[Present status of preoperative staging and contemplation on preoperative precision staging for gastric cancer].

The aim of the preoperative staging of gastric cancer was to evaluate the depth of tumor infiltration (T-stage), the extent or number of metastasized lymph nodes (N-stage), and distant metastasis (M-stage) before surgery, to develop an optimal therapeutic scheme for the patients with gastric cancer. Traditional methods of preoperative staging for gastric cancer are usually imaging diagnostic techniques, such as endoscopic ultrasonography (EUS), CT scan, magnetic resonance imaging (MRI) and laparoscopic exploration. At present, the accuracy of preoperative TNM staging of gastric cancer can generally reach 70% to 85% with significant clinical benefit. The accurate preoperative staging for cancer patients can have a major role in determining the final clinical outcome and in predicting the prognosis. According to the concept of "precision medicine", to achieve "preoperative precision staging of gastric cancer", the application of imaging diagnostic techniques must be combined with the analysis of individual genetic information or tumor molecular pathological classification, which should be based on research of the disease genomics, proteomics and metabolomics. In this article, we provide a review of results on preoperative staging of gastric cancer in recent years, and we also discuss how to think about the "preoperative precision staging of gastric cancer", with special emphasis on the potential of molecular imaging techniques, circulating tumor cells (CTCs) or circulating tumor DNA (ctDNA), molecular targets for tumor targeting therapy and molecular pathological classification, etc. in judging bio-molecular behavior of gastric cancer before surgery.