Oral cancer affects around 4,600 people in the UK per year and the disease is more common in Scotland. It is a highly lethal disease and five year survival is around 50 per cent. At least three people die of or with oral cancer every day in the UK.
Saman Warnakulasuriya, Professor of Oral Medicine & Experimental Pathology at King’s, and lead researcher in the project says: ‘We are very excited by this discovery. Alcohol is a major risk factor for oral cancer. We have so far not been able to explain exact mechanisms how alcohol causes cancer of the mouth'.
Through study of a group of alcohol misusers the researchers have found that a break down product of alcohol – acetaldehyde can be detected in oral mucosal cells, and thereby provide a marker for alcohol metabolism.
The research team at King’s worked in collaboration with Professor Onni Niemela and Professor Seppo Parkkila at the University of Tampere, Finland. Dr Onni Niemela, a Professor of Laboratory Medicine at the University of Tampere, comments: ‘This product (acetaldehyde) identifies cells that are damaged by the alcohol, and through the study of these cells we can see how the damage may trigger diseases such as cancer in alcohol misusers’.
During alcohol ingestion acetaldehyde appears to react with proteins in the mouth to form rigid bonds with amino acids, otherwise known as adducts. This reaction interferes with both protein structure and function irreversibly. As a result the immune system recognises these adducts/bonds as foreign and fires off an inflammatory response.
In such cases, Acetaldehyde may also bind to DNA and blocks DNA repair machinery thereby triggering mutations and instigating cancers. A further combination of both tobacco and alcohol increase the dangers of acetaldehyde, and thereby the risk of cancer. ‘These new findings have illuminated a potential screening tool to detect who may have alcohol induced damage in their oral mucosal cells.
Victor R Preedy, Professor of Nutritional Biochemistry at King’s who contributed to this research, says: ‘The discovery of acetaldehyde adducts in tissues is very important and helps us understand how diseases may be caused. In this case the information adds to our understanding of mouth cancer. Acetaldehyde is a very small molecule and occurs naturally but in some circumstances it can be very damaging. We need to know much more about acetaldehyde’.
Dr Toru Nagao, Chief Maxillofacial Surgeon at Okazaki City Hospital in Japan who contributed tissue samples from a Japanese population for comparison with British subjects was keen to highlight the significance of the study to Japanese researchers and says: ‘There are genetic differences in Japanese populations that affect metabolism of alcohol, and few who cannot further breakdown acetaldehyde due to missing enzymatic mechanisms. Finding acetaldehyde in oral tissues may in the future be a marker for such aberrative pathways of alcohol metabolism'.
Source: By King's College London