Skin cancer is the most common form of cancer, but it’s also one of the most preventable.
Fortunately, knowing your risk along with protecting your skin from the sun can lower your chances of developing all three common forms. Early detection — often through self-exam and mole checks — can also go a long way toward ensuring healthy outcomes.
In the U.S. alone, an estimated 3.3 million people are diagnosed with basal cell or squamous cell cancers each year, according to the American Cancer Society. Melanoma makes up a small percentage of all skin cancers, but it is the most lethal, contributing to the vast majority of skin cancer-related deaths, according to statistics from the Centers for Disease Control and Prevention.
As part of 23andMe+, members can now access two reports on these three common forms of skin cancer. These include a Skin Cancer (Melanoma) report, and a Skin Cancer (Basal and Squamous Cell Carcinomas) report. Both are powered by 23andMe Research.
The new reports use machine learning techniques to estimate a person’s likelihood of developing one of these forms of skin cancer. In the report on Skin Cancer (Basal and Squamous Cell Carcinomas), we make the estimate by using a statistical model that includes more than 11,000 genetic variants into account. For the report on Skin Cancer (Melanoma), the statistical model includes more than 1,800 genetic variants. The reports also take into account a person’s ethnicity and birth sex.
Skin Cancer Risk and Ethnicity
Because these types of skin cancers are so rare among certain ethnicities, we cannot provide genetic results for everyone at this time. In the cases of people of East and Southeast and South Asian descent, the likelihood of developing one of these cancers is so small that statistical models predicting these likelihoods based on genetics do not meet our scientific standards.
These models include customers’ results for thousands of genetic markers and are available for people of European, Latino, Northern African, Central and Western Asian as well as Sub-Saharan African descent. So, in the report on basal and squamous cell carcinomas, we are unable to provide a genetic likelihood for people of East and Southeast Asian and South Asian descent. In addition, in the report on melanoma, we are unable to provide a genetic likelihood for people of East Asian, Southeast Asian, South Asian, and African descent.
While skin cancer can develop in people of all ethnicities, people of European descent have a much higher risk. The lifetime risk for melanoma is about two percent for people of European descent, but only about .1 percent among those of African descent. For people of Latino or Hispanic descent, it’s a little more than half a percent. But for people with darker skin, diagnosing melanoma often happens much later, resulting in potentially worse outcomes. In addition, people with darker skin are much more likely to develop melanoma in locations that get less sun, such as the palms of the hands, soles of the feet, beneath the fingernails, or even inside the mouth.
That’s what makes both prevention and skin self-exam so important. Experts recommend knowing the ABCDEs of melanoma and performing a skin self-exam about once a month. It’s important to keep an eye on your skin and talk to a healthcare professional like a dermatologist if you notice any changes, including new or changed moles, bumps, or sores.
A Little Bit More About Skin Cancer
Basal and squamous cell carcinomas usually develop on areas of the skin that are more exposed to the sun, like the face and hands. The first sign might be a bump, growth, or a sore that doesn’t heal. For people with darker skin, these types of cancers often appear more like a dark brown or black bump that might be glossy and have a rolled border. Both are typically very treatable, tend to grow slowly, and often remain in the first layers of skin.
Melanomas are different and much more serious. While they can appear in much the same way, or develop from an existing mole, what happens below the skin’s surface is what makes them so dangerous.
That’s because melanomas are more likely than other skin cancers to spread locally or metastasize to other parts of the body. Again, this is why early detection is so important so that they can be treated before cancer can spread.
In the case of skin cancer, we know that environmental factors, particularly sun exposure and repeated sunburns, increase the risk substantially. But research has found that genetic factors and specific traits also play a role.
23andMe has been involved in several research projects to create polygenic scores that would better estimate the likelihood of developing skin cancer. These statistical models incorporate not just genetic variants but also family cancer history, skin pigmentation, sun exposure and body mass index, for instance.
Not long ago, using data from consented 23andMe research participants, researchers from Indiana University found new genetic variants associated with squamous cell carcinomas. And a few years before, researchers at Stanford, also using 23andMe data, found new genetic variants associated with the risk of melanoma. Most recently, a team of researchers in Australia, with the help of 23andMe data, found more than 70 genetic variants associated with melanoma and identified correlations between melanoma and autoimmune diseases such as psoriasis and rheumatoid arthritis.
Being vigilant especially for new moles or discolored skin, and protecting your skin from the sun, all can help lower the likelihood of developing skin cancer.
Self-exam is a little tougher for areas like your back so having a partner, your doctor, or a dermatologist take a look is a good idea.
Everyone should be aware of the risk for skin cancer, but some individuals have more risk than others. Individuals with lighter-skin, or a lot of moles, or who sunburn easily, or who have a family history of skin cancer, should be particularly vigilant.
Sun protection is important, but it’s also a good idea to avoid tanning beds.
23andMe’s new skin cancer reports (powered by 23andMe research) are available to all annual subscribers to the 23andMe+ Membership. To learn more about your report, go here and here.
Not yet an annual subscriber to the 23andMe+ Membership?
Find out more here.