Consideration on immunotherapy of liver metastases of malignant tumors

In this editorial, we comment on the article "Analysis of the impact of immunotherapy efficacy and safety in patients with gastric cancer and liver metastasis" by Liu et al that was published in the recent issue of the World Journal of Gastrointestinal Surgery. It has prompted us to think and summarize some thoughts on immunotherapy for malignant tumor liver metastasis. Immunotherapy plays a crucial role in the treatment of malignant tumors; however, the presence of liver metastases in advanced tumors may impact its efficacy. Although patients with liver metastases can still benefit from immunotherapy, multiple clinical studies have indicated that, compared to other sites of metastasis, liver metastases may diminish the effectiveness of immunotherapy. The efficacy of immune checkpoint inhibitors in patients with liver metastases often fails to reach the ideal level, primarily due to the liver metastases exploiting the host's peripheral immune tolerance mechanisms to promote systemic CD8(+) T cell exhaustion, resulting in a systemic immune-tolerant environment. This article aims to summarize the reasons for the decreased efficacy of immunotherapy following liver metastasis in various malignant tumors and propose potential clinical strategies for management.