Pancreatic cancer risk from regular aspirin usage

Unlike its protective effects on gastric cancer and the cardiovascular system, the long-term use of aspirin may increase the risk of pancreatic cancer in women, US researchers warn in a study published in the Journal of National Cancer Institute. For their study, the team analyzed data from 88,378 women without cancer enrolled in the Nurses’ Health Study, 161 of whom were diagnosed with pancreatic carcinoma during the 18-year follow-up. Participants were asked about aspirin use at the start of the study, and at 2-year intervals thereafter.

Unlike its protective effects on gastric cancer and the cardiovascular system, the long-term use of aspirin may increase the risk of pancreatic cancer in women, US researchers warn in a study published in the Journal of National Cancer Institute. For their study, the team analyzed data from 88,378 women without cancer enrolled in the Nurses’ Health Study, 161 of whom were diagnosed with pancreatic carcinoma during the 18-year follow-up. Participants were asked about aspirin use at the start of the study, and at 2-year intervals thereafter. Multivariate analyses demonstrated that an increased risk of pancreatic cancer did not correlate with regular use of two or more aspirin tablets per week. Increasing duration of regular aspirin use, however, was associated with a significant increase in cancer risk, lead author Eva Schernhammer (Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts) and colleagues report. Specifically, women who had used aspirin regularly for 20 years or longer were significantly more likely to develop pancreatic carcinoma than those with a shorter history of aspirin use (relative risk [RR]=1.58). Furthermore, women who were identified as using aspirin in at least two of three consecutive biennial questionnaires were found to have an increased risk of pancreatic cancer compared with nonusers that was dependent upon dose. The RR was 1.11 for women using one to three tablets per week, rising to 1.29 for four to six tablets, 1.41 for seven to 13 tablets, and a RR of 1.86 for more than 14 tablets each week. “Our findings do not support a protective effect of analgesic use on the risk of pancreatic cancer,” Schernhammer’s team writes. “Rather, aspirin appears to increase the risk of pancreatic cancer after extended periods of use.” They therefore add: “Risks and benefits associated with the use of aspirin have to be weighed carefully in any recommendations made by healthcare providers.” John Baron (Dartmouth Medical School, Hanover, New Hampshire, USA) commented on the study in a related editorial: “The findings by Schernhammer et al are provocative and force us to think carefully about the actions of aspirin and other nonsteroidal anti-inflammatory drugs and the mechanisms underlying pancreatic cancer. “Fortunately, conflicting data from diverse threads of research are often a very effective push toward scientific progress.”