Using data from 23andMe, researchers at Stanford University School of Medicine have found new genetic variants associated with one of the most common forms of skin cancer, squamous cell carcinoma.
In a study published in Nature Communications researchers were able to single out entirely new variants associated with the cancer and they were also able to confirm some previously identified genetic associations. n finding these new associations, the study also uncovered previously unknown biological mechanisms that trigger this form of squamous cell carcinoma.
“Given the large-scale and novel findings of this study, we anticipate that it will be well-received by the scientific community,” said Kavita Sarin, M.D. and Ph.D., who is an assistant professor of dermatology at Stanford and a co-author the paper.
The study is also one of the first genome wide association studies ever done for cutaneous squamous cell cancer. In their work the researchers found 11 genetic variants associated with this form of cancer — four of those have never been seen before.
Squamous cell carcinoma is the second most common skin cancer after basal cell carcinoma. In the United States about 10 percent of those with European ancestry will have some form of squamous cell carcinoma in their lifetime. Men, people with lighter skin, or those living near the equator, are at higher risk for the disease.
The seven previously known associations are all considered low-to-moderate penetrance sequence variants and are in genes or gene regions related to skin pigmentation, red hair and facial pigmentation— MC1R, ASIP, TYR, SLC45A2, OCA2, IRF4 and BNC2. The variant that lies near the gene BNC2 has been implicated in skin cancer as well as freckling and age spots. The four newly identified variants are in genes or gene regions that influence not only pigmentation, but freckling, age-related pigmentation spots, and skin color. Taken together the 11 genetic associations identified in this study are estimated to explain over 18 percent of the familial relative risk for squamous cell carcinoma.
For this study researchers looked at data from about 300,000 individuals. More than 286,000 of those are 23andMe customers who consented to research. Among those individuals, 6,000 reported having had squamous cell carcinoma and another 280,000 individuals said they’d never had the disease and were used as controls. The researchers followed that initial work by conducting a genome-wide association study using data from about 12,000 people involved in Harvard’s Nurses’ Health Study and Health Professionals Follow-Up Study. This second stage of the study allowed the researchers to further confirm their findings.
This study was led by scientists at Stanford University’s School of Medicine’s Department of Dermatology, and it included contributions from scientists at 23andMe, Indiana University, and Harvard Medical School. The same group — working with researchers at Brown, and at Tianjin Medical University Cancer Hospital and Institute in China — is also working on research into another very common form of skin cancer, basal cell carcinoma.