[Multicenter real-world study on safety and efficacy of neoadjuvant therapy in combination with immunotherapy for colorectal cancer].

Objective: To provide reference and evidence for clinical application of neoadjuvant immunotherapy in patients with colorectal cancer through multicenter large-scale analysis based on real-world data in China. Methods: This was a retrospective multicenter case series study. From January 2017 to October 2021, data of 94 patients with colorectal cancer who received neoadjuvant immunotherapy in Peking University Cancer Hospital (55 cases), Union Hospital of Tongji Medical College of Huazhong University of Science and Technology (19 cases), Sun Yat-sen University Cancer Center (13 cases) and Changhai Hospital of Navy Medical University (7 cases) were retrospectively collected, including 48 males and 46 females. The median age was 58 years. Eighty-one cases were rectal cancer and 13 cases were colon cancer (2 cases of double primary colon cancer). Twelve cases were TNM staging II and 82 cases were stage III. Forty-six cases were well differentiated, 37 cases were moderately differentiated and 11 cases were poorly differentiated. Twenty-six patients (27.7%) with mismatch repair defects (dMMR) and microsatellite instability (MSI-H) were treated with immunotherapy alone, mainly programmed cell death protein-1 (PD-1); sixty-eight cases (72.3%) with mismatch repair proficient (pMMR) and microsatellite stability (MSS) were treated with immune combined with neoadjuvant therapy, mainly CapeOx (capecitabine+oxaliplatin) combined with PD-1 antibody plus long- or short-course radiotherapy, or PD-1 antibody combined with cytotoxic T lymphocyte associated antigen 4 (CTLA-4) antibody. Analysis and evaluation of adverse events during neoadjuvant immunotherapy were performed according to the National Cancer Institute Common Toxicity Standard version 3.0; the surgical complications were evaluated according to the Clavien-Dindo grading standard; the efficacy evaluation of neoadjuvant immunotherapy included the following indicators: major pathological remission (MPR) was defined as tumor regression induced by neoadjuvant therapy in pathology residual tumor ≤10%; pathological complete response (pCR) was defined as tumor regression induced by neoadjuvant therapy without residual tumor in pathology; the tumor response rate was disease control rate (DCR), namely the proportion of complete response (CR), partial response (PR) and stable disease (SD) in the whole group; the objective response rate (ORR) was CR+PR. Results: The median cycle of neoadjuvant immunotherapy was 4 (1-10) in whole group, and the incidence of immune-related adverse reactions was 37.2% (35/94), including 35 cases (37.2%) of skin-related adverse reactions, 21 cases (22.3%) of thyroid dysfunction and 8 cases (8.5%) of immune enteritis, of which grade III or above accounted for 1.1%. The median interval between completion of neoadjuvant therapy and surgery was 30 (21-55) days. There were 81 cases of radical resection of rectal cancer, 11 cases of radical resection of colon cancer, and 2 cases of colon cancer combined with other organ resection. The primary tumor resection of all the patients reached R0. The incidence of surgical-related complications was 22.3% (21/94), mainly anastomotic leakage (4 cases), pelvic infection (4 cases), abdominal effusion (3 cases), anastomotic stenosis (3 cases ) and abdominal and pelvic hemorrhage (2 cases). Grade I-II complications developed in 13 cases (13.8%), grade III and above complications developed in 8 cases (8.5%), no grade IV or above complications were found. During a median follow-up of 32 (1-46 ) months, DCR was 98.9% (93/94), ORR was 88.3 % (83/94), pCR was 41.5% (39/94), MPR was 60.6% (57/94). The pCR rate of 26 patients with dMMR and MSI-H undergoing simple immunotherapy was 57.7% (15/26), and MPR rate was 65.4% (17/26). The pCR rate of 68 pMMR and MSS patients undergoing combined immunotherapy was 35.3%(24/68), and MPR rate was 58.8% (40/68). Conclusions: Neoadjuvant immunotherapy has favorable tumor control rate and pathological remission rate for patients with initial resectable colorectal cancer. The incidences of perioperative adverse reactions and surgical complications are acceptable.目的： 通过总结分析国内多中心、真实世界的大样本数据，为联合免疫治疗的新辅助治疗对结直肠癌患者的临床应用提供借鉴和依据。 方法： 本研究为回顾性、多中心、病例系列研究。回顾性收集2017年1月至2021年10月期间，北京大学肿瘤医院（55例）、华中科技大学同济医学院附属协和医院（19例）、中山大学肿瘤防治中心（13例）和海军军医大学附属长海医院（7例）共计94例患者联合新辅助免疫治疗的结直肠癌患者资料，其中男性48例，女性46例；中位年龄58岁。直肠癌81例，结肠癌13例（2例为结肠双原发癌）；肿瘤TNM分期：Ⅱ期12例，Ⅲ期82例；肿瘤高分化46例，中分化37例，低分化11例。26例（27.7%）为错配修复缺陷（dMMR）和微卫星高度不稳定（MSI-H），行单纯免疫治疗，主要为程序性死亡蛋白-1（PD-1）；68例（72.3%）为错配修复正常（pMMR）和微卫星稳定（MSS），行免疫联合新辅助治疗，主要为CapeOx（卡培他滨+奥沙利铂）联合PD-1+长程或短程放疗，或PD-1联合细胞毒T淋巴细胞相关抗原4（CTLA-4）。按美国国立癌症研究所通用毒性标准3.0版分析评价新辅助联合免疫治疗期间的不良反应；了解手术情况并按照Clavien-Dindo分级标准评价手术并发症；联合新辅助免疫治疗的疗效评估包括以下指标：主要病理学缓解（MPR），定义为新辅助治疗诱导的肿瘤消退在病理上残留肿瘤≤10%；病理完全缓解（pCR）定义为新辅助治疗诱导的肿瘤消退患者在病理上未见残留肿瘤；肿瘤评效为疾病控制率（DCR），即完全缓解（CR）、部分缓解（PR）和疾病稳定（SD）患者在全组中所占的比例；客观缓解率（ORR），为CR+PR。 结果： 全组94例患者接受新辅助联合免疫治疗的中位周期数为4（1~10）个，免疫相关不良反应发生率为37.2%（35/94），包括皮肤相关不良反应35例（37.2%）、甲状腺功能异常21例（22.3%）和免疫性肠炎8例（8.5%），其中Ⅲ级不良反应占1.1%。末次新辅助联合免疫治疗至手术的中位时间为30（21~55） d，直肠癌根治术81例，结肠癌根治术11例，结肠癌联合其他脏器切除2例；全部患者原发灶切除均达到R(0)。手术相关并发症发生率为22.3%（21/94），主要为吻合口漏（4例）、盆腔感染（4例）、腹腔积液（3例）、吻合口狭窄（3例）和腹盆腔出血（2例）；Ⅰ~Ⅱ级并发症13例（13.8%），Ⅲ级并发症8例（8.5%），无Ⅳ级及以上并发症。全组患者中位随访32（1~46）个月，DCR为98.9%（93/94），ORR为88.3%（83/94），pCR率41.5%（39/94），MPR率60.6%（57/94）。行单纯免疫治疗的26例dMMR和MSI-H患者pCR率为57.7%(15/26)，MPR率为65.4%(17/26)。行联合免疫治疗的68例pMMR和MSS患者pCR率为35.3%(24/68)，MPR率为58.8%（40/68）。 结论： 对于初始可切除的结直肠癌患者，新辅助联合免疫治疗具有很好的肿瘤控制率和病理缓解率；围手术期不良反应及手术并发症发生率可以接受。.