Researchers found on Monday that Celebrex, a drug used in the treatment for arthritis, could be used to prevent colorectal cancer. Based on clinical trials, researchers said that Celebrex can reduce pre-cancerous polyps by up to 45%, while also increasing the risk of heart attacks and strokes. People involved in the tests were given 200 or 400-milligram doses of Celebrex 2 a day or placebo and were checked 1 and 3 years later with colonoscopy exams. More than 60% of those who took placebo developed new polyps, while less than half of those taking the drug did. Celebrex belongs to the class of Cox-2 inhibitors, anti-inflammatory drugs that are generally used as arthritis painkillers, and may reduce colorectal benign tumors and also the development of sporadic colorectal tumors. From the same class of Cox-2 inhibitors, Merck's $2.5 billion Vioxx was pulled from the market in 2004 after being shown that it increased risks of heart disease and stroke. 10,000 lawsuits have been filed since then by former patients and their families, blaming the drug for heart attacks and deaths. Pfizer also pulled out its $1.3 billion Cox-2 inhibitor Bextra in 2005, while Celebrex was kept with a revised label containing necessary warnings. Pfizer found in its tests chest pains and cardiovascular events at those who took Celebrex. The company stated he results are consistent with the current warnings on cardiovascular risk in the Celebrex label.