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Background: Oral anticoagulants may improve the survival of people with cancer through both an antitumor effect and antithrombotic effect, yet increase the risk of bleeding., Objectives: To evaluate the efficacy and safety of oral anticoagulants in ambulatory people with cancer undergoing chemotherapy, hormonal therapy, immunotherapy or radiotherapy, but otherwise have no standard therapeutic or prophylactic indication for anticoagulation., Search Methods: We conducted a comprehensive literature search in February 2016 that included a major electronic search of Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 1), MEDLINE (Ovid) and Embase (Ovid); handsearching of conference proceedings; checking of references of included studies; a search for ongoing studies; and using the 'related citation' feature in PubMed. As part of the living systematic review approach, we are running continual searches and will incorporate new evidence rapidly after it is identified. This update of the systematic review is based on the findings of a literature search conducted on 14 December 2017., Selection Criteria: Randomized controlled trials (RCTs) assessing the benefits and harms of vitamin K antagonist (VKA) or direct oral anticoagulants (DOAC) in ambulatory people with cancer. These participants are typically undergoing systemic anticancer therapy, possibly including chemotherapy, target therapy, immunotherapy or radiotherapy, but otherwise have no standard therapeutic or prophylactic indication for anticoagulation., Data Collection and Analysis: Using a standardized form, we extracted data in duplicate on study design, participants, intervention outcomes of interest and risk of bias. Outcomes of interest included all-cause mortality, symptomatic venous thromboembolism (VTE), symptomatic deep vein thrombosis (DVT), pulmonary embolism (PE), major bleeding, minor bleeding and health-related quality of life (HRQoL). We assessed the certainty of evidence for each outcome using the GRADE approach (GRADE Handbook)., Main Results: Of 8545 identified citations, including 7668 unique citations, 16 papers reporting on 7 RCTs fulfilled the inclusion criteria. These trials enrolled 1486 participants. The oral anticoagulant was warfarin in six of these RCTs and apixaban in the seventh RCT. The comparator was either placebo or no intervention. The meta-analysis of the studies comparing VKA to no VKA did not rule out a clinically significant increase or decrease in mortality at one year (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.87 to 1.03; risk difference (RD) 29 fewer per 1000, 95% CI 75 fewer to 17 more; moderate certainty evidence). One study assessed the effect of VKA on thrombotic outcomes. The study did not rule out a clinically significant increase or decrease in PE when comparing VKA to no VKA (RR 1.05, 95% CI 0.07 to 16.58; RD 0 fewer per 1000, 95% CI 6 fewer to 98 more; very low certainty evidence), but found that VKA compared to no VKA likely decreases the incidence of DVT (RR 0.08, 95% CI 0.00 to 1.42; RD 35 fewer per 1000, 95% CI 38 fewer to 16 more; low certainty evidence). VKA increased both major bleeding (RR 2.93, 95% CI 1.86 to 4.62; RD 107 more per 1000, 95% CI 48 more to 201 more; moderate certainty evidence) and minor bleeding (RR 3.14, 95% CI 1.85 to 5.32; RD 167 more per 1000, 95% CI 66 more to 337 more; moderate certainty evidence).The study assessing the effect of DOAC compared to no DOAC did not rule out a clinically significant increase or decrease in mortality at three months (RR 0.24, 95% CI 0.02 to 2.56; RD 51 fewer per 1000, 95% CI 65 fewer to 104 more; low