Aspirin treatment did not reduce the risk of recurrence or death among patients treated for liver metastases from colon and rectal cancer. This is shown by a study involving researchers from Karolinska Institutet, published in The Lancet Gastroenterology & Hepatology.
Colon and rectal cancer often spread to the liver. In some patients, the metastases can be surgically removed or destroyed using local treatment with the aim of curing the disease. Despite this, the cancer often returns. The researchers therefore wanted to investigate whether aspirin treatment could reduce the risk of recurrence.
Patients followed for up to three years
The study included 428 patients at 14 hospitals in Norway, Sweden and Denmark. After completing treatment for their liver metastases, the participants were randomly assigned to receive either 160 milligrams of aspirin or a placebo, a tablet containing no active substance, every day for up to three years. Neither the patients nor the researchers knew which treatment each participant received during the study.
The results showed no improvement in disease-free survival, meaning the length of time until recurrence or death.
"Unlike the important findings from the ALASCCA study last year, the results of this study do not support the routine use of aspirin after curative-intent treatment of liver metastases from colon and rectal cancer," says Ernesto Sparrelid , adjunct professor at the Department of Clinical Science, Intervention and Technology .
Lower survival in the aspirin group
After three years, 76 per cent of the patients in the aspirin group and 85 per cent of those in the placebo group were alive. The researchers emphasise that survival was a secondary outcome and that the study was not designed to provide a definitive answer to this question. The result should therefore be interpreted with caution.
Serious adverse events were also more common among patients receiving aspirin. Such events occurred in 8 per cent of patients in the aspirin group and 2 per cent of those in the placebo group. No deaths were considered to have been caused by the study treatment.
Findings do not support routine treatment
"Although aspirin has been shown to reduce recurrence rates in patients who have undergone surgery for a primary tumour in the colon or rectum, its effects still need to be evaluated in the specific patient group for which it is intended, in this case patients with colorectal cancer that has spread to the liver. We found no clear benefit in this group, while serious adverse events were more common," says Ernesto Sparrelid.
The study was conducted at specialist hospitals in Norway, Sweden and Denmark. The principal investigator was Professor Sheraz Yaqub at Oslo University Hospital. The study was funded by the Research Council of Norway, the Norwegian Cancer Society, the Norwegian programme Therapy Research in the Specialist Health Services and the Oslo University Hospital Foundation. The funders had no role in the conduct or reporting of the study.
Publication
" Aspirin after curative-intent treatment of colorectal cancer liver metastases (ASAC): a multicentre, phase 3, randomised, double-blind, placebo-controlled trial ", Yaqub S, Valberg M, Bjørnbeth B et al.The Lancet Gastroenterology & Hepatology, online 23 September 2026, doi: 10.1016/S2468-1253(26)00260-8.
