Diverse Genomic Signatures Predict Resection Conversion and Survival Outcomes in Patients With Initially Unresectable Colorectal Liver Metastases

All procedures involving human participants in this study adhered to ethical standards set by institutional and/or national research committees, as well as the 1964 Helsinki Declaration and its later amendments or similar ethical standards. This cohort study has been reported in line with the STROCSS criteria.

This study enrolled 286 patients initially diagnosed with colorectal cancer (CRC) concomitant with synchronous liver metastases. All patients received comprehensive treatment and follow-up at the Department of Colorectal Surgery, First Affiliated Hospital of Nanjing Medical University between 2016 and 2018. At diagnosis, all patients met the criteria for preoperative conversion therapy, with a Cancer Recurrence Score (CRS) of ≥3. Patients were excluded if they: i) could not tolerate a full course of systemic therapy; ii) had a history of other malignancies; iii) had previously undergone cancer treatment; or iv) Patients who were not rendered disease-free at time of hepatic resection (i.e., primary intact, unresected extrahepatic disease, or gross [R2] residual hepatic disease) were excluded. Next-generation sequencing (NGS) was conducted on biopsy tissues obtained via colonoscopy prior to treatment initiation, and conversion therapies were subsequently administered. Systemic treatment regimens, based on NGS results, included FOLFOX/FOLFIRI or FOLFOXIRI combined with anti-EGFR or anti-VEGF agents, excluding those who received Selective Internal Radiation Therapy (SIRT) or Stereotactic Body Radiation Therapy (SBRT). All patients were microsatellite stable (MSS) and did not receive any immune checkpoint therapies such as PD-1 inhibitors. Patients with locally advanced rectal cancer received additional neoadjuvant radiotherapy to the rectal area. Treatment response was assessed every two cycles, and resectability of the primary tumor and metastases were evaluated post-treatment using abdominal contrast-enhanced CT and MRI.