# The Efficacy and Safety of Hepatic Arterial Infusion Chemotherapy for Mismatch Repair Proficient (pMMR)/Microsatellite Stable (MSS) Colorectal Cancer Liver Metastases (CRLM)

## TL;DR

This study evaluates the effectiveness and safety of hepatic arterial infusion chemotherapy for treating colorectal cancer liver metastases in patients unresponsive to standard treatments.

## Contribution

The study provides new evidence on the efficacy and safety of HAIC in pMMR/MSS CRLM patients resistant to systemic therapy.

## Key findings

- HAIC achieved a median progression-free survival of 5.10 months and overall survival of 16.80 months.
- Combining HAIC with targeted therapy did not significantly improve outcomes compared to HAIC alone.
- No severe adverse events were observed, indicating HAIC is well-tolerated.

## Abstract

To assess the effectiveness and safety of hepatic arterial infusion chemotherapy (HAIC) in patients with mismatch repair proficient (pMMR)/microsatellite stable (MSS) colorectal cancer liver metastases (CRLM) who are resistant to standard treatments.

This study retrospectively evaluated 137 consecutive patients with pMMR/MSS CRLM who underwent HAIC from July 2019 to September 2023. Progression‐free survival (PFS) was the primary outcome, with secondary outcomes being overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety. The Cox proportional hazards model was used to identify prognostic factors for survival.

In total, 78 patients participated, with a median age of 58 years (IQR, 50.75–64.00), and 50 were male. Among these, 28 were treated with a combination of HAIC and targeted therapy, whereas 50 were given HAIC monotherapy. For all patients, the median PFS and OS were 5.10 months (95% CI: 2.85, 7.35) and 16.80 months (95% CI: 13.07, 20.53), respectively. The ORR and DCR for intrahepatic lesions were 1.37% and 58.9%, respectively. All lesions had an ORR of 2.74% and a DCR of 30.14%. The 1‐year OS rate was 67.63 (95% CI, 57.22, 79.91). Patients undergoing HAIC, whether with or without targeted therapy, showed no significant differences in ORR and DCR. Multivariable analysis showed that the combination of HAIC and targeted therapy was not an independent risk factor for PFS and OS. No adverse events of grade 4 or higher were observed.

HAIC shows effectiveness and tolerance in pMMR/MSS CRLM patients who are refractory to systemic therapy. However, the additive value of targeted therapy for HAIC in these patients needs to be further investigated.