Skin cancer is the most common cancer in the United States, affecting more than two million people each year. According to the American Cancer Society, "melanoma accounted for about 68,130 cases of skin cancer in 2010."
Skin cancer is also very often preventable, and—with regular self-exams— can usually be detected and treated before it progresses.
Types of Skin Cancer
Cancer results when malignant tumors invade tissues in the body. Tumors form when the normal process of cell division goes awry. Instead of the cells dividing in a controlled manner, they divide uncontrollably creating a mass of tissue, known as a tumor. Like other forms of cancer, it is crucial to treat skin cancer right away to prevent cells from invading other tissues and organs.
The skin cancer types include:
- Basal cell carcinoma: the most common form; develops from abnormal cell growth in lowest layer of the epidermis
- Squamous cell carcinoma: develops in the middle layer of the epidermis
- Melanoma: the least common but the most dangerous type; it forms in the melanocytes (pigment-producing cells)
Melanoma vs. Nonmelanoma
Melanoma is the most serious type of skin cancer. It develops in cells called melanocytes, which are what gives our skin its color. Exposure to the sun causes melanocytes to make the skin tan. This may seem good if you crave that "healthy" glow, but tanned skin is the body's indicator that it has received too much ultraviolet (UV) light. Overexposure to UV rays can cause the melanocytes to begin to grow abnormally and eventually evolve into melanoma.
Nonmelanoma skin cancer includes basal cell and squamous cell carcinomas. These develop on parts of the skin that are most exposed, such as the face, neck, arms, and backs of the hands. Nonmelanoma skin cancers do not usually spread to other parts of the body and are cured if detected early.
Skin cancers are typically painless, but that makes them no less dangerous. Symptoms of skin cancer include:
- small, shiny, pale, or waxy lump
- firm red lump
- lump that bleeds
- flat red spot that is rough or scaly
Signs to look for include changes in your skin (like a new growth) or sores that have trouble healing. These may indicate skin cancer. Skin changes can occur in various parts of the body, including:
Learn more about the symptoms of skin cancer.
What Causes Skin Cancer?
Too much exposure to UV radiation from the sun can lead to skin cancer. Artificial radiation from sun lamps and tanning beds are equally dangerous.
While there are certain factors that can increase your risk, such as age and complexion, skin cancer can affect anyone. Fair-haired, light-skinned individuals are more at risk, but this does not exclude dark-haired, dark-eyed people from developing skin cancer.
Risk factors for skin cancer include:
- skin: fair skin (freckles or burns easily)
- hair color: red or blonde
- age: over 50
- gender: men are more likely to develop skin cancer than women
- over-exposure: too much sun, especially history of severe sunburn, poses higher risks
- genetics: some genetic diseases, or having a family history of melanoma
- weakened immune system: a weakened immune system makes an individual more vulnerable to developing nonmelanoma skin cancer
Learn more about the causes of skin cancer.
The best way to prevent skin cancer is to limit your time in the sun. When you do spend time outdoors, make sure to protect yourself. Cover arms and legs with pants and long-sleeved shirts, and protect your eyes with 99-100 percent UV absorption sunglasses.
Learn more about sun-protective clothing.
Apply sunscreen with a factor of SPF 15 or stronger to exposed areas, like your neck and face. Don't forget your head. Cover your head with a wide-brimmed hat to shield it from the sun's powerful rays. It's also recommended to avoid peak sun hours between 10am and 4pm.
Learn more about preventing skin cancer.
Skin Cancer Self-Exam
Whether you are at high risk or not, health experts recommend giving self-exams to check for signs of skin cancer. Check regularly and alert your dermatologist or primary care doctor if you see anything that looks suspicious.
What you'll need:
- good lighting
- a full-length mirror
Examine moles and birthmarks, watching for any of the following signs:
- unusual-looking lesions
- asymmetrical shapes
- color variation
- anything larger than a pencil eraser
- irregular or rough borders
- Remember to check your scalp and to check along the hairline.
- Don't be shy: if you're examining a hard-to-see area, ask a partner or friend to help.
Write what you see:
Record the size, location, and appearance of all moles and birthmarks on your body.
Next time, you can refer to these to see if there have been any changes.