What is skin cancer?
Skin cancer is the most prevalent form of all cancers in the United States and is identified when the cells that make up our skin begin to grow and rapidly divide in a disorganized manner. There are 3 main types of skin cancer:
- Basal cell carcinoma
- Squamous cell carcinoma
Basal cell carcinoma and squamous cell carcinoma are the most common types of skin cancer and may also sometimes be referred to as "non-melanoma skin cancer."
Melanoma is not as common as basal cell or squamous cell carcinomas, but is the most dangerous form of skin cancer. If left untreated or caught in a late stage, melanomas are more likely to spread to organs beyond the skin, making it difficult to treat and increasing the chances of death from skin cancer.
Fortunately, if skin cancer is identified and treated early, most are cured. This is why it is important to take a few safeguards and to talk with your healthcare provider if you think you are showing any signs of skin cancer.
Who is most at risk for skin cancer?
Although anyone can develop skin cancer, those that are most at risk for skin cancer are people who:
- Have had an organ transplant
- Tan or use tanning beds
- Get easily sunburned
- Have fair or freckled skin
- Have a family history of skin cancer
- Have blue eyes
- Take medications that suppress/weaken the immune system
People who work or spend more time outdoors have an increased risk for skin cancer, especially those in sunny climates. People with darker skin are still able to get skin cancer, but the risk is substantially lower. Organ transplant patients are up to 100 times more likely to develop squamous cell carcinoma skin cancer when compared to the general population, largely because they take medications that suppress their immune systems.
Risk factors unique to melanoma include a history of severe sunburns and an abundance of large and irregular moles.
Symptoms and Causes
What causes skin cancer?
The main cause of skin cancer is overexposure to sunlight, especially when it results in sunburn and blistering. Ultraviolet (UV) rays from the sun can damage the skin and, over time, lead to skin cancer. The UV light damages DNA in the skin and causes it to grow abnormally. Exposure to certain chemicals such as tar and coal can cause skin cancer for those with jobs that require them to frequently be in contact with these chemicals. Those with a weakened immune system also have an increased risk for skin cancer.
What are the signs of skin cancer?
Skin cancer can be a portion or spot of skin that does not heal. If you scrape your knee, it will usually heal within a month. Skin cancer will not heal.
The most common warning sign of skin cancer is a change on the skin, typically a new growth, or a change in an existing growth or mole.
- Basal cell carcinoma might appear as a small, smooth, pearly or waxy bump on the face, ears, and neck; or as a flat, pink/red- or brown-colored lesion on the trunk or arms and legs.
- Squamous cell carcinoma can appear as a firm, red nodule, or as a rough, scaly flat lesion that might itch, bleed, and become crusty. Both basal cell and squamous cell cancers mainly occur on areas of the skin frequently exposed to the sun, but can occur anywhere.
- Melanoma usually appears as a brown-pigmented patch or bump. It might resemble a normal mole, but usually has a more irregular appearance. 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 mm)
- Evolution: enlarging, changing in shape, color, or size. (This is the most important sign.)
Be alert to pre-cancerous skin lesions that can develop into non-melanoma skin cancer. They appear as small scaly, tan or red spots, and are most often found on surfaces of the skin chronically exposed to the sun, such as the face and backs of the hands.
If you have a mole or other skin lesion that is causing you concern, show it to your healthcare provider. He or she will check your skin and may ask you to see a dermatologist to have the lesion further evaluated. If needed to help with the diagnosis, the doctor can take a biopsy (remove a small sample) and send it to a laboratory to be examined under a microscope. The doctor will be able to call you with the results in about a week.
Diagnosis and Tests
How is skin cancer diagnosed?
Skin cancer is diagnosed by performing a biopsy. This is the removal of a sample of tissue that is then processed in a laboratory for detailed examination under a microscope by a pathologist. Sometimes a biopsy alone can remove all the cancer tissue and no further treatment is needed.
Management and Treatment
How is skin cancer treated?
Treatment depends upon the stage of the cancer. Some types of treatment include the following:
- Mohs micrographic surgery uses a scalpel to remove the tumor and thin layer of surrounding tissue.
- Excisional surgery involves a surgeon removing the tumor and some predetermined amount of surrounding healthy skin to be sure all cancer has been removed.
- Electrosurgery uses heat to burn the tumor and some surrounding area.
- Cryosurgery involves freezing the tumor and may require multiple treatments.
- Topical chemotherapy/immunotherapy is sometimes used to treat certain skin cancers or precancerous lesions.
- Radiation therapy
- Additional medical therapy or radiation therapy may be recommended if the cancer has a high risk of coming back in the same place or spreading beyond the skin to internal organs. If the cancer spreads beyond the skin to other organs or surrounding tissue, chemotherapy, targeted drug therapy, or immune therapy is often used.
Radiation therapy or topical therapy can be used for cancers in places that are hard to reach with surgery or for patients who are not able to have surgery.
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. Ultraviolet (UV) rays from the sun damage the skin, and over time lead to skin cancer.
Here are ways to protect yourself from skin cancer:
- Seek shade. Don't spend long periods of time (more than an hour) in direct sunlight.
- Wear hats with wide brims to protect your face and ears.
- Wear long-sleeved shirts and pants to protect your arms and legs.
- Use broad-spectrum sunscreens with an SPF (skin protection factor) of 30 or higher that protect against burning and tanning rays. Apply the sunscreen 30 minutes before you go outside. (Broad-spectrum sunscreens protect against both UV-B and UV-A rays.)
- Wear sunglasses to protect your eyes.
- Use a lip balm with sunscreen.
- Avoid the sun between 10:00 a.m. and 4:00 p.m.
- Show any changing mole to your healthcare provider.
Outlook / Prognosis
What is the outlook for people with skin cancer?
Nearly all skin cancers can be cured if they are treated before they have a chance to spread. The earlier skin cancer is found and removed, the better your chances for a full recovery. Ninety percent of those with basal cell skin cancer are cured. It is important to continue following up with a doctor to make sure the cancer does not return. If something seems wrong, call a doctor right away.