Understanding skin cancer
These days, many of us know about the harmful effects of the sun’s rays and we might try our best to protect our skin. However, our personal history with UV rays over time may put us at risk for skin cancer. In fact, having 5 or more sunburns doubles your risk for melanoma.1(That's right, just 5.) 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, there’s no such thing as a safe sun tan.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
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.
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
A skin biopsy is needed to diagnose any kind of skin cancer. Even if a spot looks really suspicious, the way to know for sure if it’s cancerous (and what kind) is to remove and analyze it. Your dermatologist can often easily remove the spot in question during your visit. It’s important to see your dermatologist right away if you notice something that looks suspicious. At the very least, if your dermatologist doesn’t think it’s concerning, you may have peace of mind.6
Spotting skin cancer can be tricky, but it may be fairly easy to find if you know the warning signs. Have you ever looked in the mirror and said, “When did that get there?” Innocent moles, freckles and age spots may pop up all the time. The key is learning what to look for, keeping track of any changes you see and getting to know your body so nothing new gets past you.
Here’s a list of how basal cell carcinoma, squamous cell carcinoma and melanoma might appear:7
Basal cell carcinoma:
- Pearly or waxy bump
- Flat, flesh-colored or brown scar-like lesion
- Bleeding or scabbing sore that keeps coming back
Squamous cell carcinoma:
- Firm, red nodule
- Flat lesion with a scaly, crusted surface
- Larger, brownish spot with darker speckles
- Painful lesion that itches or burns
- Dark lesion on palms, soles, fingertips, toes, mouth, nose, vagina or anus
Other possible signs of skin cancer include:6
- New, unusual or changing mole
- Dome-shaped growth
- Brown or black streak under your nail (you can get skin cancer under your nails — who knew?)
Skin cancer may show up differently on everyone so it’s important to pay attention to changes on your skin. Some of these spots may look small and innocent, but they may be more powerful (and sometimes more dangerous) than you might think.
The ABCDEs of melanoma is an acronym to help you remember and recognize signs of melanoma. Keep these in mind when you’re doing your self-checks.8
- Asymmetry: The spot is asymmetrical in size or shape. Think of a mole. Most are round or oval, right? Well, if the spot on your skin looks a lot different from that shape, it might be melanoma. In fact, most melanomas are asymmetrical.
- Border: Borders that are uneven, or have jagged edges.
- Color: As in multiple colors. If you notice a spot with a single shade of brown, you may be in good shape. Seeing different shades of brown, tan, black, red, white or blue? See your dermatologist stat.
- Diameter or dark: Check for a diameter about the size of a pencil eraser or bigger. That might be a warning sign. Also check to see if any spots on your body seem much darker than the rest.
- Evolving: Any changes in size, shape, color or elevation might be a red flag. Or, things like bleeding, itching or crusting.
If you notice anything listed above, pay your dermatologist a visit and bring a list of your findings.
Anyone can get skin cancer, but here’s a list of factors that may increase your risk:9
- Fair skin: Having less melanin in your skin may mean less natural protection from the sun’s UV rays.
- History of sunburns: Having one or more blistering (ouch) sunburns in your life may increase your risk.
- Personal or family history: If a parent or sibling has been diagnosed, or you’ve had it once already, your chances may go up for developing skin cancer (or possibly getting it again).
- Too much sun exposure: Spending a lot of time outside under the sun (even if you’re protected with sunscreen or clothing) may increase your risk. Of course, this may even include visits to tanning beds.
- Many moles: Having a lot of moles or moles that look bigger and irregular compared to the others (called dysplastic nevi) may increase your risk. Keep an eye on those irregular moles for noticeable changes that fit one of the ABCDEs.
- Precancerous skin lesions: These are called actinic keratoses and may increase your risk.
- Exposure to radiation or certain substances: Having radiation or being exposed to certain chemicals, like arsenic, might increase your chances for developing skin cancer.
