A US study has indicated that there is a link between regular aspirin use and pancreatic cancer.

These results fly in the face of previous indications that aspiring could protect against cancers of the rectum, stomach and oesophagus (as well as having heart benefits).

90,000 nurses have been followed for 18 years (their lifestyles, diet and diseases they have suffered have been monitored). The findings have been published in the Journal of the National Cancer Research.

Eva Schernhammer, of Brigham and Women's Hospital in Boston (USA), team leader, gleaned through the data for evidence of any link between regular aspiring use and cancer of the pancreas. 161 women had been diagnosed with pancreatic cancer.

Those who took aspirin more than three times a week showed a higher rate of pancreatic cancer (than those who took aspirin less often than three times a week). Those who took aspirin twice or three times a week showed no risk difference from those who never took aspirin.

The data showed that the people who took two regular aspirins a day had an 86% increased risk (however, the team also said that the numbers involved were small).

Bayer (German pharmaceutical company, manufacturers and creators of aspirin) said "the study does not demonstrate a conclusive link between aspirin and pancreatic cancer."

Some experts wondered whether aspirin was the cause of pancreatic cancer or the consequence. If the women in the study had already developed pancreatic cancer they may have been taking aspirin to reduce the pain.

If the two years before diagnosis are omitted from the analysis, the measured risk drops sharply, suggesting that there may be something in this query.