A Comprehensive Evaluation of the Effectiveness and Safety of Pembrolizumab for the Treatment of Metastatic Colorectal Cancer: A Systematic Review and Meta-Analysis.

Aim: This comprehensive assessment and quantitative synthesis aimed to assess the effectiveness and safety profile of pembrolizumab, an antagonist of the programmed cell death protein 1 [PD-1] pathway, for individuals with metastatic colorectal carcinoma [mCRC].

Methods: A comprehensive search of scholarly articles was performed using the PubMed and Web of Science [WOS] databases from January 2015 to August 2024. The scope of the search was limited to randomized controlled trials and clinical studies that reported the effectiveness of pembrolizumab in patients with metastatic colorectal cancer [mCRC], which emphasized critical indicators, such as overall survival, progression-free survival, objective response rate, and disease control rate. The research also considered secondary outcomes, including the incidence of severe adverse events and mortality rates. Data ex-traction was performed by two independent reviewers, who employed a standardized data collection form. The subsequent meta-analysis was performed using RevMan 5.0, a soft-ware tool for statistical analysis.

Results: Six studies with 1,634 patients were included, and of these patients, 812 were in the pembrolizumab group, and 822 were in the control group. The results of the meta-analysis indicated via the standard mean difference [SMD] that the overall survival [OS] of patients in the pembrolizumab group was significantly different from that of patients in the control group [SMD = 0.21, 95% CI [0.09, 0.32], P = 0.0005]. The progression-free survival [PFS] of patients in the pembrolizumab group was slightly longer than that of pa-tients in the control group according to the SMD, and this difference was statistically sig-nificant [SMD = 0.11, 95% CI [0.01, 0.22], P = 0.03]. Compared with the objective re-sponse rate [ORR] of patients in the control group, that of patients in the pembrolizumab group was significantly higher [OR = 1.71, 95% CI [1.34, 2.17], P < 0.0001]. The mortali-ty rate in the pembrolizumab group was also significantly different from that in the control group [OR = 0.67, 95% CI [0.52, 0.87], P = 0.002].

Conclusion: Pembrolizumab may help improve overall survival [OS] and progression-free survival [PFS] in patients with metastatic colorectal cancer, which can potentially reduce the mortality rate. More research using larger, well-designed studies is needed to further confirm these findings.