April 9, 2003 — They are the most exciting drugs for cancer prevention, and chances are you already have them in your medicine cabinet. Aspirin and other antiinflammatory pain relievers, such as ibuprofen, appear to help prevent breast cancer even among high-risk women, according to findings from a major new study. Recent research suggests that people who regularly take aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) have a reduced risk of colon, lung, and even prostate cancers. The latest study is not the first, but it is the largest, to find that the over-the-counter products also prevent breast cancer. The findings were published in the Proceedings of the 2003 annual meeting of the American Association for Cancer Research.
Some 81,000 women between the ages of 50 and 79 taking part in the National Cancer Institute’s Women’s Health Initiative (WHI) were surveyed about their use of aspirin and pain relievers like ibuprofen and acetaminophen. The women were followed for approximately four years, during which time close to 1,400 women were diagnosed with breast cancer. Regularly taking at least two NSAID tablets a week — which doesn’t include acetaminophen — offered breast cancer prevention, regardless of whether or not they were at high risk for breast cancer. Risk was reduced by 21% among women who regularly took any anti-inflammatory drug for five to nine years. Those who took the pain relievers regularly for 10 years or more saw a 28% reduction in risk. The study did not include the newer prescription anti-inflammatory drugs called Cox-2 inhibitors, such as Bextra, Celebrex, and Vioxx. Ibuprofen drugs, such as Advil and Motrin, provided the most breast cancer protection. Women who took standard doses of ibuprofen regularly for 10 years or more reduced their breast cancer risk by almost 50%. However, Tylenol and other acetaminophen-based pain relievers, which have no antiinflammatory properties, offered no breast cancer prevention. Neither did low-dose (81 mg) aspirin. NSAIDs appear to protect against cancer by blocking Cox-2 enzymes, which trigger inflammation and are abundant in most human cancers. The drugs are believed to work in many ways, including blocking cancer cell division and blocking the development of tumor-feeding blood vessels. They may also promote the death of new cancer cells and inhibit their spread. In a press conference, lead researcher Randall Harris, MD, PhD, said it might be time to recommend NSAIDs for breast cancer prevention. But he called for randomized clinical trials to determine the best dose and duration for preventing breast cancer. In addition, studies to determine the effectiveness of the newer class of prescription Cox-2 inhibitors are needed, he adds. Harris says he has taken 200 mg of ibuprofen daily for more than a decade in the belief that he is lowering his risk of cancer. “I am only recommending what I do,” said Harris, professor of epidemiology and biometrics at Ohio State University. “We should wait for clinical studies to make precise recommendations, but at this point I would say women might consider taking [regular] standard doses of one of these compounds as long as they tell their physician about it.”But a breast cancer prevention expert with the National Cancer Institute (NCI) says women should not yet take aspirin, ibuprofen, or any other NSAID to lower their risk of breast cancer. Roughly 1% of people who take them regularly develop stomach and intestinal bleeding, which is serious — and potentially deadly — in about one in 10 people. “Until definitive clinical studies are done we won’t really know if the benefits of taking these drugs for prevention outweigh the risks,” Ernest Hawk MD, MPH, tells WebMD. “So we find ourselves in the unusual position of having cheap, easily available, and widely accepted drugs, but not being able to say if they should be used for this reason.” Hawk is chief of gastrointestinal cancer prevention for the NCI. A similar study, also published in the Proceedings of the AACR meeting, found that low doses of the Cox-2 inhibitor Celebrex may protect against colon cancer when combined with fish oil. In this preliminary study, the combination suppressed cell growth and promoted cell death in a human colon cancer cells. Lead researcher C.V. Rao, PhD, of the Institute for Cancer Prevention says it is likely that a combination of drugs will prove to be more effective than single drugs for preventing certain cancers. (Source: WebMD, Salynn Boyles, 9/4/2003)