Nicotine chewing gum, lozenges and inhalers designed to help people to give up smoking may have the potential to cause cancer, research has suggested.
A study led by Muy-Teck Teh, of Queen Mary, University of London, has found that the effects of a genetic mutation that is common in mouth cancer can be worsened by nicotine in the levels that are typically found in smoking cessation products.
The results raise the prospect that nicotine, the addictive chemical in tobacco, may be more carcinogenic than had previously been appreciated.
“Although we acknowledge the importance of encouraging people to quit smoking, our research suggests nicotine found in lozenges and chewing gums may increase the risk of mouth cancer,” Teh said. “Smoking is of course far more dangerous, and people who are using nicotine replacement to give up should continue to use it and consult their GPs if they are concerned. The important message is not to overuse it, and to follow advice on the packet.”
Most nicotine replacement products have labels advising people to cut down after three months of use and to stop completely after six months.
In the new research, published in the journal Public Library of Science One, Teh’s team has investigated the role of a gene called FOXM1 in mouth cancer.
A mutation that raises the activity of this gene is commonly found in many tumors, and is also present in pre-cancerous cells in the mouth, the scientists found. This raised expression can then be worsened by exposure to nicotine, according to Teh.
“If you already have a mouth lesion that is expressing high levels of FOXM1 and you expose it to nicotine, it may add to the risk of converting it into cancer,” he said. “Neither the raised FOXM1 nor nicotine is alone sufficient to trigger cancer, but together they may have an effect."