The Prognostic Impact of the Number of Colorectal Liver Metastases At the Time of Presentation Among Patients Undergoing Surgery.

BACKGROUND

The prognostic impact of tumor number among surgically treated colorectal liver metastases (CLMs) remains incompletely understood, particularly in patients with extensive disease.

METHODS

We retrospectively analyzed 303 patients who underwent initial hepatectomy for CLMs between 2008 and 2024. Prognostic factors for overall survival (OS) were evaluated using multivariable Cox regression analysis. Estimated mortality hazard at three and five years after surgery was modeled according to the number of liver lesions.

RESULTS

Tumor number (hazard ratio [HR], 1.02; 95% confidence interval [CI], 1.00-1.03; P = 0.025), positive primary nodal status (HR, 1.39; 95% CI 1.04-1.87; P = 0.029), and extrahepatic disease (HR, 1.60; 95% CI, 1.13-2.25; P = 0.007) were independently associated with OS. Mortality hazard gradually increased with increasing tumor number, particularly between 5-30 lesions, although the increase was modest. Among patients with ≥ 10 CLMs, median OS was 39.0 months.

CONCLUSIONS

Tumor number was associated with prognosis after hepatectomy, but increasing tumor burden did not result in a steep increase in mortality hazard. Tumor number alone should not preclude surgical consideration in selected patients.