Summary
We systematically reviewed the literature to compare the relative efficacy and safety
of extended versus limited duration heparin for perioperative thromboprophylaxis in
patients with cancer. We followed the Cochrane Collaboration systematic review methodology
and searched MEDLINE, EMBASE, ISI the Web of Science, and CENTRAL. The outcomes of
interest included mortality, symptomatic deep venous thrombosis (DVT), pulmonary embolism,
and bleeding. We evaluated the quality of evidence by outcome using the GRADE approach.
Of 3,986 identified citations, we included three randomized clinical trials using
low-molecular-weight heparin (LMWH).The quality of evidence for mortality, DVT, and
major bleeding was low. There was no significant difference between extended (4 weeks)
and limited duration thromboprophylaxis in terms of death at three months (relative
risk [RR]=0.49; 95% confidence interval [CI] 0.12–1.94), or major bleeding at four
weeks (RR=2.94; 95% CI 0.12–71.85).An extended regimen was associated with a significantly
lower risk of asymptomatic DVT (RR=0.21; 95% CI 0.05–0.94). No data was available
for symptomatic DVT. In conclusion, there is limited and low-quality evidence that
extended duration LMWH for perioperative thromboprophylaxis reduces DVT in patients
with cancer undergoing major abdominal or pelvic surgery. More and better quality
evidence is needed to justify extended regimens.
Keywords
Cancer - heparins - surgery - prophylaxis - thrombosis