Efficacy of immunotherapy with PD-1 inhibitor in colorectal cancer: a meta-analysis

Abstract

Aim: PD-1 inhibitors have a leading role among immunotherapy while its efficacy on colorectal cancer (CRC) patients did not reach consensus and the small sample size remains as a limitation. Therefore, we undertook a meta-analysis on the effects of the monotherapy anti-PD-1 inhibitors in treating metastatic colorectal cancer (mCRC). Materials & methods: We searched databases to identify studies on efficacy of anti-PD-1 inhibitor on CRC. Objectives were objective response rate, progression-free survival rate, disease control rate and overall survival rate with their 95% CI. Results: The overall survival rate at 1-year was 64.2% (95% CI: 0.46-0.83). Disease control rate was 56.5% (CI: 0.27-0.86) and the objective response rate as 19.7% (CI: 0.08-0.32). The 1-year-progression-free survival rate was 38.4% (CI: 0.12-0.66). Sensitivity analysis and subgroup analysis were also conducted. Conclusion: The monotherapy anti-PD-1 inhibitors are effective in treating mCRC and could be a new option for dMMR mCRC patient in first-line treatment.

Keywords: PD-1; anti-PD-1 inhibitors; colorectal cancer; immunotherapy; meta-analysis; programmed cell death protein-1.