Risk Factors of Venous Thromboembolic Events after Breast Cancer Surgeries; A Meta-Analysis of 166929 Patients

Introduction: Venous thromboembolism (VTE) is the second most common cause of death among patients with breast cancer. In particular, VTE accounted for 20% of deaths after radical mastectomy. Owing to the devastating sequels associated with VTE and its financial impact, the current study was conducted to reveal the possible risk factors of VTE after breast cancer surgeries. Materials and Methods: Extensive systematic literature review, from inception up to 1 October 2019, was performed throughout 12 databases to reveal all clinical studies reported the risk factors of VTE after breast cancer surgeries. Pooled analysis was implemented using Review Manager. Results: This meta-analysis included 8 articles that encompassed an overall 166929 patients. There was no statistically significant difference between patients developed VTE and those not developed such condition regarding Caprini total score (SMD0.5;95%CI-0.58,1.57;P=0.36). Subsequently, patients developed VTE were elder than patients did not develop such complications (MD1.21;95%CI 1.06,1.35;P<0.001). Patients had pre-operative diabetes mellitus (OR 0.69;95%CI0.49,0.98;P=0.04) or pulmonary disease (OR1.43;95%CI1.09,1.88;P=0.01) were more susceptible to experience post-operative VTE, relative to other patients. Besides that, post-operative hospitalization stays were significantly longer among patients experienced VTE, relative to patients did not experience such complications (MD 2.6;95%CI 2.54,2.66;P<0.001). Patients subjected to radical mastectomy and primary reconstruction were more vulnerable to have VTE post-operatively (OR 2.66;95%CI 1.90,3.71;P<0.001). Similarly, patients received concurrent venous catheterization were more susceptible to develop VTE post-operatively (OR 2.13;95%CI 1.22,3.73;P<0.00=0.008). On the contrary, post-operative hormonal therapy, radiotherapy, or chemotherapy were not statistically significant risk factors of VTE after breast cancer surgeries. Conclusions: Elderly patients and those with pre-operative diabetes mellitus or pulmonary diseases and patients subordinated to primary reconstruction after radical mastectomy were more susceptible to develop VTE. Understanding these factors will aid health care providers to optimize the optimal preventive strategies of VTE after breast cancer surgeries.