A clinical trial has found that a prescription form of the omega-3 fatty acid eicosapentaenoic acid (EPA) was associated with longer overall survival among patients undergoing surgery for colorectal cancer that had spread to the liver. The findings offer a new direction for research into supportive treatments for people facing advanced bowel cancer.
The Phase 3 EMT2 trial included 418 patients treated at 13 specialist surgical centres in England and Wales. Participants received either 4 grams per day of high-purity prescription EPA or a placebo, alongside standard cancer care. Treatment began before liver surgery and continued afterwards for up to four years.
Five-Year Survival Was Higher in the EPA Group
Researchers estimated that the five-year overall survival rate was 62% among patients receiving EPA, compared with 45.1% among those given the placebo. The analysis indicated an approximately 32% lower relative risk of death in the EPA group during the study period.
These findings are encouraging because colorectal cancer that spreads to the liver can be difficult to treat, even when surgery is possible. Although removing liver metastases may offer a chance of long-term survival, the disease can return after treatment.
The trial investigated whether adding prescription EPA to standard care could improve outcomes for this group of patients.
The Trial Did Not Meet Its Primary Endpoint
Despite the survival difference, the study did not meet its primary endpoint of progression-free survival, which measures how long patients live without their cancer worsening or returning.
Median progression-free survival was 13.5 months in the EPA group and 12.9 months in the placebo group. This difference was not statistically significant.
The distinction matters because a positive result for overall survival does not automatically mean that a treatment prevents cancer progression. Researchers need further analyses to understand why the survival results differed from the primary outcome.
How EPA Could Affect Cancer Outcomes
EPA is an omega-3 fatty acid that has been studied for its effects on inflammation and other biological processes. Scientists are investigating whether it could influence the body’s response to cancer or affect the environment surrounding tumour cells.
However, the precise reasons for the survival difference remain uncertain. The trial did not establish a definitive biological mechanism, and further research is needed to confirm the findings.
The results also apply to a specific high-purity prescription formulation and dose. They should not be assumed to apply equally to ordinary fish-oil supplements or other omega-3 products.
What the Findings Mean for Patients
The study provides an important result that researchers can investigate further, but it is not yet sufficient to establish EPA as a routine cancer treatment. Additional studies and detailed assessment of the trial results will help determine whether the survival benefit can be reproduced and which patients might benefit most.
Patients receiving treatment for colorectal cancer should continue following their oncology team’s recommendations. They should not start high-dose supplements or change prescribed treatment based on these findings without medical guidance.
Overall, the trial offers a potentially meaningful development in colorectal cancer research while highlighting why both positive findings and study limitations must be considered when evaluating new treatment options.
