Prolonged aspirin use linked to pancreatic cancer in women

Women who take aspirin on a regular basis may be at increased risk for pancreatic cancer, according to a presentation at the American Association for Cancer Research 2nd Annual Frontiers in Cancer Prevention Research Meeting.

But these findings do not mean that women should stop taking aspirin when used as prophylaxis, said Dr. Eva Schernhammer, who presented her group’s findings. “The risks do not outweigh the benefits in reducing the risk for cardiovascular disease,” she told Reuters Health.Dr. Schernhammer and colleagues at Brigham and Women’s Hospital in Boston analyzed data from the Nurses’ Health Study, which includes more than 88,000 women. They had theorized that aspirin would protect against pancreatic cancer, because of its known preventive role in colorectal cancer.During 18 years’ follow-up, 161 cases of pancreatic cancer were documented. Women who reported at least 20 years of aspirin use, averaging two or more tablets per week, had a 58% increased risk of pancreatic risk compared to non-users. There was a dose-response relationship among current, consistent users, with risk increased 11% among those taking one to three tablets/week for a least 4 of 6 consecutive years, versus 86% for those taking 14 or more per week.A plausible explanation for the findings is that aspirin may differentially affect lipoxygenases in various tissues, thus reducing risk for some types of cancer and increasing risk for others. For example, Dr. Schernhammer said, “one study showed that in pancreatic cancer tissue, the procarcinogenic enzyme 5-lipoxygenase mRNA is overexpressed.”Another mechanism, according to case reports and cohort studies, is that “aspirin may be associated with increased risk of pancreatitis, and pancreatitis has been associated with a high pancreatic cancer risk.”Dr. Schernhammer commented that similar cohort studies among men will likely be completed within the next 2 to 4 years.She pointed out that smoking is a far greater risk factor for pancreatic cancer than aspirin. For patients concerned about her group’s findings, physicians should focus on modifiable risk factors for pancreatic cancer, such as smoking cessation and weight reduction.(Source: Reuters Health: Karla Gale: October 27, 2003: Oncolink)