What is skin cancer?
Skin cancer is a disease that involves the growth of abnormal cells in your skin tissues. Normally, as skin cells grow old and die, new cells form to replace them. When this process doesn’t work as it should — like after exposure to ultraviolet (UV) light from the sun — cells grow more quickly. These cells may be noncancerous (benign), which don’t spread or cause harm. Or they may be cancerous.
Skin cancer can spread to nearby tissue or other areas in your body if it’s not caught early. Fortunately, if skin cancer is identified and treated in early stages, most are cured. So, it’s important to talk with your healthcare provider if you think you have any signs of skin cancer.
Types of skin cancer
There are three main types of skin cancer:
Basal cell carcinoma, which forms in your basal cells in the lower part of your epidermis (the outside layer of your skin).
Squamous cell carcinoma, which forms in your squamous cells in the outside layer of your skin.
Melanoma, which forms in cells called melanocytes. Melanocytes produce melanin, a brown pigment that gives your skin its color and protects against some of the sun’s damaging UV rays. This is the most serious type of skin cancer because it can spread to other areas of your body.
Other types of skin cancer include:
Kaposi sarcoma.
Merkel cell carcinoma.
Sebaceous gland carcinoma.
Dermatofibrosarcoma protuberans.
How common is skin cancer?
Skin cancer is the most common cancer diagnosed in the U.S. In fact, about 1 in 5 people develop skin cancer at some point in their life.
Symptoms and Causes
Three common types of skin cancer are basal cell carcinoma, squamous cell carcinoma and melanoma.
What are the signs and symptoms of skin cancer?
The most common warning sign of skin cancer is a change on your skin — typically a new growth or a change in an existing growth or mole. Skin cancer symptoms include:
A new mole. Or a mole that changes in size, shape or color, or that bleeds.
A pearly or waxy bump on your face, ears or neck.
A flat, pink/red- or brown-colored patch or bump.
Areas on your skin that look like scars.
Sores that look crusty, have a depression in the middle or bleed often.
A wound or sore that won’t heal, or that heals but comes back again.
A rough, scaly lesion that might itch, bleed and become crusty.
What does skin cancer look like?
Skin cancer looks different depending on what type of skin cancer you have. Thinking of the ABCDE rule tells you what signs to watch for:
Asymmetry: Irregular shape.
Border: Blurry or irregularly shaped edges.
Color: Mole with more than one color.
Diameter: Larger than a pencil eraser (6 millimeters).
Evolution: Enlarging, changing in shape, color or size. (This is the most important sign.)
If you’re worried about a mole or another skin lesion, make an appointment and show it to your healthcare provider. They’ll check your skin and may ask you to see a dermatologist and have the lesion further evaluated.
What causes the condition?
The main cause of skin cancer is overexposure to sunlight, especially when you have sunburn and blistering. UV rays from the sun damage DNA in your skin, causing abnormal cells to form. These abnormal cells rapidly divide in a disorganized way, forming a mass of cancer cells.
What are the risk factors for skin cancer?
Anyone can get skin cancer, regardless of race or sex. But some groups get it more than others. Before the age of 50, skin cancer is more common in women and people assigned female at birth (AFAB). After 50, though, it’s more common in men and people assigned male at birth (AMAB). And it’s about 30 times more common in non-Hispanic white people than non-Hispanic Black people or people of Asian/Pacific Islander descent. Unfortunately, skin cancer is often diagnosed in later stages for people with darker skin tones. This makes it more difficult to treat.
Although anyone can develop skin cancer, you’re at increased risk if you:
Spend a considerable amount of time working or playing in the sun.
Get easily sunburned or have a history of sunburns.
Live in a sunny or high-altitude climate.
Tan or use tanning beds.
Have light-colored eyes, blond or red hair and fair or freckled skin.
Have many moles or irregularly shaped moles.
Have actinic keratosis (precancerous skin growths that are rough, scaly, dark pink-to-brown patches).
Have a family history of skin cancer.
Have had an organ transplant.
Take medications that suppress or weaken your immune system.
Have been exposed to UV light therapy for treating skin conditions such as eczema or psoriasis.
Diagnosis and Tests
How is skin cancer diagnosed?
First, a dermatologist may ask you if you’ve noticed changes in any existing moles, freckles or other skin spots, or if you’ve noticed any new skin growths. Next, they’ll examine all of your skin, including your scalp, ears, palms of your hands, soles of your feet, between your toes, around your genitals and between your buttocks.
