Guidance on treatment-dose low molecular weight heparin for a cancer clot around endoscopy

The gap. The BSG and ESGE guideline on endoscopy in people on antiplatelet or anticoagulant therapy (2021) covers low molecular weight heparin (LMWH) as a bridge while warfarin is stopped: start a therapeutic dose two days after stopping warfarin, give the last dose at least 24 hours before the procedure, restart it the day after. It gives no separate advice for people on long-term treatment-dose LMWH for cancer-associated thrombosis.

Why it matters for cancer. NICE NG158 (2020) recommends considering a direct oral anticoagulant for people with active cancer and a confirmed clot, and LMWH alone or with a vitamin K antagonist if a DOAC is unsuitable (1.3.17, 1.3.18). Its committee found a higher rate of gastrointestinal and genitourinary bleeding with DOACs than with LMWH in active cancer and agreed DOACs may be unsuitable "such as people with gastrointestinal malignancies". So the people steered towards LMWH are disproportionately those having endoscopies for diagnosis, stenting or bleeding.

What is unknown. The timing of the last dose before high-risk procedures, whether a reduced dose should be given in the days around them, and when to restart after polypectomy or sphincterotomy are left to local practice; no study OnCo found compares approaches in this group.