At Florida Dermatology and Skin Cancer Centers, we often hear this question from patients after a skin cancer diagnosis: “How did I get skin cancer when I am hardly ever in the sun?”
The answer is a bit more complex than simply saying, “You got too much sun.”
Ultraviolet (UV) exposure is one of the most important contributors to skin cancer, but it is only one piece of the puzzle. Skin cancer develops when abnormal cells begin growing and multiplying in ways the body can no longer properly control. How likely that is to happen depends on a combination of environmental exposures, genetics, the characteristics of your skin, your immune system and your history.
In other words, skin cancer risk is personal. Two people can have similar lifestyles and very different levels of susceptibility. Understanding why can help you take a more informed approach to prevention and skin cancer screening.
Your Skin Has Its Own Level of UV Sensitivity
One of the biggest differences between people is how their skin naturally responds to ultraviolet radiation.
People with fair skin, light-colored eyes, blonde or red hair, freckles, and skin that burns easily or tans poorly generally have a higher risk of developing skin cancer. These characteristics are associated with less natural protection against UV-related cellular damage.
That doesn’t mean someone with darker skin cannot develop skin cancer. People of every skin tone can develop skin cancer. However, the overall risk is generally lower in people with more melanin, while certain skin cancers can be diagnosed later in people with darker skin because they may not realize they are at risk. So, while skin tone can influence risk, it does not eliminate the need for sun protection or skin checks.
Your Sun Exposure History Is Not the Whole Story
Every time UV radiation reaches your skin, it can cause cellular and DNA damage. Your body has repair mechanisms that work to correct this damage, but those mechanisms are not perfect. Over years of exposure, some damaged cells can accumulate changes that contribute to skin cancer.
This is one reason dermatologists often talk about cumulative sun exposure rather than focusing on one particular day at the beach.
However, the pattern of exposure can matter, too. Different types of skin cancer have different relationships with UV exposure. Basal cell carcinoma and squamous cell carcinoma are strongly associated with accumulated UV damage, while melanoma risk is influenced by factors including UV exposure, certain types of moles and genetic susceptibility.
And remember you don’t have to be a lifelong sunbather to accumulate UV damage.
Driving, walking the dog, gardening, playing golf, sitting outside at lunch or spending weekends outdoors all add up over time. Even incidental exposure counts.
Genetics Can Make Some Skin More Vulnerable
If skin cancer runs in your family, you may have wondered whether you’re simply “inheriting” skin cancer.
Some people inherit genetic characteristics that make them more susceptible to skin cancer. Certain inherited genetic mutations and syndromes are associated with an increased risk of basal cell carcinoma, squamous cell carcinoma or melanoma. Family history can also be important, particularly when multiple close relatives have had melanoma or unusual moles.
But having a family history does not mean skin cancer is inevitable.
Think of genetics as one factor that can influence the starting point. Environmental exposures and other individual factors can then influence what happens over a person’s lifetime.
This is also why comparing your skin cancer history with a sibling, spouse or friend isn’t necessarily useful. You may share similar environments but not identical biology.
The Number and Type of Moles You Have Can Change Your Risk
When it comes to melanoma, the number and characteristics of your moles can be important.
Having a large number of moles, particularly 50 or more, can increase melanoma risk. Atypical or dysplastic moles can also indicate increased susceptibility. A personal or family history of melanoma is another important consideration.
This doesn’t mean every unusual-looking mole is cancerous. In fact, most moles are harmless.
Instead, the overall pattern of your skin can help a dermatologist determine how closely you should be monitored.
This is one reason routine skin examinations can be valuable. A dermatologist isn’t just looking for one suspicious spot. We are also looking at the bigger picture: your skin type, number of moles, previous sun damage, past skin cancers and other risk factors.
Your Immune System Plays a Role, Too
Your immune system does more than fight infections. It also helps identify and eliminate abnormal cells.
When the immune system is weakened or intentionally suppressed, the body’s ability to control abnormal cells can be affected. People who have received organ transplants and take immunosuppressive medications, for example, have a significantly higher risk of developing certain skin cancers, particularly squamous cell carcinoma.
