Primary venous thromboembolism prophylaxis in patients with solid tumors: a meta-analysis

Abstract

Venous thromboembolism (VTE) is a leading cause of death among outpatient chemotherapy patients. However the VTE preventive measures for outpatients are not widely advocated. We did a meta-analysis to evaluate the outpatient VTE prevention's effectiveness and safety. We searched electronic databases until the end of December 2012 and reviewed the abstracts and manuscripts following the PRISMA guidelines. Occurrence of first VTE event was the efficacy outcome. The safety end point was major bleeding. We calculated Q statistic and a homogeneity formal test. The odds ratio (OR) estimates were pooled by using the Mantel–Haenszel fixed-effects method in the absence of heterogeneity. Data were analyzed using the R META package). We identified 1,485 articles and reviewed 37 articles based on initial screening. The number of patients included in 11 selected trials was 7,805. The odds of VTE was lower in the prophylaxis group (OR 0.56; 95 % CI 0.45–0.71) and improved when heparin-based prevention was analyzed (OR 0.53; 95 % CI 0.41–0.70). We found strong prevention among patients with lung cancer (OR 0.46; 95 % CI 0.29–0.74) and pancreatic cancer (OR 0.33; 95 % CI 0.16–0.67). Major bleeding events were frequent in the intervention group (OR 1.65; 95 % CI 1.12–2.44). Thromboprophylaxis reduced VTE episodes. The VTE events were reduced by 47 % in heparin-based prophylaxis trials compared to placebo. The patients receiving heparin-based prophylaxis had a 60 % increase in bleeding events. Improving risk stratification tools to personalize prevention strategies may enhance the VTE prevention applicability in cancer patients.

International clinical practice guidelines including guidance for direct oral anticoagulants in the treatment and prophylaxis of venous thromboembolism in patients with cancer

“…The updated search identifi ed eight meta-analyses (1669-9861 patients) [103][104][105][106][107][108][109][110] and six randomised clinical trials [111][112][113][114][115][116] comparing anticoagulant prophylaxis with no intervention or placebo in ambulatory patients receiving systemic anticancer therapy. Overall, a signifi cant 45·0% reduction in VTE occurrence was reported across the six meta-analyses assessing the safety and effi cacy of LMWH compared with no intervention or placebo.…”

“…Overall, a signifi cant 45·0% reduction in VTE occurrence was reported across the six meta-analyses assessing the safety and effi cacy of LMWH compared with no intervention or placebo. [103][104][105][106]108,109 Specifi c cancer subgroup analyses across the meta-analyses showed that LMWH significantly reduced the VTE prevalence compared with no treatment or placebo by 67·9-71·2% in patients with pancreatic cancer (range of 430-748 patients) and by 50·3-53·6% in patients with lung cancer (range of 1926-2075 patients). 103,105 Five of six meta-analyses reported no signifi cant increase in major bleeding with LMWH (13·0-30·0% of patients received LMWH and had major bleeding) compared with no prophylaxis.…”

“…[103][104][105][106]108,109 Specifi c cancer subgroup analyses across the meta-analyses showed that LMWH significantly reduced the VTE prevalence compared with no treatment or placebo by 67·9-71·2% in patients with pancreatic cancer (range of 430-748 patients) and by 50·3-53·6% in patients with lung cancer (range of 1926-2075 patients). 103,105 Five of six meta-analyses reported no signifi cant increase in major bleeding with LMWH (13·0-30·0% of patients received LMWH and had major bleeding) compared with no prophylaxis. The sixth study 105 reported that patients were 65·0% more likely to experience a bleeding event with LMWH (7875 patients in the total population across the 11 studies; OR 1·65, 95% CI 1·12-2·44) compared with no prophylaxis (appendix p 46).…”

“…103,105 Five of six meta-analyses reported no signifi cant increase in major bleeding with LMWH (13·0-30·0% of patients received LMWH and had major bleeding) compared with no prophylaxis. The sixth study 105 reported that patients were 65·0% more likely to experience a bleeding event with LMWH (7875 patients in the total population across the 11 studies; OR 1·65, 95% CI 1·12-2·44) compared with no prophylaxis (appendix p 46). The likelihood of bleeding on LMWH decreased when the analysis was limited to studies with a low risk of bias (41·0% compared with 65·0%), or when the analysis was limited to studies not limited to a single type of cancer (57·0% compared with 65·0%), and these odds ratios were not statistically signifi cant.. Three studies [106][107][108] of 855-6884 patients with cancer assessed bleeding with LMWH versus placebo or no intervention.…”

Primary venous thromboembolism prophylaxis in patients with solid tumors

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Our meta-analysis: ''Primary venous thromboembolism prophylaxis in patients with solid tumors'', was published on line in November 2013 [1]. We are writing to respond to comments made in a letter to the editor referencing our work.

The abstracted and analyzed information in our metaanalysis was obtained independently by 2 reviewers.

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