Gene variants increase risk of both skin cancer and obesity

Scientists have found a link between skin cancer and the FTO gene, which was already associated with obesity. Variants in the DNA sequence of FTO were associated with an increased risk of malignant melanoma, the deadliest form of skin cancer. Melanoma is the fifth most common cancer in the UK with about 12,800 new cases and about 2,200 deaths each year.

It is the first time that researchers have found variants of FTO associated with health problems unrelated to being overweight. Sometimes called the 'fat gene', people carrying a common variant are more likely to be overweight or obese, and FTO has also therefore been associated with weight-related health issues including diabetes.

The study looked at data from 13,000 malignant melanoma patients and 60,000 healthy individuals. The results suggest that FTO plays a more complex role in the body than previously thought.

'When scientists have tried to understand how the FTO gene behaves, so far they've only examined its role in metabolism and appetite', said Dr Mark Iles, a senior research fellow at the Leeds Institute of Molecular Medicine and leader of the study. He added that the link to melanoma 'raises the question whether future research will reveal that the gene has a role in even more diseases. It's now clear we don't know enough about what this intriguing gene does'.

Dr Julie Sharp, senior science information manager at Cancer Research UK, suggested that, if confirmed the findings might 'provide new targets for the development of drugs to treat melanoma. Advances in understanding more about the molecules driving skin cancer have already enabled us to develop important new skin cancer drugs that will make a real difference for patients'.

Other gene variants have previously been linked to melanoma and susceptibility to the condition can run in the family. However, the most common cause of malignant melanoma is still considered to be exposure to ultraviolet radiation from sunlight. Use of sunbeds is also considered a risk factor.

Dr Sharp confirmed that the best way to avoid melanoma was to avoid sunbeds and over-exposure to sunlight. 'Getting a painful sunburn just once every two years can triple the risk of melanoma', she said.