Current status and perspectives of conversion therapy for advanced gastric cancer

The concept and strategy of advanced gastric cancer treatment have gradually undergone profound changes with the in-depth understanding of the biology and heterogeneous characteristics of gastric cancer. Moreover, the development and application of new anticancer drugs, including chemotherapy drugs, molecularly targeted drugs and immunotherapy drugs for advanced gastric cancer are reported. The connotation of conversion therapy refers to the unresectable or borderline resectable tumors for surgical technical and/or oncological reasons, after active and effective chemotherapy and other comprehensive treatment, the primary gastric lesions can be reduced to a lower stage, while the metastatic lesions can be effectively controlled, to achieve R0 resection and improve the long-term survival rate. Current promising research results of conversion therapy are mostly from single-arm phase II clinical studies with small samples or retrospective studies. Conversion therapy still faces many challenges, including limited diagnostic and assessment methods, insufficient evidence of highly effective treatment regimens, difficulty in clarifying surgical indications, etc. Therefore, the integrated conversion therapy for advanced gastric cancer needs to be carried out with the close cooperation of a multidisciplinary team. Prospective, multi-center randomized controlled trial studies should be conducted in the future, and precision medicine such as molecular biology should be combined to provide better anticancer drug regimens and higher-level clinical evidence for conversion therapy of advanced gastric cancer.