Skin Cancer

The skin protects against heat, sunlight, injury, and infection. Skin also helps control body temperature and stores water and fat. Skin is the most common type of cancer. It usually forms in skin that has been exposed to sunlight, but can occur anywhere on the body.

Skin has several layers  begins in the epidermis (outer layer), which is made up of squamous cells, basal cells, and melanocytes.

There are several different types of skin cancer. Squamous cell and basal cell skin cancers are sometimes called non-melanoma skin cancers. Non-melanoma skin cancer usually responds to and rarely spreads to other parts of the body. Melanoma is moreaggressive than most other types of skin cancer. If it isn’t diagnosed early, it is likely to invade nearby tissues and spread to other parts of the body. The number of cases of melanoma is increasing each year. Only 2 percent of all skin cancers are melanoma, but it causes most deaths from skin cancer.

Rare types of skin cancer include Merkel cell carcinoma, skin lymphoma, and Kaposi sarcoma.

Anatomy of the skin, showing the epidermis, dermis, and subcutaneous tissue.

Symptoms

You may not have any symptoms in the early stages of melanoma. Or a melanoma may be sore, or it may itch or bleed.

Most melanomas start as a new skin growth on unmarked skin. The growth may change color, shape, or size. These types of changes are an early sign that the growth is melanoma. But melanoma can also develop in an existing mole or other mark on the skin. Or it may look like a bruise that isn't healing or show up as a brown or black streak under a fingernail or toenail.

Skin cancer is the most common form of cancer in the United States. The two most common types are basal cell cancer and squamous cell cancer. They usually form on the head, face, neck, hands, and arms. Another type of skin cancer, melanoma, is more dangerous but less common.

Anyone can get skin cancer, but it is more common in people who

• Spend a lot of time in the sun or have been sunburned
• Have light-colored skin, hair and eyes
• Have a family member with skin cancer
• Are over age 50

You should have your doctor check any suspicious skin markings and any changes in the way your skin looks. Treatment is more likely to work well when cancer is found early. If not treated, some types of skin cancer cells can spread to other tissues and organs. Treatments include surgery, radiation therapy, chemotherapy, photodynamic therapy (PDT), and biologic therapy. PDT uses a drug and a type of laser light to kill cancer cells. Biologic therapy boosts your body's own ability to fight cancer.