What tests will be done to diagnose skin cancer?
If your provider suspects skin cancer, they may perform a biopsy. In a biopsy, a sample of tissue is removed and sent to a laboratory where a pathologist examines it under a microscope. Your dermatologist will tell you if your skin lesion is skin cancer, what type you have and discuss treatment options.
What are skin cancer stages?
Cancer stages tell you how much cancer is in your body. The stages of skin cancer range from stage 0 to stage IV. In general, the higher the number, the more cancer has spread and the harder it is to treat. But the staging for melanoma is different from non-melanoma skin cancers that start in your basal or squamous cells.
Melanoma staging
Stage 0 (melanoma in situ): The melanoma is only in the top layer of your skin.
Stage I: The melanoma is low risk and there’s no evidence that it has spread. It’s generally curable with surgery.
Stage II: It has some features that indicate that it’s likely to come back (recur), but there’s no evidence of spread.
Stage III: The melanoma has spread to nearby lymph nodes or nearby skin.
Stage IV: The melanoma has spread to more distant lymph nodes or skin, or has spread to internal organs.
Non-melanoma staging
Stage 0: Cancer is only in the top layer of your skin.
Stage I (1): Cancer is in the top and middle layers of your skin.
Stage II (2): Cancer is in the top and middle layers of your skin and moves to target your nerves or deeper layers of skin.
Stage III (3): Cancer has spread beyond your skin to your lymph nodes.
Stage IIIV (4): Cancer has spread to other parts of your body and your organs like your liver, lungs or brain.
Management and Treatment
How is skin cancer treated?
Treatment depends on the stage of cancer. Sometimes, a biopsy alone can remove all the cancer tissue if it’s small and limited to the surface of your skin. Other common skin cancer treatments, used alone or in combination, include:
Cryotherapy: Your dermatologist uses liquid nitrogen to freeze skin cancer. The dead cells slough off after treatment.
Excisional surgery: Your dermatologist removes the tumor and some surrounding healthy skin to be sure all the cancer is gone.
Mohs surgery: Your dermatologist removes only diseased tissue, saving as much surrounding normal tissue as possible. Providers use this to treat basal cell and squamous cell cancers and, sometimes, other skin cancers that develop near sensitive or cosmetically important areas, like your eyelids, ears, lips, forehead, scalp, fingers or genital area.
Curettage and electrodesiccation: Your dermatologist uses an instrument with a sharp, looped edge to remove cancer cells as it scrapes across the tumor. Then, they use an electric needle to destroy any remaining cancer cells. Providers often use this to treat basal cell and squamous cell cancers and precancerous skin tumors.
Chemotherapy: Your dermatologist or oncologist uses medications to kill cancer cells. Anticancer medications can be applied directly on the skin (topical chemotherapy) if limited to your skin’s top layer or provided through pills or an IV if the cancer has spread to other parts of your body.
Immunotherapy: Your oncologist gives you medications to train your immune system to kill cancer cells.
Radiation therapy: Your radiation oncologist uses radiation (strong beams of energy) to kill cancer cells or keep them from growing and dividing.
Photodynamic therapy: Your dermatologist coats your skin with medication, which they activate with a blue or red fluorescent light. This therapy destroys precancerous cells while leaving normal cells alone.
Complications/side effects of the treatment
The side effects of skin cancer treatment depend on what treatments your healthcare provider think will work best for you. Chemotherapy for skin cancer can lead to nausea, vomiting, diarrhea and hair loss. Other side effects or complications of skin cancer treatment include:
Bleeding.
Pain and swelling.
Scars.
Nerve damage that results in loss of feeling.
Skin infection.
Regrowth of the tumor after it’s been removed.
Prevention
Can skin cancer be prevented?
In most cases, skin cancer can be prevented. The best way to protect yourself is to avoid too much sunlight and sunburns. UV rays from the sun damage your skin, and over time, this may lead to skin cancer.
How can I lower my risk?
Ways to protect yourself from skin cancer include:
Use a broad-spectrum sunscreen with a skin protection factor (SPF) of 30 or higher. Broad-spectrum sunscreens protect against both UV-B and UV-A rays. Apply the sunscreen 30 minutes before you go outside. Wear sunscreen every day, even on cloudy days and during the winter months.
Wear hats with wide brims to protect your face and ears.
Wear long-sleeved shirts and pants to protect your arms and legs. Look for clothing with an ultraviolet protection factor label for extra protection.
