Abstract:

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.

Key words: Far-advanced gastric cancer, Conversion therapy, Tumor microenvironment