Inclusion Criteria:

- 1. Diagnosis of pathologically-confirmed invasive adenocarcinoma of the colon 2.
Pre-operative work-up that reveals potential resectability (CT scan or MRI of the abdomen
and pelvis within 90 days of randomization) 3. Pre-operative work-up that reveals no
evidence of metastatic disease (CT scan or MRI of the abdomen and pelvis and chest X-ray
(CXR) or CT scan of the chest within 90 days of randomization) 4. A planned surgical
operation for resection of the colon cancer within 6 weeks from the date of randomization
5. ECOG performance status 0 or 1 6. Age ≥18 years 7. Hemoglobin ≥ 80g/L 8. Able and
willing to sign Research Ethics Board (REB)-approved written consent form 9. Able and
willing to comply with study procedures and follow-up examinations contained within the
written consent form.

Exclusion Criteria:

- 1. Rectal adenocarcinoma (defined as tumour below the peritoneal reflection on imaging
or within 15 cm of the anal verge by rigid sigmoidoscopy) 2. Carcinoma only present in a
completely excised polyp (i.e. no residual tumour evident in the colon) 3. Prior VTE
including deep vein thrombosis (DVT) or pulmonary embolism (PE) 4. Requirement for full
dose peri-operative anticoagulation 5. Contraindication to heparin therapy

1. history of heparin induced thrombocytopenia (HIT)

2. platelet count of less than 100 x 109/L

3. actively bleeding

4. severe hypertension (SBP >200 and/or DBP >120) on more than one reading

5. documented peptic ulcer within 6 weeks

6. severe hepatic failure (INR >1.8)

7. creatinine clearance of < 30 ml/min as calculated by the Cockcroft-Gault formula

8. heparin or pork allergy

9. Other contraindication to anticoagulation 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 sponsor) 8. 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 9. Treatment, including radiation therapy, chemotherapy
or targeted therapy, administered for the currently diagnosed colon cancer prior to
randomization 10. Pregnant or lactating 11. Unable/unwilling to providing informed
consent.