Arthritis Drugs Studied to Prevent Oral Cancer

[editor"s note: The work by the researcher responsible for the study detailed in this story has been called into question - read the January 15, 2006 story on cancerpage here.]

By Paula Moyer

FRANKFURT Nov 21, 2002(Reuters Health) - A class of drugs often used to treat arthritis and other inflammatory conditions may be able to protect against oral cancer, according to Norwegian researchers.

Dr. Jon Sudbo and colleagues found that people with cancers and precancerous abnormalities in the mouth are more likely to have elevated levels of the enzyme cyclo-oxygenase 2 (COX-2).

Based on this, they looked to see if COX-2 inhibitors, or coxibs, can prevent these tumours from developing. Celecoxib (Celebrex) and rofecoxib (Vioxx) are examples of commonly used coxibs.

Sudbo, from the oncology department at the Norwegian Radium Hospital in Oslo, presented the investigative team"s findings here at the joint meeting of the American Association for Cancer Research, the National Cancer Institute and the European Organisation for the Research and Treatment of Cancer.

Sudbo and colleagues recruited 81 patients including 30 with normal oral mucous membranes, 22 with premalignant tissue and 29 with oral cancer. They wanted to determine whether COX-2 levels were associated with an abnormal number of chromosomes in the tissue"s DNA. A change in the number of chromosomes is a risk factor for cancer, Sudbo noted.

They found that COX-2 was more likely to be highly concentrated in patients with both premalignant tissue and cancer, in comparison to those with normal tissue. Among those with cancer, 26 (89.6%) had elevated COX-2 levels and 25 (86.2%) had abnormal numbers of chromosomes.

In the patients with premalignant lesions, COX-2 overexpression was found only in the nine patients with an aberrant number of chromosomes. The investigators followed seven of these patients for 5 years, in which time six (85.7%) developed oral cancer.

On the basis of these findings, Sudbo and his colleagues plan to see if treatment with a COX-2 inhibitor can prevent premalignant lesions from becoming cancerous.

Because 5 to 10 years can elapse between the identification of a premalignant oral lesion and progression to cancer, there is time to determine whether prevention is possible, he said. He and his colleagues chose to follow oral lesions because they are readily detectable, and investigators can follow them without using sophisticated equipment or subjecting patients to invasive procedures.

The ability to ward off such tumours would be a significant development, he said. Because oral cancers are typically aggressive, prevention would be a much more attractive treatment option than the "wait and see" approach that is typically practiced, he said.

The team plans to recruit 350 high-risk patients to a 5-year trial of the COX-2 inhibitor celecoxib, and to follow the patients for a total of 10 years. The primary risk factors for oral cancer are the use of tobacco and excessive consumption of alcohol, and 90% of oral cancer patients either smoke or use chewing tobacco.

"We"re still waiting for the data to determine whether COX-2 inhibitors can prevent premalignant lesions in the mouth from progressing," Sudbo told Reuters Health. He urged people at risk for such cancers to wait along with the investigators to see what, if any, protective effect these medications have.

"I would not recommend that people who smoke, the primary risk group, to treat themselves with COX-2 inhibitors with the anticipation that they will prevent oral cancers," he said.


"Reuters content is the intellectual property of Reuters Limited. Any copying, republication or redistribution of Reuters content, including by caching, framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in content, or for any actions taken in reliance thereon."