Nicotine replacement therapies could cause mouth cancer
Scientists, funded by the Medical Research Council, suggest that tobacco-replacement therapies containing nicotine could have the potential to cause mouth cancer.
The research, published in the international online science journal PLoS ONE, shows that levels of nicotine found in lozenges and chewing gums could increase the risk of mouth cancer.
Nicotine is an addictive substance found in cigarettes but is also widely used in tobacco-replacement therapies to help people quit smoking. Unlike other cigarette components such as tar and carbon monoxide, it was not thought to cause cancer.
The study was co-funded by the Medical Research Council PhD studentship and the Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary University of London.
Lead author Dr Muy-Teck Teh, of the Institute of Dentistry, Barts and the London School of Medicine and Dentistry, Queen Mary University London, and his team investigated the influence of the gene FOXM1 on mouth cancer. FOXM1 was already known to be expressed in higher levels in many other types of cancer.
Dr Teh said: ‘Our study found that FOXM1 was enhanced during the early progressive stages of mouth cancer. This means if someone has increased levels of FOXM1 in their mouth, it could indicate the early stages of mouth cancer.’
While the researchers were studying the influence of FOXM1, they also investigated the effect different tobacco substances had on human mouth cells.
Dr Teh said: ‘We were surprised to find that nicotine increased the levels of FOXM1 in the cells. We used the same amount of nicotine found in tobacco replacement therapies such as chewing gums and the amount was enough to activate the gene.’
Mouth cancer affects nearly 5,000 people in the UK each year and there has been a 17% increase in cases during the last four years.
Mouth cancer is often diagnosed at a late stage when the chances of survival are lower. The majority of cases are caused by either smoking or chewing tobacco and drinking alcohol.
Dr Teh said: ‘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.’
Smoking cigarettes has many harmful effects, including an increased risk of lung cancer and other forms of cancer, heart disease, stroke and stomach ulcers. It is the greatest single cause of illness and premature death in the UK.
Dr Teh warned: ‘We’ve showed the FOXM1 gene is activated by nicotine in human mouth cells which raises the possibility that nicotine could potentially increase the risk of mouth cancer. We want to stress, however, that further research is needed to conclusively determine whether this is indeed the case. There is no doubt however about the harmful effects of smoking, so smokers should make every effort to quit.’