Please select the eligibility criteria that correspond to the clinical trial below.
Title: ONE WEEK VERSUS FOUR WEEK HEPARIN PROPHYLAXIS IN PATIENTS WITH COLORECTAL CANCER UNDERGOING LAPAROSCOPIC SURGERY: INCIDENCE OF VENOUS THROMBOEMBOLISM AND BLEEDING COMPLICATIONS. THE PRO-LAPS STUDY.
Brief Summary: Overall, only limited evidence exists regarding the clinical benefit of antithrombotic prophylaxis after laparoscopic surgery for cancer. Four studies reported on the incidence of venous thromboembolism (VTE) after laparoscopic surgery for cancer. These studies differ concerning study design, site of cancer, regimens for antithrombotic prophylaxis and reported incidence of VTE.

The aim of this multicenter, randomized study is to assess the clinical benefit of extended (4 weeks) compared to short (one week) heparin prophylaxis after laparoscopic surgery for colorectal cancer.


Options:
A: Inclusion Criteria:

* Confirmed acute symptomatic proximal DVT without symptomatic PE

Exclusion Criteria:

* Legal lower age limitations (country specific)
* Thrombectomy, insertion of a caval filter, or use of a fibrinolytic agent to treat the current episode of DVT and/or PE
* Other indication for VKA than DVT and/or PE
* The pre-randomization anti-coagulant treatment (Criteria # 4) has been prolonged from 36 hours to a maximum of 48 hours.
B: Inclusion criteria:

1. Patients with confirmed symptomatic PE or proximal DVT of the leg(s) who have been treated for 6 to 18 months with therapeutic dosages (intended INR between 2-3) of an oral VKA (e.g. warfarin, acenocoumarol, phenprocoumon, or fluindione) or RE-COVER study medication up to the moment of screening for the current study.
2. Written informed consent

Exclusion criteria:

1. Younger then 18 years of age
2. Indication for VKA other than DVT and/or PE
3. Patients in whom anticoagulant treatment for their index PE or DVT should be continued
4. Active liver disease or liver disease decreasing survival (e.g. acute hepatitis, chronic active hepatitis, cirrhosis) or ALAT \> 3 x ULN
5. Creatinine clearance \< 30 ml/min
6. Acute bacterial endocarditis
7. Active bleeding or high risk for bleeding.
8. Uncontrolled hypertension (investigators judgement)
9. Intake of another experimental drug within the 30 days prior to randomization into the study
10. Life expectancy \<6 months
11. Childbearing potential without proper contraceptive measures\*, pregnancy or breast feeding
C: Inclusion Criteria:

* A histologic diagnosis of malignancy;
* At planned initiation of a new systemic chemotherapy regimen (including patients starting on first chemotherapy or patients previously treated but starting on a new regimen);
* A risk score for VTE ≥3 \[assign score of 2 for very high risk sites of cancer (stomach, pancreas), score of 1 for high risk site (lung, lymphoma, gynecologic, bladder, testicular) and score of 0 for all other sites\], hemoglobin \<10 g/dL or planned use of erythropoiesis stimulating agents, platelet count ≥350,000/mm3, total leukocyte count \> 11,000/mm3 or body mass index ≥ 35 kg/m2\]. Any counts meeting criteria drawn within 2 weeks prior to enrollment are considered acceptable.
* Age 18 years or older
* Provide written, informed consent.

Exclusion Criteria:

* Active bleeding or at high risk of serious bleeding complication in the opinion of the investigator
* Diagnosis of primary brain tumor multiple myeloma, leukemia, or myelodysplastic syndrome
* Planned stem cell transplant
* Life expectancy \< 6 months
* Known allergy to heparin or LMWH
* Patient or caregiver incapable of daily self-injection
* Acute or chronic renal insufficiency with creatinine clearance \< 30 mL/min
* History of heparin-induced thrombocytopenia
* Allergy to contrast agents
* Pregnancy
* Need for anticoagulant therapy
* Platelet count \< 75,000/mm3
D: Inclusion Criteria:

* Consecutive patients who had
* planned laparoscopic surgery for
* colorectal cancer will be included in the study provided no exclusion criteria will be found

Exclusion Criteria:

* age \< 18 years
* surgery for non-cancer disease
* duration of surgery \< 45 min
* other indication for anticoagulant therapy
* known cerebral metastases
* kidney or liver failure
* known hemorrhagic diathesis or high risk for bleeding
* history of intracerebral bleeding or neurosurgery within 6 months, history of heparin induced thrombocytopenia
* pregnancy or lactation
* refusal of informed consent.

Answer: D