Blistering sunburns, fair skin and a family history of skin cancer are known risk factors for developing melanoma, the deadliest form of skin cancer. A new study led by a University of North Carolina Lineberger Comprehensive Cancer Center researcher confirms that certain inherited genetic features are also linked to a person’s melanoma risk.
In a paper published in The Journal of Investigative Dermatology, UNC Lineberger’s Nancy Thomas, MD, PhD, the Irene & Robert Alan Briggaman Distinguished Professor and Chair in the UNC School of Medicine Department of Dermatology, and her colleagues reported they verified that certain rare, naturally occurring genetic differences, or “polymorphisms,” on chromosome arm 10q are linked to an increased risk for melanoma.
Together with other known genetic features associated with a higher risk for this skin cancer – such as naturally occurring variants in a gene linked to red hair – researchers said these genetic differences could help inform who is at for this disease based on the DNA they inherit from their parents.
“In this study, we confirmed that these single nucleotide polymorphisms on a specific chromosome are associated with increased risk of melanoma,” Thomas said. “When you do genetic testing for melanoma, it’s a way to help define people’s risk.”
Together with their colleagues from the international Genes, Environment and Melanoma Study, the UNC researchers confirmed that a set of genetic variants located on chromosome arm 10q were linked to higher risk for melanoma. The association between this genetic difference and increased melanoma risk was previously reported by another group. The variants are rare, so it was difficult to confirm the findings.
In the study, which was designed to detect associations of rare genetic variants with melanoma, they evaluated incidence of these genetic changes in patients with two or more melanomas compared to patients with a single melanoma. In this analysis, they found that the presence of certain genetic variants was linked to increased risk for secondary melanomas. This population-based study evaluated cases diagnosed between 1998 and 2003 in Australia, Canada, Italy and the United States.
“We found that people with these variants were more likely to get a secondary melanoma,” Thomas said.
Additional questions remain from their work, Thomas said, such as why the variation in genetic code at this location is linked to higher melanoma risk.
“It’s biologically interesting because it seems there is something there that’s not really known at this point,” Thomas said. “We believe there is a gene located there that’s associated, but nobody knows what that is.”
Though there is greater awareness about the importance of sun safety, the American Cancer Society reports the incidence rate of melanoma has been increasing in the United States the past 30 years. It estimates that more than 96,000 cases of melanoma will be diagnosed in the U.S. this year, and more than 7,200 people will die from the disease.
In addition to Thomas, other authors included UNC Lineberger’s David Ollila, MD, the James and Jesse Millis Distinguished Professor in the UNC School of Medicine, and Jonathan A. Miles, a student in the UNC School of Medicine, along with Irene Orlow, Peter A. Kanetsky, Li Luo, Anne E. Cust, Bruce K. Armstrong, Anne Kricker, Hoda Anton-Culver, Stephen B. Gruber, Richard P. Gallagher, Robert Zanetti, Stefano Rosso, Lidia Sacchetto, Terence Dwyer, David C. Gibbs, Klaus J. Busam, Vikram Mavinkurve, B. Begg, and Marianne Berwick.
The study was supported by the National Cancer Institute and the National Institute of Environmental Health Sciences. Individual researchers were supported by Cancer Development Fellowships from Australia’s National Health and Medical Research Council and Cancer Institute NSW.