160P - Clinical observation and immune effects of high-intensity focused ultrasound (HIFU) in the treatment of liver metastasis in colorectal cancer

Background

To analyzes the clinical efficacy and immune impact of high-intensity focused ultrasound treatment on patients with liver metastasis of colorectal cancer.

Methods

(1) A total of 64 patients with liver metastasis from CRC who received HIFU ablation at the Affiliated Hospital of Qingdao University were retrospectively analyzed. The effects of the number of systemic treatment lines on the progression-free survival and survival time of patients were investigated. (2) Among 64 patients, a propensity score matching cohort study was used to match the corresponding first-line system treatment group patients. (3) Immunohistochemical staining was performed on the liver cancer tissue of 6 patients before and after HIFU treatment (CD8 CD68, FOXP3, PD-L1, IL-6, MMR).

Results

(1) Sixty-four patients received a total of 69 courses of HIFU treatment for liver metastasis. The median survival time of 64 patients with liver metastasis from CRC after receiving HIFU treatment was 52 months. (2) The number of liver metastases receiving HIFU treatment and the number of systemic treatment lines had significant effects on patient survival (P<0.05). (3) After propensity score matching between the HIFU +systematic group and the systematic group for CRLM, there was no difference in PFS between the two groups; the OS of patients in the HIFU + systematic group was significantly better than that in the systematic group (P <0.0001).(4)Compared with liver metastatic cancer tissue before HIFU treatment, CD8 expression increased, CD68 expression decreased, FOXP3 expression decreased, IL-6 expression decreased, 1/3 PD-L1 expression increased, and 1/4 pMMR type changed to dMMR type in liver metastatic cancer tissue after HIFU treatment.

Conclusions

The combination of standard treatment and HIFU treatment for CRC with liver metastasis prolongs overall survival time. After HIFU treatment, the tumor can better stimulate the tumor immune response, which transforms "cold" tumors into "hot" tumors and improves the tumor immune microenvironment. This provides direction for future immunotherapy of liver metastasis in CRC.

Editorial acknowledgement

Clinical trial identification

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.