A meta-analysis of bevacizumab’s cardiovascular risks in patients treated for colorectal cancer.

Abstract

113 Background: Bevacizumab (BVZ), a recombinant humanized monoclonal IgG antibody, is commonly used as first- and second-line adjuvant therapy in metastatic colorectal cancer. Recent guidelines have shown that a combination of three cytotoxic drug regimens FOLFOX (fluorouracil, leucovorin and oxaliplatin) along with BVZ is regarded as one of the first-line options. As we see an upward trend in using BVZ; it is crucial to analyze the side effects and potential toxicities. A frequent adverse effect with BVZ is hypertension. The prevailing hypothesis for the mechanism of BVZ induced hypertension is an increase in vascular tone due to the inhibition of VEGF-mediated vasodilation. A persistent elevation of arterial blood pressure is generally asymptomatic, but unmanaged hypertension can lead to cardiovascular complications, encephalopathy, and subarachnoid hemorrhage. Therefore, this meta-analysis aims to evaluate and assess the risk of BVZ induced hypertension. Methods: Our search included articles from PubMed, EMBASE, Web of Science, and Cochrane Library from 1980 to March 2022. Randomized controlled trials and clinical trials with BVZ as an add-on therapy mentioning cardiovascular side effects were included. Full analysis control group included various guideline directed chemotherapies and the subgroup analysis control group focused on FOLFOX therapy. A random-effects model was used with Review Manager, and a P value < 0.05 was considered significant. Results: We included a total of 17,807 patients in our study with an average age of 65 years. Analysis pooled from 19 RCTs showed that the odds of hypertension (Grade 3 or more) in patients treated with BVZ were about four times higher than the control group (OR 3.82, 95% CI 3.35-4.36, p-value < 0.00001, I2 = 78%). In a subgroup analysis, BVZ was compared with FOLFOX group, with odds of hypertension (Grade 3 or more) in BVZ group being about five times higher than in FOLFOX group (OR 5.24, 95% CI 4.06-6.77, p-value < 0.00001, I2 = 58%). Conclusions: Our meta-analysis demonstrates a significant cardiovascular risk of Bevacizumab when added to the standard regime for advanced colorectal cancer treatment. When BVZ was used as an add-on therapy to FOLFOX regimens for colorectal cancer, it was associated with about five times higher odds of developing hypertension (Grade 3 or more) in the treatment group with BVZ. Previous RCTs have demonstrated that BVZ add-on therapy to the standard regime is safe and without significant risk of toxicity. Our findings are important as they give vital information in assessing the risk-benefit ratio of adding BVZ, especially in a population with vascular comorbidities. Now that we have established the statistical significance of hypertensive risk with BVZ, it will be interesting to see how these events can be prevented in patients treated for metastatic colorectal cancer. Dedicated RCTs are needed to confirm these findings.