The programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway plays a crucial role in the immune escape mechanism and growth of cancer cells in endometrial cancer (EC). Clinical trials investigating PD-1/PD-L1 inhibitor have shown promising results in other cancers, but their efficacy in EC still remains uncertain. Therefore, this meta-analysis aims to provide an updated and robust analysis of the effectiveness and safety of PD-1/PDL1 inhibitor as single-agent immunotherapy in EC, focusing on the objective response rate (ORR), disease control rate (DCR), and adverse events (AEs). This meta-analysis utilized STATA version 17 and RevMan version 5.4 software to pool the results of relevant studies. Five studies conducted between 2017 and 2022, comprising a total of 480 EC patients enrolled for PD-1/PD-L1 inhibitor immunotherapy met the inclusion criteria. The pooled proportion of EC patients who achieved ORR through PD-1/PD-L1 inhibitor treatment was 26.0% (95% CI: 16.0–36.0%;p< 0.05). Subgroup analysis based on mismatch repair (MMR) status showed an ORR of 44.0% (95% CI: 38.0–50.0%;p= 0.32) for the deficient mismatch repair (dMMR) group and 8.0% (95% CI: 0.0–16.0%;p= 0.07) for the proficient mismatch repair (pMMR) group. Pooled proportion analysis by DCR demonstrated an odds ratio (OR) of 41.0% (95% CI: 36.0–46.0%,p= 0.83) for patients undergoing PD-1/PD-L1 inhibitor treatment. Subgroup analysis based on MMR status revealed DCR of 54.0% (95% CI: 47.0–62.0%;p= 0.83) for the dMMR group, and 31.0% (95% CI: 25.0–39.0%;p= 0.14) for the pMMR group. The efficacy of PD-1/PD-L1 inhibitors was significantly higher in the dMMR group compared to the pMMR group, in terms of both ORR (OR = 6.30; 95% CI = 3.60–11.03;p< 0.05) and DCR (OR = 2.57; 95% CI = 1.66–3.99;p< 0.05). In terms of safety issues, the pooled proportion of patients experiencing at least one adverse event was 69.0% (95% CI: 65.0–73.0%;p> 0.05), with grade three or higher AEs occurring in 16.0% of cases (95% CI: 12.0–19.0%;p> 0.05). Based on the subgroup analysis of MMR status, PD-1/PD-L1 inhibitor immunotherapy showed significantly better efficacy among dMMR patients. These findings suggest that patients with dMMR status may be more suitable for this treatment approach. However, further research on PD-1/PD-L1 inhibitor immunotherapy strategies is needed to fully explore their potential and improve treatment outcomes in EC.
程序性细胞死亡蛋白1（PD-1）/程序性细胞死亡配体1（PD-L1）通路在子宫内膜癌（EC）的免疫逃逸机制及癌细胞生长中起着关键作用。针对PD-1/PD-L1抑制剂的临床试验在其他癌症中已显示出良好疗效，但其在子宫内膜癌中的有效性仍不明确。因此，本荟萃分析旨在对PD-1/PD-L1抑制剂作为单药免疫疗法治疗子宫内膜癌的有效性及安全性提供最新、可靠的分析，重点关注客观缓解率（ORR）、疾病控制率（DCR）及不良事件（AEs）。本研究使用STATA 17版和RevMan 5.4软件对相关研究结果进行合并分析。纳入2017年至2022年间进行的五项研究，共包含480例接受PD-1/PD-L1抑制剂免疫治疗的子宫内膜癌患者。经PD-1/PD-L1抑制剂治疗后获得客观缓解的患者合并比例为26.0%（95% CI：16.0–36.0%；p < 0.05）。基于错配修复（MMR）状态的亚组分析显示，错配修复缺陷（dMMR）组的客观缓解率为44.0%（95% CI：38.0–50.0%；p = 0.32），而错配修复完整（pMMR）组为8.0%（95% CI：0.0–16.0%；p = 0.07）。通过疾病控制率进行的合并比例分析显示，接受PD-1/PD-L1抑制剂治疗患者的比值比（OR）为41.0%（95% CI：36.0–46.0%，p = 0.83）。基于MMR状态的亚组分析显示，dMMR组的疾病控制率为54.0%（95% CI：47.0–62.0%；p = 0.83），pMMR组为31.0%（95% CI：25.0–39.0%；p = 0.14）。无论在客观缓解率（OR = 6.30；95% CI = 3.60–11.03；p < 0.05）还是疾病控制率（OR = 2.57；95% CI = 1.66–3.99；p < 0.05）方面，PD-1/PD-L1抑制剂在dMMR组中的疗效均显著高于pMMR组。在安全性方面，发生至少一种不良事件的患者合并比例为69.0%（95% CI：65.0–73.0%；p > 0.05），其中3级或以上不良事件发生率为16.0%（95% CI：12.0–19.0%；p > 0.05）。基于MMR状态的亚组分析表明，PD-1/PD-L1抑制剂免疫疗法在dMMR患者中疗效显著更佳。这些发现提示dMMR状态的患者可能更适合该治疗方案。然而，仍需进一步研究PD-1/PD-L1抑制剂免疫治疗策略，以充分挖掘其潜力并改善子宫内膜癌的治疗效果。
肿瘤(癌症)患者之家