The possible cancer protective effects (including on pancreatic cancer) of aspirin and related drugs have been actively studied for the past twenty-five years or so. The initial work was noted and especially explored in colon cancer. There is conflicting research but the chemopreventive outcome of long-term aspirin use on cancer seems reasonably likely in colorectal cancer with probable but a lesser likelihood in other parts of the human GI tract. Research on long-term aspirin usage and pancreatic cancer has yielded conflicting results.
The active ingredient in the bark of the willow tree (salicylic acid) was discovered in 1763 by Edward Stone of Oxford University UK. More than one hundred years later, this ingredient was first synthesized by the Bayer company in Germany, the “biotech” high flyer of its day. In modern times, aspirin is categorized in a class called nonsteroidal anti-inflammatory drugs (NSAIDs) that are each separated by slightly different mechanisms of action. The mechanisms of action of aspirin are myriad, but distinctively include being an irreversible cyclooxygenase (“COX”) enzyme inhibitor – both of the COX-1 and COX 2 pathways.
Qin and colleagues from Zhengzhou and Xinxiang, China conducted a meta-analysis of the chemopreventive possibility of aspirin intake in the medical literature and published the results in the January 2014 issue of the journal Pancreas. The authors identified ten studies that met their criteria for analysis which totaled 7,252 patients carrying a diagnosis of pancreatic cancer. They found that the odds ratio of taking a high dosage of aspirin was modestly protective against pancreatic cancer at 0.88. For Americans alone the odds ratio was 0.82. Low dosage intake of aspirin showed no apparent preventive advantage.
The distinction between high dose and low dose of aspirin intake may help explain the previous uneven research results in pancreatic cancer. An interesting result, we will have to watch for follow-up studies to better substantiate these findings.
Dale O’Brien, MD