MONDAY, Nov. 29 (HealthDay News) -- The prescription painkiller Celebrex might help prevent non-melanoma skin cancers, a small study suggests.
But one expert was quick to note that the drug, which is most commonly used to counter the pain of arthritis, has been linked in some studies to an increase in the risk for cardiovascular problems. So it isn't yet clear that Celebrex (celecoxib) is an ideal choice to prevent cancers that could be treated by other means.
"We have a lot of different treatments for non-melanoma skin cancers," noted Dr. Doris Day, a dermatologist at Lenox Hill Hospital in New York City. "I would want more information regarding the mechanism of action of Celebrex, because of the other risks," she said.
The report, funded by the U.S. National Cancer Institute and Pfizer, the maker of Celebrex, is published in the Nov. 29 online edition and the Dec. 15 print issue of the Journal of the National Cancer Institute.
Non-melanoma skin cancers are common, comprising "the most prevalent malignancies in the United States with an incidence equivalent to all other cancers combined," according to study lead author Dr. Craig A. Elmets, a professor of dermatology at the University of Alabama at Birmingham. These tumors include basal cell and squamous cell carcinomas of the skin, which are typically linked to overexposure to UV rays from the sun or indoor tanning booths.
Currently, there are no U.S. Food and Drug Administration (FDA)-approved agents for the prevention of non-melanoma skin cancers, although sunscreens are widely recommended for this purpose, Elmets said. "However, even sunscreens are only modestly effective at preventing non-melanoma skin cancers. The demonstration that celecoxib can prevent these common malignancies heralds an entirely new approach for the prevention of these common malignancies," he said.
For the study, Elmets and colleagues randomly assigned 240 people with precancerous skin lesions called actinic keratoses to treatment with Celebrex or placebo. The researchers looked at the number of new lesions after three, six and nine months of treatment, and again two months after treatment had stopped.
The investigators found that the number of new precancerous lesions in both groups was the same.
However, by the end of the study, patients taking Celebrex had a 59 percent lower risk for non-melanoma skin cancers, compared with patients receiving placebo.
However, the study was stopped early after the FDA found that people in another trial that involved a similar drug had an increased risk for heart attacks. There were no such problems in this trial, the researchers noted, perhaps because the trial lasted only nine months.
In an editorial, Drs. Frank Meyskens Jr. and Christine McLaren, both of the University of California, Irvine, said that the finding that Celebrex helped reduce cancers but not precancerous lesions suggests that different mechanisms may be at work during different stages of tumor development.
Celebrex is one of a class of drugs called COX-2 inhibitors, which also include Bextra (valdecoxib) and Vioxx (rofecoxib). Vioxx was withdrawn from the market in 2004 and Bextra in 2005 because studies had suggested users faced heightened risks for heart attack. Celebrex did not show such a level of heightened risk and has remained on the market.
Commenting on the new study, Day said that even though she would not recommend that people take Celebrex for the sole aim of preventing skin cancer, it could prove an additional benefit for people who are already taking the drug to battle their arthritis pain.
"But for me it wouldn't be a first-line drug for people who have non-melanoma skin cancers, because of the other options and the cardiac risks," she said.
In the future this drug may be useful, at a lower dose, for preventing these cancers while avoiding the cardiac risk, Day added, but "I don't think this is ready for recommendation as a preventive for non-melanoma skin cancers."
For more information on skin cancer, visit the U.S. National Library of Medicine.
SOURCES: Craig A. Elmets, M.D., professor, dermatology, University of Alabama at Birmingham; Doris Day, M.D., dermatologist, Lenox Hill Hospital, New York City; Nov. 29, 2010, Journal of the National Cancer Institute, online
All rights reserved