certainty evidence), PE (RR 0.16, 95% CI 0.01 to 3.91; RD 28 fewer per 1000, 95% CI 33 fewer to 97 more; low certainty evidence), symptomatic DVT (RR 0.07, 95% CI 0.00 to 1.32; RD 93 fewer per 1000, 95% CI 100 fewer to 32 more; low certainty evidence), major bleeding (RR 0.16, 95% CI 0.01 to 3.91; RD 28 fewer per 1000, 95% CI 33 fewer to 97 more; low certainty evidence); and minor bleeding (RR 4.43, 95% CI 0.25 to 79.68; RD 0 fewer per 1000, 95% CI 0 fewer to 8 more; low certainty evidence)., Authors' Conclusions: The existing evidence does not show a mortality benefit from oral anticoagulation in people with cancer but suggests an increased risk for bleeding.Editorial note: this is a living systematic review. Living systematic reviews offer a new approach to review updating in which the review is continually updated, incorporating relevant new evidence, as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Background: Several basic research and clinical studies have led to the hypothesis that oral anticoagulants may improve the survival of patients with cancer through an antitumor effect in addition to their antithrombotic effect., Objectives: To evaluate the efficacy and safety of oral anticoagulants in patients with cancer with no therapeutic or prophylactic indication for anticoagulation., Search Methods: We performed a comprehensive search for studies of anticoagulation in patients with cancer including 1. a February 2013 electronic search of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE; 2. a handsearch of the American Society of Clinical Oncology (starting with its first volume, 1982) and of the American Society of Hematology (starting with the 2003 issue); 3. checking of references of included studies; 4. use of the 'related citation' feature in PubMed; and 5. searching clinical trials.gov for ongoing studies., Selection Criteria: Randomized controlled trials (RCTs) comparing vitamin K antagonist or other oral anticoagulants with no intervention or placebo in patients with cancer without clinical evidence of venous thromboembolism., Data Collection and Analysis: Using a standardized data form, we extracted data on risk of bias, participants, interventions and outcomes of interest that included all-cause mortality, venous thromboembolism, major bleeding, and minor bleeding., Main Results: Of 9559 identified citations, seven RCTs (eight reports) fulfilled the inclusion criteria. The oral anticoagulant was warfarin in six of these RCTs and apixaban in the seventh RCT. The comparator was either placebo or no intervention. The use of warfarin had no effect on mortality at six months (risk ratio (RR) 0.98; 95% confidence interval (CI) 0.82 to 1.22), one year (RR 0.97; 95% CI 0.89 to 1.04), two years (RR 0.98; 95% CI 0.81 to 1.18), or five years (RR 0.92; 95% CI 0.83 to 1.01). One study assessed the effect of warfarin on venous thromboembolism and did not show or exclude a beneficial or detrimental of effect (RR 0.15; 95% CI 0.02 to 1.20). Warfarin increased both major bleeding (RR 4.24; 95% CI 1.86 to 9.65) and minor bleeding (RR 3.19; 95% CI 1.83 to 5.55). We judged the quality of evidence as moderate for all outcomes.The study assessing the effect of apixaban did not show or exclude a beneficial effect or detrimental of apixaban on mortality at six months (RR 0.16; 95% CI 0.01 to 1.66); major bleeding (RR 0.62; 95% CI 0.06 to 6.63); and minor bleeding (RR 2.87; 95% CI 0.16 to 51.82). We judged the quality of evidence as low for all outcomes., Authors' Conclusions: Existing evidence does not suggest a mortality benefit from oral anticoagulation in patients with cancer while the risk for bleeding is increased.

