Ground-breaking study tracked 65,000 older users Regular users of paracetamol have an increased risk of developing blood cancers, researchers have found. The tablets contain a chemical called acetaminophen which has been linked to cases of cancer in a number of individuals who were taking the drug. The findings will terrify the millions in America and worldwide who pop the pills to cure minor ailments without so much as a second thought. Earlier work has shown that aspirin use might lower the odds of dying from colon cancer but increase the risk of bleeding ulcers. The picture has been less clear for blood, or haematologic, cancers, however. The finding adds another twist to the complicated evidence linking cancer and painkillers, and hints acetaminophen might be different from the rest. \'Prior to this study there was very little evidence that aspirin reduces your risk of haematological cancers,\' said Emily White of the Fred Hutchinson Cancer Research Center in Seattle, who worked on the new research. There were some suggestions that acetaminophen might increase the risk of the cancers, on the other hand, but those were based on individual cases of blood cancer. Studies of individual patients aren\'t considered as strong as the new one, which tracked a large population of healthy people over time. \'We have the first prospective study,\' White said. Still, she warned, there is no proof that acetaminophen causes cancer, and the new results need to be confirmed before they are used in any treatment decision.