Updated meta-analysis of randomized controlled trials on primary outpatient thromboprophylaxis in patients with gastric and gastroesophageal junction cancers receiving chemotherapy.

Advanced gastric cancer is a highly thrombogenic cancer per Khorana score. Recent clinical practice guidelines suggest primary outpatient thromboprophylaxis (POTP) for patients with a Khorana score ≥2. We performed an updated meta-analysis to evaluate the benefit of POTP in patients with gastric cancer and gastroesophageal junction cancers receiving chemotherapy. Randomized controlled trials with reduction in venous thromboembolism (VTE) as a primary or secondary endpoint were incorporated. A total of 631 patients from subgroups of three randomized controlled trials were included. The VTE incidence was 1.6% and 5.1% in POTP and control groups, respectively (risk ratio 0.31; confidence interval 0.11 to 0.83; P  = 0.02), with a number needed to treat of 29 to prevent one VTE event. Even though the recent clinical practice guidelines suggest POTP in patients with gastric cancer and gastroesophageal junction cancers, our meta-analysis findings do not support the routine use of POTP in those patients.