Background: A number of basic research and clinical studies have led to the hypothesis that oral anticoagulants may improve the survival of patients with cancer through an antitumor effect in addition to their antithrombotic effect., Objectives: To evaluate the efficacy and safety of oral anticoagulants in patients with cancer with no therapeutic or prophylactic indication for anticoagulation., Search Strategy: A comprehensive search for studies of anticoagulation in cancer patients including (1) a February 2010 electronic search of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE, EMBASE, ISI the Web of Science; (2) hand search of the American Society of Clinical Oncology (starting with its first volume, 1982) and of the American Society of Hematology (starting with its 2003 issue); (3) checking of references of included studies; and (4) use of "related article" feature in PubMed., Selection Criteria: Randomized controlled trials (RCTs) comparing vitamin K antagonist or other oral anticoagulants to no intervention or placebo in cancer patients without clinical evidence of venous thromboembolism., Data Collection and Analysis: Using a standardized data form we extracted data on risk of bias, participants, interventions and outcomes of interest that included all cause mortality, venous thromboembolism, major bleeding and minor bleeding., Main Results: Of 8187 identified citations, five RCTs fulfilled the inclusion criteria. Warfarin was the oral anticoagulant in all of these RCTs and it was compared to either placebo or no intervention. The quality of evidence was moderate for all outcomes. The effect of warfarin on reduction in mortality was not statistically significant at six months (Relative risk (RR) = 0.96; 95% CI 0.80 to 1.16), at one year (RR = 0.94; 95% CI 0.8 to 1.03) at two years (RR = 0.97; 95% CI 0.87 to 1.08) or at five years (RR 0.91; 95% CI 0.83 to 1.01). One study assessed the effect of warfarin on venous thromboembolism and showed a RR reduction of 85% (P = 0.031). Warfarin increased both major bleeding (RR = 4.24; 95% CI 1.85 to 9.68) and minor bleeding (RR = 3.34; 95% CI 1.66 to 6.74)., Authors' Conclusions: Existing evidence does not suggest a mortality benefit from oral anticoagulation in patients with cancer while increasing the risk for bleeding.

Background: A number of basic research and clinical studies have led to the hypothesis that oral anticoagulants may improve the survival of patients with cancer through an antitumor effect in addition to their antithrombotic effect., Objectives: To evaluate the efficacy and safety of oral anticoagulants in patients with cancer with no therapeutic or prophylactic indication for anticoagulation., Search Strategy: A comprehensive search for studies of anticoagulation in cancer patients including (1) a February 2010 electronic search of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE, EMBASE, ISI the Web of Science; (2) hand search of the American Society of Clinical Oncology (starting with its first volume, 1982) and of the American Society of Hematology (starting with its 2003 issue); (3) checking of references of included studies; and (4) use of "related article" feature in PubMed., Selection Criteria: Randomized controlled trials (RCTs) comparing vitamin K antagonist or other oral anticoagulants to no intervention or placebo in cancer patients without clinical evidence of venous thromboembolism., Data Collection and Analysis: Using a standardized data form we extracted data on risk of bias, participants, interventions and outcomes of interest that included all cause mortality, venous thromboembolism, major bleeding and minor bleeding., Main Results: Of 8187 identified citations, five RCTs fulfilled the inclusion criteria. Warfarin was the oral anticoagulant in all of these RCTs and it was compared to either placebo or no intervention. The quality of evidence was moderate for all outcomes. The effect of warfarin on reduction in mortality was not statistically significant at six months (Relative risk (RR) = 0.96; 95% CI 0.80 to 1.16), at one year (RR = 0.94; 95% CI 0.8 to 1.03) at two years (RR = 0.97; 95% CI 0.87 to 1.08) or at five years (RR 0.91; 95% CI 0.83 to 1.01). One study assessed the effect of warfarin on venous thromboembolism and showed a RR reduction of 85% (P = 0.031). Warfarin increased both major bleeding (RR = 4.24; 95% CI 1.85 to 9.68) and minor bleeding (RR = 3.34; 95% CI 1.66 to 6.74)., Authors' Conclusions: Existing evidence does not suggest a mortality benefit from oral anticoagulation in patients with cancer while increasing the risk for bleeding.