This is one reason dermatologists may recommend particularly careful and regular skin monitoring for people who are immunosuppressed.
It also demonstrates why skin cancer isn’t simply a consequence of not wearing enough sunscreen. There are biological factors inside the body that can influence how effectively damaged or abnormal cells are controlled.
Having Skin Cancer Once Can Increase Your Future Risk
A previous skin cancer diagnosis is another important piece of the puzzle.
If you’ve already developed basal cell carcinoma or squamous cell carcinoma, your risk of developing another skin cancer is higher. A history of melanoma similarly increases the likelihood of developing another melanoma.
This doesn’t mean another cancer will definitely occur. It means your skin has demonstrated that it is capable of developing cancerous changes, so continued monitoring becomes especially important.
For someone with a history of skin cancer, regular dermatology appointments aren’t simply about checking whether the original cancer has returned. We are also watching for entirely new lesions.
So Why Does One Person Develop Skin Cancer While Another Doesn’t?
There usually isn’t one single explanation.
Imagine two people who have spent 30 years living in the same Florida community. They may have received similar amounts of sunlight, but one person may have fair, freckled skin that burns easily, a strong family history of melanoma and numerous atypical moles. The other may have darker, more UV-resistant skin, fewer moles and no significant family history.
Their environmental exposure may be similar, but their biological susceptibility is not.
One person’s immune system, genetics, age, history of sunburns, medications and previous skin cancers can all contribute to their individual risk.
That’s why we don’t recommend using someone else’s experience as a measure of your own risk.
“My husband never wears sunscreen, and he’s never had skin cancer” isn’t evidence that your skin is equally protected.
Likewise, developing skin cancer doesn’t mean you necessarily did something wrong.
You Can’t Change Your Genetics, but You Can Change Some Risk Factors
Not every risk factor is within your control. You can’t change your genes, your natural skin tone or your family history. But there are meaningful steps you can take.
Protect your skin from UV exposure by seeking shade, wearing protective clothing and using broad-spectrum sunscreen with an SPF of 30 or higher. Avoid indoor tanning, which exposes the skin to UV radiation associated with skin cancer.
It’s also important to pay attention to changes in your skin. A spot that is growing, changing, bleeding, repeatedly crusting or simply looks different from everything else deserves attention.
And perhaps most importantly, know your personal risk factors.
Your dermatologist can help you understand whether your skin type, family history, number of moles, previous sun exposure, medications or history of skin cancer place you at higher risk.
Skin Cancer Isn’t a One-Size-Fits-All Disease
We often think of skin cancer as something that happens after too much sun. While UV exposure is a major contributor, the reality is much more nuanced.
Skin cancer is the result of multiple factors interacting over time. Some people have skin that is naturally more vulnerable to UV damage. Some have genetic predispositions. Some have numerous or atypical moles. Some have weakened immune systems. Others have accumulated decades of sun exposure without realizing just how much exposure they’ve received.
And sometimes, skin cancer develops in someone who doesn’t appear to have any obvious risk factors at all.
That’s why everyone should take their skin seriously, regardless of skin tone, age or lifestyle.
Sun protection isn’t about being afraid of the sun. It’s about reducing preventable damage. Skin exams aren’t about assuming something is wrong. They’re about giving a trained professional the opportunity to identify something early, when treatment is often most effective.
If you have questions about your personal risk for skin cancer, talk with your dermatologist.
Understanding your individual risk can help you determine how frequently you should have your skin examined and what you can do to protect your skin from skin cancer.
About Us
FLDSCC’s team of providers are experts in diagnosing and treating skin cancers; skin conditions and diseases such as eczema, acne, rosacea, dry skin, rashes, and warts; and chronic skin diseases and infections, while simultaneously tackling aging skin, wound care, and a multitude of other skin, hair, and nail concerns.
Several FLDSCC providers are fellowship-trained in Mohs micrographic surgery, an effective state-of-the-art treatment for most types of skin cancers. Mohs surgery involves minimal discomfort and encourages the greatest preservation of healthy tissue, which means less risk of scarring and superior cosmetic results.
FLDSCC has many convenient locations throughout the state. For more information, visit www.fldscc.com, or call (855) FLD-SKIN.
