What you should know about skin cancer
Skin cancer is the most common type of cancer in the United States. Below are some common questions and answers about the basics of the disease, its symptoms, prevention and risk factors.
What causes skin cancer?
As with many cancers, skin cancer develops when damaged cells grow uncontrollably. Most skin cell damage is caused by exposure to ultraviolet (UV) radiation from the sun or tanning beds. Cells may also be damaged by inherited DNA mutations or cell replication errors, or they may develop in patients whose immune system is suppressed, such as those who received an organ transplant or were infected with the HIV virus.
Is melanoma considered skin cancer?
Yes. Melanoma is a rare but very aggressive form of skin cancer. Melanoma accounts for about 2 percent of all skin cancers, but it is responsible for most skin cancer deaths. The disease develops in the melanocytes, or the cells that lie just below the skin surface and give skin its color. Like most skin cancers, exposure to UV radiation is a major cause of melanoma. But unlike most skin cancers, melanoma may develop on parts of the body not normally exposed to the sun, such as the groin, armpits or bottoms of the feet. Melanoma also is more prone to travel (metastasize) than most skin cancers. Melanoma cells most often travel to the lungs, liver, bone and brains. Surgeries required to remove melanoma from the skin are typically more invasive and involve wider and deeper incisions than procedures to remove other skin cancers, such as basal cell or squamous carcinomas. Removing nearby lymph nodes may also be necessary to determine whether the cancer has spread.
Learn more about melanoma
What are the other different types of skin cancer?
The primary types of skin cancer are:
- Basal cell carcinomas: This is the most common form of skin cancer, accounting for nearly 80 percent of all cases, according to the American Cancer Society. These cancers occur in the cells just below the skin's surface.
- Squamous cell carcinomas: This form of skin cancer accounts for about 20 percent of all cases. Squamous cells are also found in the throat, the lining of the digestive system and respiratory tract and major organs like the liver and kidneys.
- Merkel cell carcinomas: Though very rare, this cancer is an aggressive form of skin cancer. Merkel cells, sometimes called touch cells because they give the skin its ability to sense touch, are found below the epidermis, nestled next to nerve endings.
- Kaposi's sarcoma (KS): This type of skin cancer may appear as purplish blotches or lesions on the skin (usually on the face or legs), but it may also form inside the mouth or in lymph nodes. In rare cases, lesions may develop in the lungs, causing breathing problems.
- Lymphoma of the skin: Lymphoma, which is cancer of the lymphatic system, may form in a variety of locations in the body, including the spleen, lymph nodes, thymus and skin. This cancer may appear as red or purple patches, moles or pimples on the skin that may itch or ulcerate. Other symptoms may include fatigue and weight loss.
What are the signs and symptoms of skin cancer?
Skin cancer usually begins as a simple, painless spot, sore or rash on the skin. If that sore or rash doesn’t heal, or if the spot changes color or becomes irregular in shape, it may be skin cancer. Basal cell carcinomas on the head or neck may appear as a pale patch of skin or a waxy bump. On the chest, it may look more like a brownish scar or flesh-colored lesion. These spots may bleed or ooze and become crusty in some areas. Squamous cell carcinomas may also develop as a lump on the skin. But, unlike the smooth and pearly appearance of a basal cell carcinoma, these lumps may be rough on the surface. The cancer may also form a reddish, scaly patch. Merkel cell carcinoma may appear as a fast-growing, dome-shaped lump on the skin. These bumps are usually painless and may be red or purple. Melanoma may appear as a dark spot on the skin. It may change shape and color and bleed as it develops. It may be difficult to tell if a growth on the skin is a mole, a benign growth or skin cancer. That’s why experts recommend that suspicious or fast-growing spots be checked by a doctor.
How can I tell if my skin cancer is melanoma?
The ABCDE method may help you determine if an abnormal growth on your skin may be melanoma:
Asymmetry: The mole has an irregular shape.
Border: The edge is not smooth, but irregular or notched.
Color: The mole has uneven shading or dark spots.
Diameter: The spot is larger than the size of a pencil eraser.
Evolving or Elevation: The spot is changing in size, shape or texture.
The only way to be sure if a mole is melanoma is to have it examined by a doctor.
Learn more about melanoma risk factors