Why people with the greatest number of moles are at increased risk of the most dangerous form of skin cancer, this puzzle is solved by UK researchers. Their findings are published in the journal Nature Genetics.
The new study was led by Professors Julia Newton Bishop and Tim Bishop of the Melanoma Genetics Consortium (GenoMEL) at the University of Leeds.
Researchers looked at more than 10,000 people, comparing those who have been diagnosed with melanoma to those who do not have the disease.
Researchers across Europe and in Australia, looked at 300,000 variations in their research subjects’ genetic make-up, to pinpoint which genes were most significant in developing melanoma ? a disease which causes the overwhelming majority of skin cancer related deaths.
Across the large sample, a number of clear genetic patterns emerged.
It is already well known that red-haired people, those with fair skin and those who sunburn easily are most at risk of melanoma, and the people who had been diagnosed with melanoma were found to be much more likely to be carrying the genes most closely associated with red hair and freckles. “This is what we expected to find,” said Professor Bishop of the Leeds Institute of Molecular Medicine and the Cancer Research UK Centre at Leeds. “But the links seemed to be much stronger than we anticipated.”
“We had known for some time that people with many moles are at increased risk of melanoma. In this study we found a clear link between some genes on chromosomes 9 and 22 and increased risk of melanoma. These genes were not associated with skin colour,” he added.
“Instead, in joint research with colleagues at King’s College London and in Brisbane who counted the number of moles on volunteer twins, we showed that these genes actually influenced the number of moles a person has.”
The research shows that there are at least five genes which influence the risk of melanoma. A person carrying all the variants associated with an increased risk is around eight times more likely to develop melanoma than those carrying none, though the majority of people carry at least one of these variants.
Source: University of Leeds, UK