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ASCOLT

Aspirin after completion of standard adjuvant therapy for colorectal cancer (ASCOLT)

Phase 3N = 1,587NCT00565708

Population
Patients aged 18 years and older with Dukes' C or high-risk Dukes' B colon cancer, or Dukes' B or C rectal cancer, who had undergone resection and completed standard adjuvant therapy; 1587 randomised between 25 February 2009 and 30 June 2021, 1550 in the modified intention-to-treat analysis (271 Dukes' B colon, 770 Dukes' C colon, 509 rectal).
Design
International, multicentre, phase 3, randomised, double-blind, placebo-controlled trial at 66 centres in 11 countries and territories (ten in Asia-Pacific, one in the Middle East): aspirin 200 mg daily or placebo for 3 years (1:1), followed for 5 years, after completion of standard adjuvant therapy (at least 3 months of chemotherapy). Randomisation stratified by centre, tumour site and stage, and inclusion of oxaliplatin. Primary endpoint disease-free survival; primary analysis by a stratified Cox model in the modified intention-to-treat population (patients commencing study treatment), events to 31 March 2023.
Primary endpoint
DFS
Arms
  • Placebo (control, n = 759): Placebo daily for 3 years (n shown is the modified intention-to-treat analysis)
  • Aspirin 200 mg (experimental, n = 791): Aspirin 200 mg daily for 3 years (n shown is the modified intention-to-treat analysis)
People
Chia JWK
DFSHR 0.91 (95% CI 0.73–1.13)Δ 60-month DFS+2.2 points
Show the numbers
Results reported for ASCOLT
EndpointAnalysisAspirin 200 mgPlaceboEffect
DFSModified intention-to-treat population: patients who started study treatment (1550 of 1587 randomised)primarymedian follow-up 59.2 monthsChia 202577% at 5 y (73.6–80.0%)74.8% at 5 y (71.3–77.9%)HR 0.91 (95% CI 0.73–1.13)P=0.38The authors conclude that aspirin was well tolerated but did not significantly improve DFS. Median follow-up at data cutoff 59.2 months (IQR 36.7-60.0).
Results reported for ASCOLT
EndpointAnalysisAspirin 200 mgPlaceboEffect
DFSModified intention-to-treat population: patients who started study treatment (1550 of 1587 randomised)primarymedian follow-up 59.2 monthsChia 202577% at 5 y (73.6–80.0%)74.8% at 5 y (71.3–77.9%)HR 0.91 (95% CI 0.73–1.13)P=0.38The authors conclude that aspirin was well tolerated but did not significantly improve DFS. Median follow-up at data cutoff 59.2 months (IQR 36.7-60.0).
Hazard ratio (95% CI) by endpoint. Values below 1 favour the experimental arm.
DFS0.512◀ experimentalcontrol ▶
Data table
EndpointHR95% CI
DFS0.910.73–1.13
Primary publication: Chia JWK, Segelov E, Deng Y, Ho GF, Wang W, Han S, et al. Aspirin after completion of standard adjuvant therapy for colorectal cancer (ASCOLT): an international, multicentre, phase 3, randomised, double-blind, placebo-controlled trial. Lancet Gastroenterol Hepatol. 2025;10(3):198-209. PubMedDOI

Appears in

Sources

  1. Chia JWK, Segelov E, Deng Y, Ho GF, Wang W, Han S, et al. Aspirin after completion of standard adjuvant therapy for colorectal cancer (ASCOLT): an international, multicentre, phase 3, randomised, double-blind, placebo-controlled trial. Lancet Gastroenterol Hepatol. 2025;10(3):198-209.

    PubMedDOI