Melanoma is the most deadly of all skin cancers and about 5 to 10 percent may be hereditary. As with most cancers, screening and early detection can make all the difference. Who, then, may benefit from genetic testing related to melanoma risk? In 2009, Huntsman Cancer Institute (HCI) led an international consortium of physicians and scientists to develop answers to this question. The result was the first set of worldwide guidelines.
“Of all melanomas that are hereditary in nature, up to 40 percent can be attributed to a mutation in the gene known as CDKN2A,” says Sancy Leachman, MD, PhD, HCI investigator, director of the Melanoma and Cutaneous Oncology Program, and author of the large, multicenter study. “Individuals with CDKN2A have a 76 percent lifetime risk for melanoma and up to a 17 percent risk for pancreatic cancer.”
|Sancy Leachman, MD, PhD|
Researchers already knew there are differences from country to country when considering a CDKN2A mutation. For example, in a country like England where the weather is frequently rainy and cloudy, melanoma is less common. Within a family history, fewer cases of melanoma would be needed to indicate the possibility of a CDKN2A mutation. In comparison, more cases would be needed within a family history in the United States, where the weather tends to be sunnier. But this study took the information a step further. “Our research utilized worldwide data to develop guidelines for genetic counseling and testing based on several factors, including a person’s country of origin,” says Leachman. Other factors include the following:
- How many family members have had melanoma?
- Has a person had more than one melanoma?
- Has a family member had pancreatic cancer?
Analyzing data from patients harboring CDKN2A, the research took two years to complete and involved the cooperation of physicians and scientists throughout the world. The data is significant because it led researchers to the conclusion that certain people are good candidates for genetic counseling and outlined guidelines for the first time. “Genetic counseling is now commonly used to identify individuals with hereditary colorectal, breast, and ovarian cancer,” says Leachman. “But genetic counseling for a CDKN2A mutation is not part of routine practice, despite the fact that commercial tests are available. We maintain that clinicians can help identify individuals at the highest risk for melanoma by referring appropriate candidates to a genetic counseling specialist,” she says.
According to Leachman, there are many variables surrounding this gene mutation and the guidelines can help. “Our study provides a framework that clinicians can use to identify candidates for genetic evaluation based on where they live and their clinical features,” Leachman says. “Identifying the risk may help prevent melanomas from occurring through improved screening and improve outcome of melanoma through earlier detection.”