Primary thromboprophylaxis (PTP) in ambulatory patients with lung cancer receiving chemotherapy: A systematic review and meta-analysis of randomized controlled trials (RCTs).

Abstract

Thromboembolism (TE) is a leading cause of death in cancer patients. Primary thromboprophylaxis (PTP) in ambulatory cancer patients receiving chemotherapy has been debated and considered to potentially improve survival by reducing TE occurrence. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) in ambulatory lung cancer (LC) patients on chemotherapy to determine the benefit and risk of PTP with low-molecular-weight heparins (LMWHs). A literature search using MEDLINE and EMBASE databases was performed through June 2016. RCTs with venous thromboembolism (VTE) reduction as primary or secondary endpoints were included. Mantel-Haenszel method was used to estimate the pooled event risk ratio as well as pooled absolute risk difference with 95% confidence interval (CI). A total of 4315 LC patients from six studies were available for analysis. PTP lasted for 4 to 6 months. The venous thromboembolism (VTE) incidence was 4.0% and 7.9% in LMWH and control groups, respectively (risk ratio, 0.510 (95% CI, 0.397-0.654, P<0.001). The absolute risk difference in VTE was -0.039 (95% CI, -0.053 to -0.025, P<0.001), with an estimated number needed to treat (NNT) of 25 to prevent one VTE event. The pooled risk ratio for major bleeding was 1.468 (95% CI, 0.785-2.746, P=0.229). The pooled risk ratio for overall survival was statistically nonsignificant at 1.020 (95% CI, 0.938-1.109, P=0.648). Routine PTP for ambulatory LC patients receiving chemotherapy is not recommended and further studies are necessary to define a subset of ambulatory LC patients receiving chemotherapy who may benefit from PTP.