A team from Michigan and California, USA, examined the role of aspirin as an adjunct to or a substitute for colorectal cancer screening, and its cost-effectiveness.
The researchers analyzed data on colorectal cancer epidemiology, screening, costs, and aspirin chemoprevention in the general US population between 1980 and 1999.
Aspirin therapy was analyzed in patients screened with sigmoidoscopy every 5 years and fecal occult blood testing every year (FS/FOBT), or colonoscopy every 10 years (COLO).
A 30% reduction in colorectal cancer risk was assumed in a base-case analysis of subjects taking aspirin. It was found that aspirin increased costs and decreased life-years because of related complications as an adjunct to FS/FOBT.
As an adjunct to COLO, aspirin cost $149,161 per life-year gained.
| Improvements in screening adherence needed, even in those already taking aspirin.
| Annals of Internal Medicine |
In patients already taking aspirin, screening with FS/FOBT or COLO cost less than $31,000 per life-year gained.
A sensitivity analysis found that cost-effectiveness estimates depended highly on the magnitude of colorectal cancer risk reduction with aspirin. They also depended on aspirin-related complication rates and the screening adherence rate in the population.
However, when the model's inputs were varied over wide ranges, aspirin chemoprophylaxis remained generally non-cost-effective for patients who adhere to screening.
Dr Uri Ladabaum, of the University of California, San Francisco, said on behalf of fellow authors, "In patients undergoing colorectal cancer screening, aspirin use should not be based on potential chemoprevention.
"Aspirin chemoprophylaxis alone cannot be considered a substitute for colorectal cancer screening."
"Public policy should focus on improving screening adherence, even in patients who are already taking aspirin," it was concluded.