Bevacizumab improves survival in metastatic colorectal cancer patients with primary tumor resection: A meta-analysis

Dedong Cao,Yongfa Zheng,Ximing Xu,Huilin Xu,Wei Ge

doi:10.1038/s41598-019-56528-2

Abstract

It is not well determined whether primary tumor resection is associated with better outcomes in metastatic colorectal cancer (mCRC) patients treated with bevacizumab. In this meta-analysis, we aimed to assess the prognostic role of primary tumor resection in mCRC treated with bevacizumab. Electronic databases including the Cochrane library, Embase, and Pubmed were searched until April 2018. Clinical studies assessing the influence of primary tumor resection on the efficacy of bevacizumab in patients with mCRC were identified. The primary endpoint was overall survival (OS), and the secondary endpoint was progression-free survival (PFS). Seven studies including 2760 mCRC patients were finally included. The results of the meta-analysis were in favor of bevacizumab to patients with resected primary tumor in terms of OS (HR = 0.50, 95%CI: 0.39–0.64; p < 0.01), and PFS (HR = 0.65, 95%CI: 0.51–0.81; p < 0.01). Administration of bevacizumab in mCRC patients with resected primary tumor had a better OS (HR = 0.65, 95%CI: 0.56–0.74; p < 0.01), when compared to chemotherapy(CT). Adding bevacizumab to mCRC patients without resection of primary tumor also had a better OS (HR = 0.78, 95%CI: 0.65–0.94; p < 0.01) and PFS (HR = 0.71, 95%CI: 0.57–0.88; p < 0.01) compared to chemotherapy alone. In conclusion, mCRC patients with resected primary tumor have better survival than those without surgery of primary tumor when treated with bevacizumab. Primary tumor resection status should be taken into consideration when using bevacizumab in mCRC.

Highlights

It is not well determined whether primary tumor resection is associated with better outcomes in metastatic colorectal cancer patients treated with bevacizumab
The inclusion criteria were: (1) clinical studies that included metastatic Colorectal cancer (CRC) (mCRC) patients, either randomized controlled trials or retrospective studies with sufficient baseline and endpoint information; (2) mCRC patients treated with bevacizumab in combination with or without traditional chemotherapy; (3) clear definition of overall survival (OS) and progression-free survival (PFS); (4)Comparing impact of primary tumor resection versus no resection on OS and/or PFS in mCRC treated with bevacizumab; (5) sufficient data for extracting hazard ratio(HR) and its 95% confidence interval(CI) in term of OS and PFS directly or indirectly(survival curve provided)
Whether primary tumor resection could affect the survival outcome of mCRC patients treated with bevacizumab, it was still in debate

Summary

Introduction

It is not well determined whether primary tumor resection is associated with better outcomes in metastatic colorectal cancer (mCRC) patients treated with bevacizumab. There are accumulating clinical studies[9,10,11,12,13,14,15] that assessing the efficacy of bevacizumab is influenced by primary tumor resection or not in mCRC These studies suggested that surgery of primary tumor was associated with better survival when managed with bevacizumab. We identified clinical trials assessing the impact of primary tumor resection on the efficacy of bevacizumab in mCRC patients and performed a meta-analysis by using HRs of resection versus no resection for survival in mCRC patients after bevacizumab treatment. With this purpose, we expected to establish an evidence-based relationship between primary tumor resection and efficacy of bevacizumab

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