胃癌（GC）IV期患者接受免疫化疗后进行手术转化的临床益处尚不确定。本研究旨在阐明对这类患者进行手术转化的临床结果。本回顾性队列研究纳入了连续接受免疫检查点抑制剂（ICIs）、化疗和/或抗HER2靶向治疗作为一线治疗的胃癌IV期患者。使用Kaplan-Meier方法估计累积生存曲线。进行逻辑回归和Cox回归分析以确认与手术转化和生存相关的因素。研究纳入136名患者。疾病控制率为72.1%（98/136），客观缓解率为58.8%（80/136），完全缓解率为5.9%（8/136）。在98名疾病控制患者中，56名患者接受姑息性免疫化疗，中位无进展生存期（PFS）和总生存期（OS）分别为9.2个月和16.2个月；剩余42名患者接受手术转化，经过19.0个月的中位随访，中位PFS无法确定，一年OS和PFS率分别为96.6%和89.1%。R0切除率达到90.5%（38/42）。42名患者中有7名达到病理完全缓解，其中3名患者表现出HER2阳性。在围手术期观察期间未观察到导致死亡的严重并发症。多因素分析表明，PD-L1 CPS ≥5（比值比为0.22，95%置信区间为0.08-0.57，P=0.002）有利于成功进行手术转化，而粘液性腺癌（风险比为6.29，95%置信区间为1.56-25.36，P=0.010）是进行手术转化的患者生存的不良预后因素。对于在免疫化疗后获得良好临床反应的胃癌IV期患者而言，手术转化具有显著的生存益处。粘液性腺癌患者可能会出现术后复发增加的情况。 © 2023 The Author(s). 由Wolters Kluwer Health, Inc.出版。

The clinical benefit of conversion surgery following immunochemotherapy in patients with stage IV gastric cancer (GC) remains uncertain. This study aims to clarify the clinical outcomes of conversion surgery for such patients.This retrospective cohort study enrolled consecutive patients with stage IV GC treated with a combination of immune checkpoint inhibitors (ICIs) and chemotherapy and/or anti-HER2 targeted therapy as first-line therapy. Cumulative survival curves were estimated using Kaplan-Meier method. Logistic regression and Cox regression analyses were conducted to identify factors associated with conversion surgery and survival, respectively.Among the 136 patients included in the study. The disease control rate was 72.1% (98/136), with objective response rate in 58.8% (80/136) and complete response rate in 5.9% (8/136). Among 98 patients with disease control, 56 patients underwent palliative immunochemotherapy with median PFS and OS at 9.2 and 16.2 months, respectively; the remaining 42 patients underwent conversion surgery, yielding an unreached median PFS over a 19.0-month median follow-up, accompanied by one-year OS and PFS rates of 96.6% and 89.1%, respectively. The R0 resection rate reached 90.5% (38/42). 7 out of 42 patients achieved pathological complete response, of whom 3 patients demonstrated HER2 positivity. No serious complications leading to death were observed during the perioperative period. Multivariate analysis indicated that PD-L1 CPS ≥5 (odds ratio, 0.22; 95% CI, 0.08-0.57; P=0.002) favored successful conversion surgery, while signet ring cell carcinoma (hazard ratio, 6.29; 95% CI, 1.56-25.36; P=0.010) was the poor prognostic factor associated with survival in patients who underwent conversion surgery.Conversion surgery holds the potential for significant survival benefits in stage IV GC patients who have achieved a favorable clinical response to immunochemotherapy. Individuals with signet ring cell carcinoma may experience increased post-conversion surgery recurrence.Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.