晚期胃癌的治疗一直是胃癌治疗中的难点。Ⅳ期胃癌由于存在转移灶，往往难以达到根治性切除。转化治疗是指通过化疗、靶向治疗、免疫治疗等非外科手段，使肿瘤退缩甚至部分局部病灶消失，从而使得初始难以行根治性手术的病人获得R0切除机会。目前晚期胃癌的治疗仍以姑息手术和对症治疗为主，晚期胃癌的转化治疗尚未形成共识。评价胃癌转化治疗效果的主要指标是转化治疗后R0切除率、疾病控制率以及客观缓解率等实体瘤的疗效评价标准(response evaluation criteria in solid tumor, RECIST)。不同治疗手段和方案的疗效各异。转化治疗的最终目的是争取R0手术机会，故转化治疗后手术的合理实施也是关键问题。Yoshida提出的四分类法是目前最为普遍接受的手术决策依据。目前晚期胃癌的转化治疗仍困难重重，缺乏高质量研究。深入研究肿瘤微环境和开发新的治疗方法或许是今后研究的大方向。

The treatment of far-advanced gastric cancers has always been challenging. Due to the presence of metastases, stage Ⅳ gastric cancers are often difficult to achieve radical resection. Conversion therapy refers to non-surgical me-thods such as chemotherapy, targeted therapy, and immunotherapy to make the tumor shrink or even disappear in some areas, so that the patients who are unresectable originally can obtain the opportunity of R0 resection. At present, palliative surgery and symptomatic treatment are still the paramount methods for far-advanced gastric cancers, and no consensus has been reached on conversion therapy for gastric cancer. The main indicators for evaluating the effectiveness of conversion therapy for gastric cancer include R0 resection rate after conversion therapy, disease control rate and objective response rate of the response evaluation criteria in solid tumor (RECIST). The different treatment and schemes have different effects. The ultimate goal of conversion therapy is to strive for opportunity of R0 resection, so the rational implementation of surgery after conversion therapy is also a key issue. The four classifications proposed by Yoshida are the most commonly accepted basis for surgical decision. At present, the conversion therapy for far-advanced gastric cancer is still challenging with the lack of high-quality research. In-depth study of the tumor microenvironment and the development of new therapeutic approaches may be the major research direction in future.