Subjects cannot be included in this study if any of the following criteria apply: 1. rectal adenocarcinoma (defined as tumor below the peritoneal reflection or within 12 cm of the anal verge by rigid sigmoidoscopy); 2. prior VTE including deep vein thrombosis (DVT) or pulmonary embolism (PE); 3. requirement for full dose perioperative anticoagulation; 4. requirement for anti-platelet or anti-inflammatory therapy that cannot be discontinued; 5. contraindication to heparin therapy \*\*; 6. geographic inaccessibility (less likely to comply with required follow-up visits and care); 7. participating in another interventional trial that may result in co-intervention or contamination (to be determined by PI); 8. \< 18 years of age; 9. history of other malignancies (except for adequately treated basal or squamous cell carcinoma or carcinoma in situ) within 5 years of the colorectal cancer diagnosis; 10. treatment, including radiation therapy, chemotherapy or targeted therapy, administered for the currently diagnosed colon cancer prior to randomization; 11. pregnant or lactating; and 12. unable/unwilling to providing informed consent.