Skin cancer is the abnormal growth of skin cells. It's a common cancer that can form on any part of the body, but it often occurs on sun-exposed skin.
The sun's ultraviolet (UV) rays can damage the DNA in your skin cells over time, resulting in the growth of cancerous cells.
Anyone can get skin cancer, but some things can increase a person's risk. Risk factors include having:
Skin cancer survival rates vary depending on the type of cancer. Some types of skin cancer are life-threatening when not treated early, while others have a low death rate.
The four most common types of skin cancer include:
Melanoma is skin cancer that forms in melanocytes. These are the skin cells that produce melanin, a pigment responsible for skin color.
Melanoma is the most dangerous type of skin cancer, but it's also a less common type.
Melanoma skin cancer usually presents as a brown or black spot that's larger than a mole.
The spot or bump can have an irregular border and shades of different colors. The bump might be reddish in color with black, blue, or purple spots mixed in.
Melanoma can develop anywhere on the body, such as the:
Basal cell carcinoma is the most common type of skin cancer. It accounts for more than 80 percent of skin cancer diagnoses.
It forms in the basal cells and is found on parts of the body heavily exposed to the sun. Although basal cell carcinoma grows slowly and doesn't usually spread to surrounding areas, it can be life-threatening if left untreated.
Symptoms of basal cell carcinoma include:
Squamous cell carcinoma also has a low death rate. It's slow-growing and can develop on the:
Symptoms include:
Merkel cell carcinoma starts in the Merkel cells. These are located below the top layer of skin near the nerve endings.
It's an aggressive type of skin cancer that's difficult to treat, but it's rare. It's more likely to occur in people older than 50 and those with a weaker immune system.
Merkel cell carcinoma is fatal if it spreads to the brain, lungs, liver, or bones.
An early sign of Merkel cell carcinoma is a fast-growing flesh-colored bump or nodule that may bleed. Nodules can also be red, blue, or purple.
If you receive a skin cancer diagnosis, the next step is to identify its stage.
Staging is how doctors determine whether the cancer has spread to other parts of your body. Staging is common with melanoma and Merkel cell carcinoma, because these cancers are more likely to spread.
Typically, basal cell and squamous cell carcinomas don't involve staging. These skin cancers are easily treated and don't usually spread. However, your doctor may recommend staging for larger lesions.
Staging is based on the size of the growth and whether it has high-risk features. High-risk features include:
Here's a general breakdown of skin cancer stages:
The outlook, or survival rate, for skin cancer depends on the type of skin cancer and stage of cancer at diagnosis.
Typically, the earlier you receive a diagnosis with skin cancer, the better your outcome. Cancer is harder to treat once it spreads to other parts of the body.
Melanoma is a deadly cancer when it spreads, but it's curable in its early stages.
The five-year survival rate for melanoma stages 0, 1, and 2 is 98.4 percent, according to the Melanoma Research Alliance.
The five-year survival rate of stage 3 melanoma is 63.6 percent. It's 22.5 percent for stage 4 melanoma.
According to the American Cancer Society, the five-year survival rate for Merkel cell stages 0, 1, and 2 is 78 percent. It's 51 percent for stage 3 and 17 percent for stage 4.
Because basal cell and squamous cell carcinomas are lower-risk skin cancers, there's little information on survival rates based on stage.
Both types of cancer have a very high cure rate. According to the Canadian Cancer Society, the five-year survival rate for basal cell carcinoma is 100 percent. The five-year survival rate for squamous cell carcinoma is 95 percent.
Skin cancer is a very preventable cancer. Here's how to protect yourself when outdoors:
Once a skin biopsy confirms skin cancer, your doctor will recommend a treatment based on the stage of the cancer.
To improve your outlook, it's important that you complete your treatment and schedule follow-up appointments as needed. Your doctor may want to see you every few months to make sure the cancer hasn't returned.
Also schedule annual skin exams with a dermatologist. Get into the habit of checking your own skin for abnormal growths, too. This includes your back, scalp, soles of feet, and ears.
You can also ask your doctor about local support groups for those with skin cancer, or search for support programs in your area.
Depending on the type, skin cancer can grow rapidly and become life-threatening if not treated early.
Talk to your doctor if you have any new growths on your skin or notice changes to an existing mole, bump, or birthmark.
Skin cancer has a high cure rate, but only if caught early.