Meta-analysis of randomized controlled trials on primary ambulatory thromboprophylaxis in patients with nonpancreatic gastrointestinal cancers receiving chemotherapy.

Primary ambulatory thromboprophylaxis (PATP) in patients with solid malignancies is not routinely indicated. We performed a meta-analysis of randomized controlled trials (RCTs) to determine the benefit and risk of PATP in patients with nonpancreatic gastrointestinal cancers receiving chemotherapy. RCTs with venous thromboembolism (VTE) reduction as primary or secondary endpoints were included. A total of 1932 patients from subgroups of 3 RCTs were eligible. The VTE incidence was 1.26% and 2.55% in PATP and control arms, respectively (risk ratio 0.49; confidence interval 0.25 to 0.96; P = 0.04), with a number needed to treat of 78 to prevent one VTE event. In gastric and gastroesophageal junction cancer patients, the VTE incidence was 1.37% and 3.40% in PATP and control arms, respectively (risk ratio 0.40; confidence interval 0.13 to 1.24; P = 0.11). PATP should not be recommended in patients with nonpancreatic gastrointestinal cancers on chemotherapy.