High‑intensity focused ultrasound thermal ablation boosts the efficacy of immune checkpoint inhibitors in advanced cancers with liver metastases: A single‑center retrospective cohort study.

High-intensity focused ultrasound thermal ablation (HIFU) is a novel non-invasive technique in the treatment of liver metastases (LIM) that allows focal destruction and is not affected by dose limits. This retrospective study aimed to explore the efficacy of HIFU in improving survival and the safety of the method in newly diagnosed patients with cancer with LIM who received first-line immune checkpoint inhibitor (ICI) therapy. Between January 2018 and December 2023, data from 438 newly diagnosed patients with cancer and LIM who were treated at Mianyang Central Hospital (Mianyang, China) were reviewed. A total of 94 patients were enrolled in this study, of whom 28 were diagnosed with lung carcinoma, 36 with gastric carcinoma, 11 with esophageal carcinoma, 7 with cholangiocarcinoma and 12 with other malignancies. The patients were divided into groups depending on whether they underwent HIFU. Progression-free survival (PFS), overall survival (OS) and adverse events (AEs) were compared. Clinicopathological features were analyzed using the chi-squared test. Of the 94 patients, 28 received ICI + HIFU as first-line treatment. After a median follow-up of 13.8 months, the median PFS and OS in the HIFU group were 2.38 times [10.95 . 4.60 months, 95% confidence interval (CI): 1.087-3.106, P<0.0001] and 1.84 times (19.6 . 10.67 months, 95% CI: 1.087-3.106, P=0.0418), respectively, higher than in the group without HIFU. All-cause AEs and immune-mediated AEs were similar between the groups with and without HIFU. However, the incidence of grade 1-2 immune-mediated AEs, troponin elevation, hepatotoxicity and renal dysfunction were more common in the current patients with LIM than those reported previously for the entire population. No immune-mediated AEs of grade ≥3 occurred in either group. HIFU prolonged the PFS and OS of first-line ICI in newly diagnosed patients with advanced cancer with LIM, with manageable safety and tolerability. The efficacy of HIFU in patients with LIM who plan to undergo ICI treatment warrants further prospective clinical investigation.