Individuals who began taking low-dose aspirin before they were diagnosed with colorectal cancer were reported to have longer survival times than patients who did not take this drug.
Dr Chris Cardwell and colleagues from Northern Ireland investigated survival times of patients who begin taking low-dose aspirin after a diagnosis of colorectal cancer in a large population-based cohort study.
The research team performed a nested case-control analysis using a cohort of 4794 patients diagnosed with colorectal cancer from 1998 through 2007, identified from the UK Clinical Practice Research Datalink and confirmed by cancer registries.
|There was no association between low-dose aspirin usage and colon cancer−specific mortality|
There were 1559 colorectal cancer−specific deaths, recorded by the Office of National Statistics, and these were each matched with up to 5 risk-set controls.
The team used conditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI), based on practitioner-recorded aspirin usage.
Overall, low-dose aspirin use after a diagnosis of colorectal cancer was not associated with colorectal cancer−specific mortality or all-cause mortality.
A dose−response association was not apparent, for example, low-dose aspirin use for more than 1 year after diagnosis was not associated with colorectal cancer−specific mortality.
The researchers found no association between low-dose aspirin usage and colon cancer−specific mortality or rectal cancer−specific mortality.
Dr Cardwell's team concludes, "In a large population-based cohort, low-dose aspirin usage after diagnosis of colorectal cancer did not increase survival time."