Clinical significance and changes to the immune microenvironment of colorectal cancer patients with liver metastasis

BACKGROUND: Liver metastasis is common in colorectal cancer patients. Immunotherapy covers a wide range of tumor types and is safer than traditional radiotherapy and chemotherapy. However, its overall effective rate is only 20–40%. At present, there is a lack of relevant research clarifying whether the changes and clinical significance of the immune microenvironment in colorectal cancer patients with liver metastasis are conducive to enhancing the promotion and further improving the efficacy of immunotherapy. METHODS: We retrospectively collected the data of 50 colorectal cancer patients with liver metastasis treated in Chongqing University Cancer Hospital from January 2017 to January 2019. Liver metastatic cancer tissues and normal liver tissues were collected to detect the levels of immune cells in the two samples. At the same time, the correlation between T-cell subsets in the liver metastatic cancer tissue immune microenvironments of colorectal cancer patients and prognosis was analyzed. RESULTS: Compared with the normal liver tissues, the level of T helper cell 1/T helper cell 2 (Th1/Th2) in the liver metastatic cancer tissues was significantly decreased (0.88±0.24 vs. 1.34±0.27, P=0.000), while the levels of regulatory T cells were markedly increased (8.57±2.31 vs. 6.89±1.71, P=0.000). The Th1/Th2 level in liver metastatic cancer tissue exhibited a good predictive value for recurrence and survival 3 years after surgery, and the areas under the curves were 0.783 (95% confidence interval: 0.649–0.916, P=0.002) and 0.763 (95% confidence interval: 0.628–0.898, P=0.001), respectively. Moreover, the regulatory T-cell level in liver metastatic cancer tissue had a good predictive value for recurrence and survival at 3 years postoperatively, and the areas under the curves were 0.788 (95% confidence interval: 0.656–0.919, P=0.002) and 0.763 (95% confidence interval: 0.628–0.897, P=0.001), respectively. CONCLUSIONS: The immunosuppressive condition of liver metastasis in colorectal cancer patients was related to poor prognosis.