A systematic review 1 including 24 RCTs with a total of 5 933 cancer patients undergoing surgery was abstracted in DARE. The trials used fibrinogen uptake test (FUT), venography or ultrasound as detection methods for deep venous thrombosis. The overall DVT rate was lowest among patients who received heparin prophylaxis (low dose unfractionated heparin [LDUH] [defined as anything below 5 000 units three times daily] or low molecular weight heparin [LMWH], high [defined as >3 400 units daily] or low dose ) plus mechanical prophylaxis (5%), compared with patients who received heparin prophylaxis alone (LDUH or LMWH) (12.7%) or no prophylaxis (35.2%). Based of 17 studies using FUT, there was no significant difference in DVT rates between groups receiving LDUH compared with LMWH (p>0.05). Rates of DVT were significantly lower for patients receiving high-dose LMWH compared with low-dose LMWH (7.9% versus 14.5%, p<0.0001). In terms of minor complications (7 studies, n=2 114), major complications (7 studies, n=2 083) or discontinuation rates in high-dose regimens (4 studies, n=1 668), there were no significant differences (p>0.05) between LDUH and LMWH groups.
Comment: The quality of evidence is downgraded by limitations in review quality (limited search, incomplete reporting of review methods; no testing for heterogeneity, questionable pooling).
Primary/Secondary Keywords