Researchers at the University of Queensland, Australia believe they have uncovered the specific gene variations affecting the number, and types, of moles on the body as well as their role in causing skin cancer.
Led by Dr. Rick Sturm, a UQ Diamantina Institute researcher and associate professor, the study shows how mole analysis can help dermatologists determine a patient’s risk of developing melanoma. Results were published online ahead of publication in the Journal of Investigative Dermatology (Aug. 15, 2019).
The study observed three key mole classes: reticular, globular and non-specific under a dermatoscope to assess their pattern and risk factors.
“The goal was to investigate the genetic underpinnings of different mole classes or ‘nevi types’ and understand how these affect melanoma risk,” Dr. Sturm said in a press release.
“We found people who had more non-specific mole patterns increased their melanoma risk by two per cent with every extra mole carried. As we age, we tend to increase the amount of non-specific moles on our body, and the risk of developing melanoma increases.”
According to Dr. Sturm, globular and reticular mole patterns were found to change over time. Globular patterns were shown to decrease as patients grew older and typically diminished between the ages of 50 and 60 years.
Reticular moles also decreased over time but were more likely to head down a more dangerous path and develop into the non-specific pattern.
A cohort of more than 1,200 people, half of them melanoma patients, were recruited into the nearly nine-year study. Their results were then overlaid with genetic testing, which found variations in four major genes.
“We found some major relationships between genes and the number of moles and patterns when looking at the DNA,” Dr. Sturm said. “Certain gene types influenced the number of different nevi types–for example, the IRF4 gene was found to strongly influence the number of globular nevi found on the body.”
Dr. Sturm believes the findings will help dermatologists to better understand mole patterns and provide more holistic care to patients who may be at risk of melanoma.
“For a long time, clinicians have been interested in how pigmented moles relate to melanoma and melanoma risk,” he said. “With the availability of dermatoscopes and imaging, these results provide a new layer of understanding to guide clinical practice.”