Abstract：
BACKGROUND: KEYNOTE-177 demonstrated that immunotherapy was superior to chemotherapy for microsatellite-instability-high (MSI-high) metastatic colorectal cancer. Colorectal cancer with peritoneal metastases (CRPM) has a poorer prognosis than other metastatic sites, with an unclear role of immunotherapy. We evaluated trends in immunotherapy use and overall survival (OS).
METHODS: Patients with CRPM and MSI testing were identified in the National Cancer Database (2016-2020). We evaluated immunotherapy use by year and associated patient/hospital factors. OS was compared for immunotherapy versus chemotherapy, cytoreductive surgery (CRS), and immunotherapy plus CRS.
RESULTS: Among 15 322 CRPM patients, 7072 (46.2%) patients had documented MSI testing, with 819 (11.6%) MSI-high. Ninety-eight MSI-high patients received immunotherapy alone (12.3%), increasing from 0% in 2016 to 19.1% in 2020 (p < 0.01). On multivariable analysis, only higher comorbidity was associated with immunotherapy (OR: 2.83 [1.22-6.52]). Two-year OS with immunotherapy versus chemotherapy was 64.2% versus 54.1% (p < 0.05). In patients receiving CRS plus systemic therapy (N = 96), 2-year OS was 68.4%. Among patients who underwent immunotherapy and CRS versus immunotherapy alone, 2-year OS was 80.0% versus 60.0% (p = 0.14).
CONCLUSIONS: Immunotherapy was associated with significantly better survival compared to chemotherapy in MSI-high CRPM. Two-year OS with systemic + CRS was 68.4%. Despite its role in guiding treatment, MSI testing remains low for these patients.
METHODS: Patients with CRPM and MSI testing were identified in the National Cancer Database (2016-2020). We evaluated immunotherapy use by year and associated patient/hospital factors. OS was compared for immunotherapy versus chemotherapy, cytoreductive surgery (CRS), and immunotherapy plus CRS.
RESULTS: Among 15 322 CRPM patients, 7072 (46.2%) patients had documented MSI testing, with 819 (11.6%) MSI-high. Ninety-eight MSI-high patients received immunotherapy alone (12.3%), increasing from 0% in 2016 to 19.1% in 2020 (p < 0.01). On multivariable analysis, only higher comorbidity was associated with immunotherapy (OR: 2.83 [1.22-6.52]). Two-year OS with immunotherapy versus chemotherapy was 64.2% versus 54.1% (p < 0.05). In patients receiving CRS plus systemic therapy (N = 96), 2-year OS was 68.4%. Among patients who underwent immunotherapy and CRS versus immunotherapy alone, 2-year OS was 80.0% versus 60.0% (p = 0.14).
CONCLUSIONS: Immunotherapy was associated with significantly better survival compared to chemotherapy in MSI-high CRPM. Two-year OS with systemic + CRS was 68.4%. Despite its role in guiding treatment, MSI testing remains low for these patients.
摘要：
背景：KEYNOTE-177证明对于微卫星不稳定性高（MSI高）转移性结直肠癌，免疫治疗优于化疗。结直肠癌腹膜转移（CRPM）的预后比其他转移部位差。免疫疗法的作用不清楚。我们评估了免疫治疗使用和总生存期（OS）的趋势。
方法：在国家癌症数据库（2016-2020）中确定了CRPM和MSI测试的患者。我们按年份和相关的患者/医院因素评估了免疫治疗的使用。比较了免疫治疗与化疗的OS，细胞减灭术（CRS），和免疫疗法加CRS。
结果：在15322名CRPM患者中，7072（46.2％）患者有记录的MSI测试，819（11.6%）MSI高。98例MSI高患者仅接受免疫治疗（12.3%），从2016年的0%增加到2020年的19.1%(p<0.01)。在多变量分析中，只有较高的合并症与免疫治疗相关(OR:2.83[1.22-6.52]).免疫治疗与化疗的两年OS分别为64.2%和54.1%(p<0.05)。在接受CRS加全身治疗的患者中（N=96），2年OS为68.4%。在接受免疫治疗和CRS与单纯免疫治疗的患者中，2年OS分别为80.0%和60.0%(p=0.14)。
结论：在MSI高的CRPM中，与化疗相比，免疫治疗与显著更好的生存率相关。系统+CRS的两年OS为68.4%。尽管它在指导治疗方面发挥了作用，这些患者的MSI测试仍然很低。
方法：在国家癌症数据库（2016-2020）中确定了CRPM和MSI测试的患者。我们按年份和相关的患者/医院因素评估了免疫治疗的使用。比较了免疫治疗与化疗的OS，细胞减灭术（CRS），和免疫疗法加CRS。
结果：在15322名CRPM患者中，7072（46.2％）患者有记录的MSI测试，819（11.6%）MSI高。98例MSI高患者仅接受免疫治疗（12.3%），从2016年的0%增加到2020年的19.1%(p<0.01)。在多变量分析中，只有较高的合并症与免疫治疗相关(OR:2.83[1.22-6.52]).免疫治疗与化疗的两年OS分别为64.2%和54.1%(p<0.05)。在接受CRS加全身治疗的患者中（N=96），2年OS为68.4%。在接受免疫治疗和CRS与单纯免疫治疗的患者中，2年OS分别为80.0%和60.0%(p=0.14)。
结论：在MSI高的CRPM中，与化疗相比，免疫治疗与显著更好的生存率相关。系统+CRS的两年OS为68.4%。尽管它在指导治疗方面发挥了作用，这些患者的MSI测试仍然很低。