Protecting your skin from too many UV rays may help reduce your risk of skin cancer. We’re talking about arms, legs, hands, ears, lips, face, eyes — the whole body. Here’s a list of simple lifestyle habits to help prevent skin cancer:9
- Avoid the sun when it’s strongest. In North America, the sun’s rays are the strongest UV between 10 AM and 4 PM. Try to plan outdoor activities outside that mid-day window. If you’ve got to be out when the sun is blazing, bring your eye, skin and lip protection.
- Wear sunscreen, all year long. Getting in the habit of applying sunscreen to your face as part of your daily skin routine will help protect your skin (even if you’re not spending much time outside). Planning to enjoy some rays? Be sure to apply sunscreen everywhere the sun touches and reapply at least every 2 hours.
- Step away from the tanning bed. Tanning beds might have been popular way back when, but it's important to know the UV rays in those lights are bad for your skin.
- Know which meds may make you more susceptible to the sun. Some medicines, including certain antibiotics, may make your skin more sensitive to the sun. If that’s the case, be cautious if you’re out and about.1
- Check your skin regularly. You may be your own best doctor when it comes to spotting something new. Check yourself from head to toe and everything in between for the signs we listed above. Keep a journal of your skin health so you can easily track changes.
- See a dermatologist once a year. If you’re at average risk for skin cancer, it’s a good idea to see a dermatologist once a year for a total head-to-toe check. And, be sure to prepare so you can get the most from your visit.11
Sometimes, that biopsy we mentioned above (where the doctor removes the whole lesion) might be all that’s needed to treat smaller cancers that are close to the skin’s surface. Other skin cancers, depending on size, shape, location and stage, may need additional treatment. Those options include:11
- Freezing: Some early cancers may be small enough to be frozen off with liquid nitrogen.
- Excisional surgery: This is a fancy name for surgery that’s used to remove the lesion and any surrounding skin to make sure the cancers cells have been caught.
- Mohs surgery: For certain hard-to-treat skin cancers, your doctor may remove the lesion layer by layer and checks out each one under a microscope. Once the cells look healthy, your doctor may know it’s time to wrap up. This is used on places (like the nose) where you may want to keep as much healthy surrounding skin intact as possible.
- Curettage and electrodesiccation: Sometimes used along with liquid nitrogen, this procedure involves a circular blade (called a curet) that scrapes away layers of cancer. Then, an electric needle may kill any remaining cancer cells. It’s a quick treatment that’s often used for basal cell and squamous cell carcinomas.
- Radiation: If the cancer can’t be totally removed during surgery, you may need radiation to kill the cancer cells.
- Chemotherapy: Creams and lotions that have cancer-fighting agents may be used directly on the skin to help treat cancers that are just on the top layer of skin. Chemo drugs may also be used to treat cancers that have spread.
- Photodynamic therapy: This uses a combination of lasers and medicine to help make the cancer sensitive to light, which may eventually destroy it.
- Immunotherapy: This approach works a little like a vaccine — but for skin cancer. It may help your body recognize and fight off cancer cells.
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
- Skin Cancer Facts & Statistics skincancer.org, 2021.
- The Risks of Tanning fda.gov, 2021.
- What Are Basal and Squamous Cell Skin Cancers? cancer.org, 2019.
- What Is Melanoma Skin Cancer? cancer.org, 2019.
- Key Statistics for Basal and Squamous Cell Skin Cancerscancer.org, 2021.
- How can I tell if I have skin cancer? aad.org, 2021.
- Skin cancer- Symptoms and causesmayoclinic.org, 2020.
- The ABCDEs of melanoma skincancer.org, 2021.
- Skin cancer- Symptoms and causesmayoclinic.org, 2020.
- The Sun and Your Medicinefda.gov, 2021.
- Skin cancer- Diagnosis and treatment mayoclinic.org, 2021.
- Annual Exams skincancer.org, 2021.