The effectiveness and safety of thromboprophylaxis in cancer patients based on Khorana score: a meta-analysis and systematic review of randomized controlled trials.

Introduction: Cancer patients receiving chemotherapy are a high risk of VTE, yet the importance of thromboprophylaxis for cancer patients that are at high risk of developing VTE is still controversial.
Aim: To calculate the benefits and harms of thromboprophylaxis, compared to placebo, in ambulatory high-risk cancer patients that are receiving chemotherapy.
Methods: We searched PubMed, Embase, Web of Science, the Cochrane Library, Cochrane Central Register of Controlled Trials, Chinese Biomedical Literature Database, WANFANG Data, Chinese National Knowledge Infrastructure and Chinese Scientific Journal Database for randomized controlled trials (RCTs) describing benefits and harms of thromboprophylaxis. Statistical analysis was performed using Stata software (version 15.1).
Results: We included six studies, which contained a total of 3240 cancer patients with thromboprophylaxis and 2874 cancer patients without thromboprophylaxis. Thromboprophylaxis was effective in high-risk patients with two points or higher (RR 0.51, 95% CI 0.36-0.71, I ²  = 0.0%, P = 0.526). It was associated with an increase in bleeding events (RR 1.65, 95% CI 1.14-2.40, I ²  = 0.0%, P = 0.498) and was mainly efficient in reducing the risk of pulmonary embolism (RR 0.56, 95% CI 0.33-0.96, I ²  = 0.0%, P = 0.263). The risk of major (RR 1.85, 95% CI 0.87-3.94, I ²  = 0.0%, P = 0.888) and non-major (RR 1.59, 95% CI 0.96-2.62, I ²  = 16.3%, P = 0.303) bleeding showed no significant difference with or without thromboprophylaxis. There was no reduction in all-cause mortality with thromboprophylaxis (RR 0.95, 95% CI 0.78-1.18, I ²  = 22.0%, P = 0.277).
Conclusion: Thromoboprophylaxis is effective and safe in cancer patients that are at high risk for developing VTE with chemotherapy.