Beginning in the 1980s, numerous uncontrolled (observational) studies have indicated a potential benefit of certain painkillers for reducing the risk of colorectal cancer (CRC). The drugs are known as NSAIDs (pronounced EN-seds), or nonsteroidal anti-inflammatory drugs. They are among the most commonly prescribed and purchased OTC medications, and the group includes Aleve, ibuprofen (Motrin, Advil), Celebrex, Voltaren (diclofenac), among others. Aspirin is another.
Now a large, new Danish study again not prospectively controlled, but rather a retrospective case-control study has lent further support to the NSAID-CRC literature. Researchers from the Department of Clinical Epidemiology at Aarhus University Hospital compared medication history from 103,000 Danes with no history of CRC, with those of 10,300 CRC patients. They found that people taking non-aspirin NSAIDs continuously for five years or longer had a 30-45% reduced incidence/risk of CRC (compared to those not on such drugs, or taking them intermittently or for a shorter time); those taking low-dose aspirin continuously (75-150 mg) for five years or longer had a 27% reduced incidence of CRC. The largest risk reductions came from NSAIDs that targeted COX-2 (cyclooxygenase-2) specific enzymes for inflammation and pain (mainly Celebrex).
Lifestyle factors such as diet, weight and exercise were not measured, nor were possible harms related to taking the NSAIDs studied at all. The study was published in this week's Annals of Internal Medicine.
CRC is the third most common cancer in the U.S., behind lung and prostate cancer in men, and lung and breast cancer in women. It is the second leading cause of cancer death. About nine out of 10 people diagnosed with CRC are at least 50-years old. Forty percent of Americans aged 50 years and over have benign tumors in the colon; it is estimated that 2% will progress to cancer. As this form of cancer is especially slow to develop, it is a good candidate to have its incidence reduced by successful preventive actions such as taking low-dose aspirin or NSAIDs.
However, it should be emphasized that we still do not have a "gold standard," prospective, randomized controlled study of NSAIDs proving that they reduce CRC risk so it would be foolish to rely on them for protection. The best way to reduce your risk of CRC is colonoscopy as recommended by the American Gastroenterological Association, with most folks getting an initial study at age 50 and at intervals thereafter.
Also, note that NSAIDs are not entirely safe for all. Their most unpleasant side effect is GI distress, which can include actual bleeding. And avid Dispatch readers will recall that it was not long ago that we published this item on July 10: we pointed out that the FDA tightened its warning about NSAIDs causing heart ailments (not including aspirin). So discuss these risks and benefits with your own doctor before embarking on an NSAID chemoprevention regimen.