Skin cancer

These days, many of us know about the harmful effects of the sun’s rays — and as a result, we may do our best to try to protect our skin from harm. Things like sunscreen and sun-shading hats may be a part of your everyday life. However, did you know that your history with UV rays over time may also put you at risk for skin cancer? It may be a surprising fact to learn, but having 5 or more sunburns doubles your risk for melanoma.1 It may be even more surprising to learn that skin cancer is the most common type of cancer in the U.S. and worldwide.1

Skin cancer is the abnormal growth of cells in the epidermis (outermost skin layer). Unrepaired DNA damage triggers the abnormal growths (mutations), which may lead to skin cells quickly growing and forming cancer. So, when we’re out in the sun for long periods and it impacts our skin, we may actually be damaging our skin cell DNA. The truth is, too much sun exposure that may result in a "sun tan" is actually a sign of damage and isn't safe for your skin.2

What are the types of skin cancer?

Our skin is the body’s biggest organ. So, it’s no surprise that it has 3 different layers and many kinds of cells. To understand the types of skin cancer, it’s helpful to know how the different cells work, where they are and how they might develop cancer. Here are the 3 main types of cells and their respective cancer types.3,4

Types of cells

Types of related skin cancers 

Squamous cells

These cells live in the upper and outer part of your epidermis. They constantly shed as new cells form. If they grow out of control, cancer might develop, called squamous cell carcinoma.

Squamous cell carcinoma

This kind of skin cancer often shows up on areas of our body that have gotten a lot of vitamin D (think face, ears, neck, lips, back of hands) and perhaps not a lot of sun protection. Less often, they may show up in scars or other skin sores, and even in the genital area. Squamous cell carcinoma may often be entirely removed or treated in other ways. And, if caught early enough, treatment may prevent it from spreading.

Basal cells

These cells live in the lower part of the epidermis called the basal cell layer. Basal cells replace squamous cells when they shed off the skin’s surface. If they grow out of control, basal cell carcinoma might develop.

Basal cell carcinoma

This kind of skin cancer is the most common (about 8 out of 10 cases).5  It may pop up in the same highly-exposed areas as squamous cell carcinoma. This cancer usually grows more slowly and rarely may make its way to other parts of the body. However, if left untreated, it may spread to nearby tissue and bone. Plus, if the whole thing isn’t removed, the cancer might come back in the same spot.


These cells make the brown pigment that gives your skin its tan color after you’ve been out in the sun. This pigment, called melanin, is our body’s natural sunscreen that helps to protect the deep layers of skin from UV rays. You may have already guessed that this is where melanoma might form.


Melanoma is less common than some other types of skin cancer. It may show up on the body, like the face and neck. But, it may be more likely to grow on the chest and back for men and on the legs for women. Melanoma may be more dangerous because it’s more likely to spread if it’s not caught and treated early.4

Who should I see if I'm concerned about skin cancer?

If you spot something new or unusual that fits one or more of the signs listed above, visit your dermatologist. You might also see your primary care provider (the doctor or provider you might see for your yearly exam), but dermatologists are skin care experts. Plus, if your primary doctor looks at your lesion and gives you kudos for catching something suspicious, chances are you may be referred to a dermatologist anyway. No matter which provider you choose, be sure to bring a list of the questionable areas on your body and be prepared for some possible hands-on assessment.12