Researchers say they have found that high doses of the arthritis drug Celebrex reduced the number of pre-cancerous growths in the colon.
Celebrex is produced by drug company Pfizer.
Two large investigational trials, the Adenoma Prevention with Celecoxib (APC) trial, funded by the National Cancer Institute and Pfizer, and the Prevention of Sporadic Adenomatous Polyps (PreSAP) trial, funded by Pfizer, have both found that sustained, higher doses of Celebrex for almost three years reduced pre-cancerous polyps (adenomas) with the greatest benefit for those at highest risk of polyp recurrence.
Both trials enrolled patients who had already had precancerous colon polyps removed. They were about 60 years old, on average, at the start of the trial; the majority had cardiovascular risk factors such as high blood pressure, diabetes, angina, previous heart attacks, strokes or were smokers.
Pre-cancerous polyps, if left undetected and untreated, can grow into full-blown colon cancer and spread.
In the PreSAP trial, 34 out of 100 patients on Celebrex 400 mg developed pre-cancerous polyps over the three-year study period, compared to 49 out of 100 receiving no medication (placebo). In the APC study, 42 out of 100 on the 400 mg dose and 37 out of 100 on the 800 mg dose of Celebrex developed pre-cancerous polyps, compared to 61 out of 100 patients receiving no medication. Overall this represents up to a 45 percent reduction in the development of pre-cancerous polyps.
However the researchers say the ongoing concerns about heart risks and COX-2 inhibitors make any recommendation for it's use, premature.
The scientists say more study is needed to determine if taking Celebrex daily for years is advisable for some patients who face a high risk of developing colon cancer.
Celebrex belongs to the same class of drugs as Vioxx, produced by drug company Merck, which was withdrawn from the market in 2004 because of a link to heart attacks and strokes.
Both drugs work by inhibiting the COX-2 enzyme involved in inflammation.
The researchers say Celebrex clearly helps to reduce the number of benign growths called adenomas in the colon.
Celebrex carries a warning that the drug and other pain relievers known as non-steroidal anti-inflammatory drugs may increase the chances of developing possibly fatal cardiovascular problems.
Pfizer is funding a separate study designed to determine the heart risks of Celebrex compared to other pain relievers.
Scientists believe COX-2 inhibitors may help ward off certain cancers because the diseases are linked to inflammation. COX-2 is one component of inflammation.