Aspirin Use, Tumor PIK3CA Mutation, and Colorectal-Cancer Survival
- Study type
- Observational study
- Design
- Molecular pathological epidemiology cohort study based on data from two studies, the Nurses' Health Study and the Health Professionals Follow-up Study
- Sample size
- 964 patients
- Source
- N Engl J Med · 2012
In plain words
In this study of people with bowel (colon and rectal) cancer, taking aspirin regularly after diagnosis was linked with living longer only in patients whose tumour had a mutation in the PIK3CA gene. In patients without this mutation, no such link was seen. This study was only observational and does not prove that aspirin improves survival, so do not start taking aspirin without talking to your doctor.
Key results
Treatment arms and regimens
Comparison of regular aspirin use after diagnosis with no regular use. This study is observational and aspirin was not assigned at random. Dose details in the full text.
Comparison of regular aspirin use after diagnosis with no regular use. This study is observational and aspirin was not assigned at random. Dose details in the full text.
Source of the regimen details: Abstract of the paper
Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.
Study population
Patients with colon or rectal cancer from the Nurses' Health Study and the Health Professionals Follow-up Study for whom data on post-diagnosis aspirin use and PIK3CA mutation status (present or absent) were available.
Endpoints
Multivariate hazard ratios for death were calculated with the Cox proportional hazards model, including colorectal cancer-specific survival and overall survival. Tumour markers including PTGS2, phosphorylated AKT, KRAS, BRAF, microsatellite instability, CpG island methylator phenotype and LINE-1 methylation were also examined.
Safety and side effects
Safety data (such as bleeding) are not reported in the abstract.
Clinical significance and place in guidelines
These findings suggest that PIK3CA mutation may be a predictive biomarker of response to adjuvant aspirin, but because the study design is observational, randomised and confirmatory studies are needed to confirm it. No recommendation to change clinical practice can be drawn from the abstract; the status of this topic in current guidelines should be checked.
Limitations
The study design is observational (cohort) and aspirin was not assigned at random; residual confounding and bias are therefore possible. The P value for interaction for overall survival (0.07) was not statistically significant. The number of patients with PIK3CA mutation is not reported in the abstract, but the wide confidence interval in this group indicates uncertainty in the estimate. Further details in the full text.
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.