Outcomes of Simultaneous Versus Staged Resection for Stage IV Colorectal Cancer with Synchronous Liver Metastases.

INTRODUCTION: Management of stage IV colorectal cancer with synchronous liver metastases remains debated, as colorectal and liver resections can be performed simultaneously or staged apart.

OBJECTIVE: This study aims to determine any demographic or outcome differences between simultaneous and staged resection.

PARTICIPANTS: Retrospective review was performed on patients diagnosed with synchronous colorectal primary and liver metastases within Southern California Kaiser Permanente (KP) hospitals between 2010 and 2020. Patients with other metastases on diagnosis or those who did not receive both primary and liver resections were excluded. Demographic and outcome data were collected and analyzed.

RESULTS: Of the 113 patients who met criteria, 72 (63.7%) received simultaneous and 41 (36.3%) received staged resection. Demographic data were comparable between simultaneous and staged resection, respectively, including median age of diagnosis, sex, and race. Both groups had similar median length of stay, percentage of major colorectal resection, and percentage of major liver resection. Both groups also had similar rates of radiation therapy, chemotherapy, and immunotherapy. There were no statistically significant difference in complications rates, median follow-up time, median overall survival, and median disease-free survival.

CONCLUSIONS: Practice patterns within Southern California KP hospitals favor minor colorectal and liver resections. However, there were no significant differences in demographics, treatment rates, or outcomes between simultaneous and staged resection. While not statistically significant, our findings of a 11.9% higher major liver resection rate and 7.5-month longer median disease-free survival in the staged resection group may benefit from further study with higher power datasets.