To evaluate the effectiveness and safety of oral anticoagulants in improving survival of cancer patients. We conducted in January 2007 a comprehensive search for relevant randomized clinical trials (RCTs). We extracted data on methodological quality, participants, interventions and outcomes using a standardized form. Five RCTs fulfilled the inclusion criteria and all compared warfarin to either placebo or no intervention. Their overall methodological quality was acceptable. The effect of warfarin on mortality was not statistically significant at 6 months (RR = 0.96; 95% CI 0.80-1.16), at 1 year (RR = 0.95; 95% CI 0.86-1.05), at 2 years (RR = 0.97; 95% CI 0.87-1.08) or at 5 years (RR 0.91; 95% CI 0.83-1.01). In the subgroup of patients with small cell lung cancer (SCLC), warfarin reduced mortality at 6 months (RR = 0.69; 95% CI 0.50-0.96) but not at 1 year (RR = 0.88; 95% CI 0.77-1.01). This 6 months mortality benefit was statistically significant in the subgroup of extensive SCLC (RR = 0.65; 95% CI 0.45-0.93) but not in the subgroup of limited SCLC (RR = 0.68; 95% CI 0.36-1.28). Warfarin increased both major bleeding (RR = 4.24; 95% CI 1.85-9.68) and minor bleeding (RR = 3.34; 95% CI 1.66-6.74). The evidence suggests a survival benefit from warfarin in patients with extensive SCLC, but not in other patient groups. This survival benefit should be weighed against the increased risk for hemorrhage.

Background: A number of basic research and clinical studies have led to the hypothesis that oral anticoagulants may improve the survival of patients with cancer through an antitumour effect in addition to their antithrombotic effect., Objectives: To evaluate the effectiveness and safety of oral anticoagulation (including vitamin K antagonists and ximelagatran) as an intervention to improve survival of patients with cancer., Search Strategy: A comprehensive search for studies of anticoagulation in cancer patients including (1) a January 2007 electronic search of the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, ISI the Web of Science; (2) hand search of the American Society of Clinical Oncology (starting with its first volume, 1982) and of the American Society of Hematology (starting with its 2003 issue); (3) checking of references of included studies; and (4) use of "related article" feature in PubMed., Selection Criteria: Randomized clinical trials (RCTs) comparing vitamin K antagonist or ximelagatran to no intervention or placebo in cancer patients without clinical evidence of venous thromboembolism., Data Collection and Analysis: Using a standardized data form we extracted data on methodological quality, participants, interventions and outcome of interest that included all cause mortality, symptomatic deep venous thrombosis, symptomatic pulmonary embolism, major bleeding and minor bleeding., Main Results: Of 3986 identified citations five RCTs fulfilled the inclusion criteria. Warfarin was the oral anticoagulant in all of these RCTs and it was compared to either placebo or no intervention. The overall methodological quality of these RCTs was acceptable. The effect of warfarin on reduction in mortality was not statistically significant at six months (Relative risk (RR) = 0.96; 95% CI 0.80 to 1.16), at one year (RR = 0.95; 95% CI 0.86 to 1.05) at 2 years (RR = 0.97; 95% CI 0.87 to 1.08) or at five years (RR 0.91; 95% CI 0.83 to 1.01). In the subgroup of patients with small cell lung cancer (SCLC), warfarin reduced mortality at six months (RR = 0.69; 95% CI 0.50 to 0.96) but not at one year (RR = 0.88; 95% CI 0.77 to 1.01). This six month mortality benefit was statistically significant in the subgroup of extensive SCLC (RR = 0.65; 95% CI 0.45 to 0.93) but not in the subgroup of limited SCLC (RR = 0.68; 95% CI 0.36 to 1.28). One study assessed the effect of warfarin on venous thromboembolism and showed a RR reduction of 85% (p = 0.031). Warfarin increased both major bleeding (RR = 4.24; 95% CI 1.85 to 9.68) and minor bleeding (RR = 3.34; 95% CI 1.66 to 6.74). Warfarin increased the risk of major bleeding (RR 5.46; 95% CI 3.04 to 9.81) and minor bleeding (RR 4.01; 95% CI 1.30 to 12.42) also in patients with SCLC. There was no evidence for a significant reduction in mortality in any other cancer subtype., Authors' Conclusions: Existing evidence does not suggest a mortality benefit from oral anticoagulation in patients with cancer. In patients with SCLC, the evidence suggests a survival benefit at six months from warfarin particularly when the disease is extensive. The decision for a patient with extensive SCLC to start warfarin for survival benefit should balance that benefit with the downsides of increased bleeding risk in light of patient values for these outcomes.