Long-term use of non-steroidal anti-inflammatory drugs (NSAID) like aspirin and ibuprofen might increase the risk of breast cancer, a study has found. The study, the first to suggest that NSAIDs might increase the risk of breast cancer, has been published in the latest issue of the
Journal of the National Cancer Institute.
According to the study, daily use of aspirin increases risk of estrogen receptor/progesterone receptor (ER/PR)-negative breast tumor, while prolonged daily use of ibuprofen increases the risk of non-localized breast cancer.
The study, by Sarah F Marshall and her team from the University of Southern California, tracked the health of 114,460 women aged between 22 and 85 years, who participated in the California Teachers Study.
All participants were healthy when they joined the study in 1995 and 1996, but in the next six years, 2,391 women were found to have breast cancer.
“We were expecting ibuprofen to reduce risk, and the same for aspirin. These drugs are not preventing breast cancer as earlier studies suggested that they might,” said Sarah Marshall, lead author of the study.
When the regular use of aspirin and ibuprofen, defined as more than once a week, was considered collectively, no link to breast cancer was found. But when the findings were segregated according to the pain reliever or type of breast cancer, researchers found that women who took ibuprofen daily for a period of at least five years had 50 per cent higher chances of being diagnosed with breast cancer than those who did not. In addition, those who took aspirin on a daily basis for at least five years had 80 per cent greater chances of breast cancer, which were not sensitive to estrogen or progesterone, than women who weren’t regular aspirin users.
However, users who took aspirins daily aspirin for a long time showed 20 percent lower chances of developing the more common type of breast tumor, the kind that is sensitive to estrogen and progesterone. But the difference was so small that researchers attributed it to chance.
The study is the first one to indicate heightened risk of cancer due to NSAIDs. Alfred Neugut, a Columbia University researcher who had authored a study that linked the use of NSAIDs to a 20 percent lowered risk of breast cancer, said the new study was ‘totally at odds with every other paper’ released on the same subject.
American Cancer Society researcher Michael Thun was also skeptical about the findings, attributing it to chance. “The findings with regard to colon cancer have been much more persuasive. It is clear that prolonged use of NSAIDs is associated with lower colon cancer risk. But the breast cancer trials have been less convincing,” said Thun, who was involved in a study that found no link between NSAIDs and breast cancer. “However, it underscores concern about the potential toxicities from long-term regular use of these drugs,” he said.
Meanwhile, Marshall said that further research is required before a confirmed link could be established. However, she added, “I’m fairly convinced from our studies that aspirin and ibuprofen are not reducing breast cancer. I would not advise women to take these drugs to prevent breast cancer. But women who are taking them for other good reasons should not stop because of this study.”
Commonly used to treat aches and fever, NSAIDs are taken by some to cut the risk of cardiac ailments.
