“…Recommendation: There is also no difference in the occurrence of bleeding and increased risk of intraoperative or postoperative bleeding regarding the use of low molecular weight heparin or unfractionated heparin in most evidence extrapolated to patients undergoing general surgery or by abdominal malignancy. Nevertheless, the use of thromboprophylaxis compared with not using heparin perioperatively, may increase postoperative bleeding events 3,13,35,42,43,47,64,72,74,94,95,98,103,105,122 The contraindications for thromboprophylaxis in patients that carry digestive tract surgery -extrapolating to elderly with cancer without surgery -may be particularly hypersensitivity to heparin, septic endocarditis, hemorrhagic stroke, documented bleeding diathesis, treatment with anticoagulant or platelet antiaggregant, and renal or hepatic dysfunction 12,14,15,16,22,31,37,38,42,72,86,95,103. (Recovered = 5806; first selection = 142; included = 13)…”