Liver metastasis from gastric cancer is one of the difficulties in the clinical treatment of advanced gastric cancer, and its treatment options are still inconclusive. More traditional conservative treatment has limited impact on its prognosis, and multidisciplinary and individualized treatment based on surgery has become the main treatment option in recent years. At present, surgical resection of primary gastric cancer and liver metastases has achieved good results, so strict control of surgical indications has become crucial. In this article, we will discuss the progress and controversies in the surgical treatment of liver metastases from gastric cancer. Gastric cancer is the 4th most prevalent malignancy and the 2nd most deadly malignancy worldwide. Due to cost-effectiveness and population size issues, gastric cancer is not routinely screened for in most countries, and most patients with gastric cancer are already in the progressive stage when diagnosed. The overall incidence of liver metastases from gastric cancer is about 4% to 14%. Depending on the time of appearance of liver metastases, they can be divided into: simultaneous liver metastases and heterochronic liver metastases. Among all patients who underwent radical surgery for gastric cancer, the incidence of simultaneous or heterochronic liver metastases is about 5%-15%. The appearance of liver metastases from gastric cancer indicates that the tumor has reached an advanced stage, and without relevant treatment, the prognosis is extremely poor, with a median survival of less than 6 months and a 5-year survival rate of less than 10%. Currently, there is no standard treatment plan for liver metastasis of gastric cancer. The National Comprehensive Cancer Network (NCCN) and the Japanese Guidelines for the Treatment of Gastric Cancer only recommend palliative treatment such as systemic chemotherapy, tumor-reducing surgery and supportive therapy for patients with stage M1 gastric cancer who have liver metastasis.
With the development of medical technology, the treatment of advanced tumors no longer remains at the primary stage of treatment, and some more aggressive and effective treatment methods are more often adopted. The more aggressive treatment modes for liver metastases of gastric cancer include surgical resection, systemic chemotherapy and local treatment (e.g. high-intensity focused ultrasound for liver metastases, radiofrequency ablation of liver metastases, microwave curing, hepatic artery infusion embolization chemotherapy, etc.). Some scholars also believe that non-surgical treatment has no substantial improvement on prognosis, and “radical” surgery is the only chance for long-term survival of patients with liver metastases from gastric cancer, thus, whether patients with liver metastases from gastric cancer should receive surgical treatment has become a hot topic of debate in recent years. Gastric cancer liver metastases that can be surgically resected “curative” surgery for gastric cancer liver metastases refers to the combination of D2 radical surgery of gastric primary foci and R0 resection of liver metastases. No matter simultaneous or heterochronic liver metastases, surgery can be considered when the conditions are suitable. Based on years of experience in treating liver metastases of gastric cancer in our hospital, the author believes that: 1. Only on the basis of radical surgery of primary foci, liver metastases can be resected at the same time to benefit patients’ survival; 2. The conditions for “curative” surgery are: simultaneous liver metastases of gastric cancer without extrahepatic metastases, primary foci of heterochronic liver metastases of gastric cancer D2 radical surgery can be performed; liver metastases are technically feasible for R0 resection (single metastases ≤ 4
cm in diameter, multiple metastases confined to the hemihepatic region, involving the right and left hepatic lobes but the total number of metastases does not exceed 3), and the residual liver has sufficient compensatory reserve. Gastric cancer liver metastases that cannot be surgically resected Each treatment method has its specific limitations, and only 10% of patients with gastric cancer liver metastases choose surgical resection. This is mainly related to the specific biological characteristics of gastric cancer liver metastases, such as multiple and scattered liver metastases, or liver metastases combined with peritoneal metastases, lymph node metastases, extrahepatic metastases, and even surrounding organ invasion. According to some studies, the surgical treatment of liver metastases from colorectal cancer can be applied to four or even more metastases, but not to gastric cancer, mainly because liver metastases from gastric cancer are more likely to be combined with extrahepatic metastases and often have micro-metastases than liver metastases from colon cancer. Therefore, for patients with more than 3 sporadic metastases, metastases larger than 5 cm in diameter or in special locations, invasion of peripheral organs, peritoneal implantation metastases, distant lymph node metastases and metastases to other organs outside the liver, current research shows that blind surgical resection cannot benefit them, and active and effective comprehensive treatment can improve their survival rate. Summary The treatment of liver metastases from gastric cancer still lacks a clear guideline protocol. In recent years, advances in surgical treatment have provided a ray of hope for the “cure” of patients with liver metastases from gastric cancer, but there are still controversies in the medical community as to whether they should receive surgical treatment and the indications for surgery. Comprehensive multidisciplinary discussion, adequate evaluation before treatment, strict control of surgical indications and individualized treatment plan are still the most important factors to prolong patients’ survival and improve their quality of life at this stage.