Background: The survival of advanced gastric cancer (GC) is dismal, and effects of antiangiogenic agents remain inconclusive. The purpose of this study is to assess combination of chemotherapy with antiangiogenic therapy versus traditional chemotherapy.Methods: To achieve the goal of scientific rigor, statistics from both referenced works and experiments were analyzed. We carefully searched for the referenced works by retrieving, as well as analyzing, literature databases for information on antiangiogenic therapy compared to other therapeutic approaches used to treat GC patients. Two groups were defined in the experiment: experimental and control groups. The experimental group was treated with antiangiogenic drug, and the control group was treated with standard chemotherapy or placebo.Results: The study included a total of 3240 participants. Overall, there was significant improvement in overall survival (hazard ratio [HR] = 0.78, 95% confidence interval [CI]: 0.67-0.91, P = 0.002), progression-free survival (HR 0.65, 95% CI: 0.52-0.81, P = 0.0002), objective response rate (risk ratio [RR] = 1.58, 95% CI: 1.33-1.88, P < 0.00001), and disease control rate (RR 2.44, 95% CI: 1.57-3.78, P < 0.0001) in the group with antiangiogenic drug versus the group with standard chemotherapy or placebo. Moreover, this new treatment approach showed tolerable toxicity.Conclusion: This study confirms the superior efficacy of combination therapy with antiangiogenic agents in comparison to traditional chemotherapy regimens for patients with GC. Moreover, this new treatment approach showed tolerable toxicity. This meta-analysis provides important information for clinicians who are interested in using antiangiogenic therapies to treat GC patients.Abbreviations: ASCO = American Society of Clinical Oncology, CI = confidence interval, DCR = disease control rate, ECOG = Eastern Cooperation Oncology Group, GC = gastric cancer, HR = hazard ratio, ORR = objective response rate, OS = overall survival, PFS = progression-free survival, RCT = randomized controlled trial, RR = risk ratio.

Background: Deficient mismatch repair (dMMR) or the microsatellite instability (MSI) phenotype occupied approximately 15-18% of CRC patients. Previous studies showed that dMMR/MSI status is a favorable prognostic factor for stage II/III CRC patients. For metastatic colorectal cancer (mCRC) patients, only 5% of patients have the dMMR/MSI-H phenotype. The relationship between dMMR/MSI, chemosensitivity and survival in mCRC patients of real-world is still not clear. Materials and methods: In this study, we enrolled 77 dMMR/MSI-H mCRC patients and compared their clinicopathological characteristics with those of 510 proficient MMR (pMMR) or microsatellite stable (MSS) mCRC patients. With propensity score matching (PSM) analysis, we further compared the chemosensitivity and survival of dMMR/MSI-H mCRC patients with pMMR/MSS patients. We also analyzed the efficacy of different chemotherapy and target therapy in the dMMR/MSI-H population. Results: In PSM cohort, the objective response rate (ORR) of mCRC patients with dMMR/MSI-H undergoing first-line palliative chemotherapy was 35.2%, which was similar with patients with pMMR/MSS (35.4%, p = 1.00). The median progression-free survival (PFS) of first-line chemotherapy was significantly different (dMMR/MSI-H vs pMMR/MSS = 7.4 months vs 10.2 months; HR = 0.74; 95%CI, 0.57-0.98; p = 0.03). Overall survival (OS) of patients did not significantly differ by status (dMMR/MSI-H vs pMMR/MSS = 40.0 months vs 41.3 months; HR = 1.09; 95%CI, 0.74-1.59; p = 0.68). For second-line palliative chemotherapy, there was no difference in ORR (p = 0.53) or in PFS (HR = 0.88; 95%CI, 0.59-1.33; p = 0.56) between dMMR/MSI-H and pMMR/MSS tumors. We also found that in the overall cohort, the ORR of patients who received oxaliplatin-based and irinotecan-based chemotherapy were 28.8% and 54.5%, respectively, which were not significantly different (p = 0.16). Our results also showed that the use of bevacizumab could lead to a significantly higher ORR in dMMR/MSI-H mCRC patients compared to chemotherapy alone (55.0% vs 22.2%; p = 0.02), whereas cetuximab could not. Conclusion:The dMMR/MSI-H is not a prognostic factor for mCRC patients but is correlated with shorter PFS to first-line palliative chemotherapy.