KEY TAKEAWAYS
- The SAKK 41/13 phase III trial verified the benefits of adjuvant aspirin for patients with PIK3CA-mutant colon cancer.
- The primary endpoint was to determine DFS and the secondary endpoints were OS & AEs.
- Aspirin showed a 43% DFS improvement in PIK3CA-mutant colon cancer.
Several retrospective studies suggest a potential protective effect of aspirin as an adjuvant therapy for colon cancer, especially in patients with an activating PIK3CA mutation.
Ulrich Güller and the team aimed to confirm the benefit of adjuvant aspirin in patients with PIK3CA-mutated colon cancer.
This phase III, randomized, placebo-controlled, double-blind trial included stage II and III patients with colon cancer with a centrally assessed PIK3CA mutation in Exon 9 or 20. Patients were randomized 2:1 to receive either 100mg of aspirin daily or placebo for 3 years.
The primary endpoint was disease-free survival (DFS), with secondary endpoints were overall survival (OS) and tracking adverse events (AEs). One-sided type I error was 5% with a power of 80% to detect an HR of <0.456. The study was prematurely closed due to financial constrains.
The results showed that 112 patients were included in the trial, with 74 in the aspirin and 38 in the placebo groups. The median age was 66 [IQR: 29-89], and 42.9% were female.
After a median follow-up of 4 years, there were 19 DFS events. Aspirin showed a DFS hazard ratio (HR) of 0.57 (90% CI: 0.27-1.22, P=0.11) with 3-year DFS rates of 88.3% (90% CI: 80.1-93.3) for aspirin and 82.4% (90% CI: 68.3- 90.7) for placebo. The OS HR was 0.70 (90% CI: 0.23-2.12, P=0.3). No severe aspirin-related AEs were reported.
The study concluded that the SAKK 41/13 trial offers the first prospective evidence of adjuvant aspirin’s protective effect in resected, PIK3CA-mutant colon cancer, showing a 43% improvement in DFS, though statistical significance was limited by sample size.
The trial was sponsored by the Swiss Group for Clinical Research.
Source: https://cslide.ctimeetingtech.com/esmo2024/attendee/confcal/show/session/116
Clinical Trial: https://clinicaltrials.gov/study/NCT02467582
Güller U, Hayoz S, Horber D, et al. (2024). “Adjuvant aspirin treatment in PIK3CA mutated colon cancer patients: The phase III, prospective-randomized placebo-controlled multicenter SAKK 41/13 trial.” Presented at ESMO 2024 (Abstract 512O).
