Simultaneous Resection of Liver Metastasis With CRC Linked to Better Survival Rates

Perioperative complication rates did not differ in simultaneous vs delayed resection of colorectal cancer (CRC) and synchronous liver metastasis (SLM), and survival benefits of simultaneous resection were limited to patients with Kirsten rat sarcoma (KRAS) wild-type tumors, according to a study in JAMA Network Open.

Participants in the comparative effectiveness research study underwent a curative-intent operation for colorectal liver metastasis between January 1, 2000, and December 31, 2019, and had genetic data retrospectively identified from 3 independent centers in China. The primary outcome was the percentage of patients with at least 1 major complication within 60 days postoperation for CRC and/or SLM.

A total of 1057 patients (men, 68.0%; mean age, 57.4±11.2 years) underwent delayed resection, and 512 patients (men, 60.5%; mean age, 57.1±10.5 years) underwent simultaneous resection.

The percentage of perioperative complications within 60 days of surgery was not statistically different in participants who received simultaneous resection or delayed resection for CRC after corresponding unbiased estimates (34.1% vs 30.0%; P =.89).

The median follow-up was 72.3 (range, 6.2-179.3) months in the delayed resection group and 74.5 (range, 17.9-188.2) months in the simultaneous resection group. Overall survival (OS) rates were 67.5% at 3 years, 46.4% at 5 years, and 33.5% at 8 years for the delayed resection group, compared with 78.7%, 64.4%, and 63.3%, respectively, for the simultaneous resection group (hazard ratio [HR], 1.50; 95% CI, 1.21-1.88; P <.001).

The cancer-specific survival (CSS) rates were 69.8% at 3 years, 50.9% at 5 years, and 39.1% at 8 years for the delayed resection group vs 79.5%, 67.2%, and 65.8%, respectively, in the simultaneous resection group (HR, 1.45; 95% CI, 1.14-1.86; P =.003).

After propensity score matching, 495 pairs of patients for the OS analysis and 450 pairs for the CSS analysis were available. A statistically significant difference in outcomes in the delayed resection group vs the simultaneous resection group was observed for OS (65.2% at 3 years, 47.1% at 5 years, and 38.0% at 8 years for the delayed resection group and 78.0%, 65.4%, and 63.1%, respectively, for the simultaneous resection group, P <.001) and for CSS (68.3% at 3 years, 48.5% at 5 years, and 37.1% at 8 years for the delayed resection group and 79.2%, 67.2%, and 65.9%, respectively, in the simultaneous resection group, P <.001). Simultaneous resection was independently associated with improved OS (HR, 1.42; 95% CI, 1.10-1.85; P =.003) and CSS rates (HR, 1.50; 95% CI, 1.14-1.98; P =.004).

Among patients with KRAS wild-type tumors, propensity score matching resulted in 150 pairs of patients for the OS analysis and 139 pairs for the CSS analysis. Simultaneous resection vs delayed resection was associated with a longer OS rate (5-year OS, 45.7% vs 78.0%; HR, 1.61 [95% CI, 1.45-2.18; P <.001]) and CSS rate (5-year CSS, 50.0% vs 78.7%; HR, 1.62 [95 CI, 1.40-1.87; P =.003]).

In patients with overall KRAS sequence variation, outcomes were not statistically different in those who had simultaneous liver resection vs those who underwent delayed liver resection.

Study limitations include the retrospective design, and unidentified biases may have occurred in favor of the simultaneous resection group. Also, extended RAS sequence variation beyond KRAS sequence variations and other factors were not included due to limited data availability.

“It is acceptable for patients presenting with CRC and resectable SLM to undergo simultaneous resection of the primary tumor and the liver metastases,” the researchers wrote. “Integrating molecular features in the choice of treatment before surgery provides a theoretical basis for more accurate individualized treatments.”