Table 4.

Guideline recommendations for thromboprophylaxis in patients undergoing cancer surgery

Guideline	Recommendations
American Society of Clinical Oncology 2020	All patients undergoing major surgery should be offered pharmacological prophylaxis with UFH or LMWH unless contraindicated. (Recommendation type: evidence‐based; evidence quality: high; strength of recommendation: strong.) Prophylaxis should be commenced preoperatively. (Recommendation type: evidence based; evidence quality: intermediate; strength of evidence: moderate.) Mechanical prophylaxis should not be used as monotherapy unless pharmacologic prophylaxis contraindicated. (Recommendation type: evidence based; evidence quality: intermediate; strength of recommendation: strong.) Combined pharmacologic/mechanical prophylaxis may improve efficacy, especially in highest‐risk patients. (Recommendation type: evidence based; evidence quality: intermediate; strength of recommendation: moderate.) Pharmacologic prophylaxis should be continued for at least 7–10 days. Extended prophylaxis with LMWH for up to 4 weeks postoperatively is recommended for patients undergoing major open or laparoscopic abdominal or pelvic cancer surgery with high‐risk features (restricted mobility, obesity, history of VTE, or additional risk factors). In lower‐risk surgical settings, the decision on appropriate duration of thromboprophylaxis should be made on a case‐by‐case basis. (Recommendation type: evidence based; evidence quality: high; strength of recommendation: moderate to strong.)
International Initiative on Thrombosis and Cancer 2019	LMWH (if CrCl ≥30 mL/min) once daily or low‐dose UFH three times a day is recommended. Pharmacologic prophylaxis should be started 2–12 hours preoperatively and continued for at least 7–10 days. No data to suggest one LMWH superior to another (grade 1A). Values and preferences: Once‐daily LMWH more convenient. Insufficient evidence to support fondaparinux as an alternative to LMWH (grade 2C). Values and preferences: Same as above. Use of highest prophylactic dose of LMWH is recommended (grade 1A). Values and preferences: Same as above. Extended prophylaxis (4 weeks) with LMWH to prevent postoperative VTE after major laparotomy (grade 1A) and laparoscopic surgery (grade 2C) is indicated in patients with a high VTE risk and low bleeding risk. Values and preferences: Daily injections for longer duration. Costs: The price of LMWH may influence choice. Mechanical thromboprophylaxis is not recommended as monotherapy, except when pharmacologic prophylaxis is contraindicated (grade 2B). Values and preferences: No injections. IVC filters are not recommended for routine prophylaxis (grade 1A).
National Comprehensive Cancer Network 2020	Prophylactic dose LMWH, UFH, or fondaparinux with or without PCD is recommended (category 1). Consider preoperative dosing with UFH or LMWH for high‐risk surgery patients with or without PCD (category 2A). If anticoagulant prophylaxis is contraindicated, mechanical prophylaxis is recommended (category 2A). Out‐of‐hospital VTE prophylaxis is recommended for up to 4 weeks postsurgery for high‐risk patients with abdominal or pelvic cancer (category 2A).
Spanish Society of Medical Oncology 2018	In the absence of contraindications, all patients undergoing major surgery should receive pharmacologic thromboprophylaxis (grade 1A). LMWH are the preferred agents. Prophylaxis should be initiated preoperatively or as soon as possible postoperatively. Mechanical prophylaxis can be added to pharmacologic prophylaxis in high‐risk patients but should not be used as monotherapy unless pharmacologic prophylaxis is contraindicated (grade 2C). Patients should receive at least 7–10 days of prophylaxis, and high‐risk patients undergoing major abdominal or pelvic cancer surgery should be considered for extended thromboprophylaxis for 4 weeks (grade 1A). We suggest the same recommendation for laparoscopic surgery; risk factors and the duration and type of procedure must be assessed (grade 2C).

Abbreviations: CrCl, creatinine clearance; IVC, inferior vena cava; LMWH, low‐molecular‐weight heparin; PCD, pneumatic compression device; UFH, unfractionated heparin; VTE, venous thromboembolism.