Wear sunglasses to protect your eyes. Look for glasses that block both UV-B and UV-A rays.
Use a lip balm with sunscreen.
Avoid the sun between 10 a.m. and 4 p.m.
Avoid tanning beds. If you want a tanned look, use a spray-on tanning product.
Ask your healthcare provider or pharmacist if any of the medications you take make your skin more sensitive to sunlight. Some medications known to make your skin more sensitive to the sun include tetracycline and fluoroquinolone antibiotics, tricyclic antibiotics, the antifungal agent griseofulvin and statin cholesterol-lowering drugs.
Regularly check all your skin for any changes in size, shape or color of skin growths or the development of new skin spots. Don’t forget to check your scalp, ears, the palms of your hands, soles of your feet, between your toes, your genital area and between your buttocks. Use mirrors and even take pictures to help identify changes in your skin over time. Make an appointment for a full-body skin exam with your dermatologist if you notice any changes in a mole or other skin spot.
Outlook / Prognosis
What is the outlook for people with skin cancer?
Nearly all skin cancers can be cured if they’re treated before they have a chance to spread.
The earlier skin cancer is found and removed, the better your chance for a full recovery. It’s important to continue following up with your dermatologist to make sure cancer doesn’t come back. If something seems wrong, call your doctor right away.
Most skin cancer deaths are from melanoma. If you’re diagnosed with melanoma:
The five-year survival rate is 99% if it’s detected before it spreads to your lymph nodes.
The five-year survival rate is 66% if it has spread to nearby lymph nodes.
The five-year survival rate is 27% if it has spread to distant lymph nodes and other organs.
When should I see my healthcare provider?
Make an appointment to see a healthcare provider or dermatologist as soon as you notice:
Any changes to your skin or changes in the size, shape or color of existing moles or other skin lesions.
The appearance of a new growth on your skin.
A sore that doesn’t heal.
Spots on your skin that are different from others.
Any spots that change, itch or bleed.
Your provider will check your skin, take a biopsy (if needed), make a diagnosis and discuss treatment. Also, see a dermatologist annually for a full skin review.
What questions should I ask my healthcare provider?
Questions to ask your dermatologist may include:
What type of skin cancer do I have?
What stage is my skin cancer?
What tests will I need?
What’s the best treatment for my skin cancer?
What are the side effects of that treatment?
What are the potential complications of this cancer and the treatment for it?
What outcome can I expect?
Do I have an increased risk of additional skin cancers?
How often should I be seen for follow-up checkups?
Additional Common Questions
How does skin cancer become a life-threatening cancer?
You may wonder how cancer on the surface of your skin becomes a life-threatening cancer. It seems logical to think you could just scrape off the skin with the cancer cells or even remove the cancerous skin lesion with a minor skin surgery and that’s all that would be needed. These techniques are successfully used if cancer is caught early.
But if skin cancer isn’t caught early, something that’s “just on my skin” can grow and spread beyond the immediate area. Cancer cells can break away and travel through your bloodstream or lymph system. They can settle in other areas of your body and begin to grow and develop into new tumors. This travel and spread is called metastasis.
The type of cancer cell where cancer first started — called primary cancer — determines the type of cancer. For example, if malignant melanoma metastasized to your lungs, the cancer would still be called malignant melanoma. This is how that superficial skin cancer can turn into life-threatening cancer.
Why does skin cancer occur in more non-sun-exposed body areas in people of color?
Scientists don’t fully know why people with darker skin tones develop cancer in non-sun-exposed areas like the palms of your hands and feet. They think that the sun is less of a factor, though. That said, dermatologists still see plenty of UV sunlight-induced melanomas and squamous cell skin cancer in people with skin tones ranging from fair to very dark.
Are all moles cancerous?
Most moles aren’t cancerous. Some moles are present at birth. Others develop up to about age 40. Most adults have between 10 and 40 moles.
In rare cases, a mole can turn into melanoma. If you have more than 50 moles, you have an increased chance of developing melanoma.
A note from Cleveland Clinic
Skin cancer can happen to anyone. What may seem like an innocent cosmetic imperfection may not be. Performing regular skin self-checks is important for everyone. But it’s especially important if you have an increased risk of skin cancer.
Your skin is the largest organ in your body. And it needs as much attention as any other health concern. Check your skin every month for any changes in skin spots or any new skin growths. Take steps to protect your skin from the sun. And don’t forget to schedule regular skin checks with your dermatologist.