Low-dose Aspirin Use Has Potential to Lower Pancreatic Cancer Risk

In a retrospective study funded by the National Cancer Institute and conducted by researchers from the Yale School of Public Health, low-dose aspirin use was found to be associated with lower risk for developing pancreatic cancer and the longer an individual used aspirin correlated with increasingly lower risk.

In the study, released June 26, 2014 in the journal Cancer, Epidemiology, Biomarkers & Prevention, researchers recruited study participants from 30 general hospitals in Connecticut between 2005 and 2009.¹ Their sample included 362 patients with pancreatic cancer and 690 controls. Data on aspirin use, smoking history, body mass index, and other risk factors were obtained in face-to-face interviews. Daily aspirin doses of 75 mg to 325 mg, usually for cardioprotection, were considered low-dose, and higher doses, most commonly used for other purposes (eg, pain or fever), were considered regular dose. More than 9 of 10 participants reported daily aspirin use. 

RELATED: Pancreatic Cancer Resource Center

Both men and women who used low-dose aspirin regularly had an overall 48% reduction in pancreatic cancer risk (odds ratio [OR] = 0.52; 95% CI, 0.39-0.69).¹  “We found that the use of low-dose aspirin was associated with cutting the risk of pancreatic cancer in half, with some evidence that the longer low-dose aspirin was used, the lower the risk,” said Harvey Risch, MD, PhD, who is an author of the study and professor of epidemiology in the Department of Chronic Disease Epidemiology at the Yale School of Public Health. Each additional year using low-dose aspirin was associated with an incremental decrease in pancreatic cancer risk (OR=0.94; 95% CI, 0.91-0.98).¹ “Because about 1 in 60 adults will get pancreatic cancer and the 5-year survival rate is less than 5%, it is crucial to find ways to prevent this disease,” he explained.

The results of the present study further illuminate the findings of several earlier studies that have associated regular aspirin use with reductions in pancreatic cancer risk and mortality. A retrospective, case-control study from the Mayo Clinic found that regular use of aspirin for cardioprotection or other purposes, but not use of acetaminophen or nonsteroidal anti-inflammatory drugs, correlated with significantly lower risk for developing pancreatic cancer. Risk reductions were observed with 1 day or more versus less than 1 day of aspirin use and using aspirin 2 days or more per week versus 1 to 4 days per week.² Data from the Cancer Prevention Study II Nutrition Cohort (N=100,139) revealed that daily aspirin use versus no use was associated with slightly lower cancer mortality, including modest but not significant reductions in pancreatic cancer mortality.³

RELATED: Aspirin for Colorectal Cancer Prevention

Interestingly, a meta-analysis of 10 studies including 7,252 cases of pancreatic cancer and more than 120,000 healthy controls, published earlier this year, found that use of high-dose—but not low-dose—aspirin was associated with lower risk for pancreatic cancer (relative risk = 0.88; 95% CI, 0.76-1.01).⁴ Dr. Risch explained that only recently have people been using daily low-dose aspirin for cardioprotection for durations sufficient to affect their risk of pancreatic cancer development. “There seems to be enough evidence that people who are considering aspirin use to reduce the risk for cardiovascular disease can feel positive that their use might also lower their risk for pancreatic cancer, and quite certainly wouldn’t raise it,” he added. Extended use of aspirin is associated with potential risks of its own, which must be weighed in any risk to benefit analysis. Putting this in context, Dr. Risch explained that “for the small subset of individuals with strong family histories of pancreatic cancer or who otherwise have been evaluated to be at substantially increased risk of pancreatic cancer, aspirin use could be part of a regimen designed to reduce their risk.”

References

1. Streicher SA, Yu H, Lu L, et al. Case-control study of aspirin use and risk of pancreatic cancer. Cancer Epidemiol Biomarkers Prev. 2014;23(7):1-10.
2. Tan XL, Lombardo KMR, Bamlet WR, et al. Aspirin, nonsteroidal anti-inflammatory drugs, acetaminophen, and pancreatic cancer risk: a clinic-based case–control study. Cancer Prev Res. 2011;4(11):1835-1841.
3. Jacobs EJ, Newton CC, Gapstur SM, Thun MJ. Daily aspirin use and cancer mortality in a large US cohort. J Natl Cancer Inst. 2012;104(16):1208-1217.
4. Cui XJ, He Q, Zhang JM, et al. High-dose aspirin consumption contributes to decreased risk for pancreatic cancer in a systematic review and meta-analysis. Pancreas. 2014;43(1):135-140.