What is skin cancer?

Skin cancer is one of the most common types of cancer. It is a tumor, an uncontrolled growth of abnormal cells, on the skin. The skin appears to change in texture or color and a sore or nodule may develop on your skin. These skin changes usually can be seen with the naked eye, and 90% can be cured if treated early.

High-risk professions for skin cancer include farmers, vehicle drivers (their sun-exposed arm), and other sun- exposed outdoor workers.

There are three common types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and melanoma.

Basal cell carcinoma accounts for over 75% of all skin cancers. It usually occurs in middle-aged and elderly persons, especially those who are fair-skinned. It is more common in occupations with prolonged sun exposure. Basal cell carcinoma develops slowly and causes a lump or a small, painless, smooth-edged ulcer. It most often occurs on the face, head, and neck.

Squamous cell carcinoma also results from excessive sun exposure. In addition, pipe and cigar smoking and some petroleum products can cause squamous cell carcinoma. It may occur anywhere on the body as a small, usually painless (but sometimes bleeding), enlarging skin ulcer or irregularity. It is common around the mouth and on the lip.

Basal cell carcinoma has a very small likelihood of spread to other areas of the body. Squamous cell carcinoma spreads about 20% of the time. Both basal cell carcinoma and squamous cell carcinoma have excellent cure rates when treated promptly.

A melanoma usually develops from an existing mole. Melanoma is not as common as the other two types of skin cancer, but it is more serious and its treatment is different. Melanoma is explained in a separate handout.

How does it occur?

The most common and easily preventable cause of skin cancer is exposure to ultraviolet light (sunlight or tanning beds). Genetic (hereditary) factors play a part in the tendency to develop skin cancer. Some diseases and some chemicals increase a person's risk of developing skin cancer. Also, if you have another type of cancer, the cancer may spread to your skin.

What are the symptoms?

Many skin cancers occur on the face, but they can appear anywhere on the skin. Symptoms of skin cancer may include:

• sores or changes in the skin that do not heal

• a craterlike lesion (ulcer) on the skin that may not hurt

• change in color on part of the skin

• bleeding

• itching

• pain.

How is it diagnosed?

Your doctor diagnoses skin cancer by:

• looking at your skin

• taking your medical history and asking you if the affected area of skin has changed in any way

• performing a small biopsy (removing a small piece of tissue for microscopic analysis) or an excisional biopsy (removing the entire growth) for analysis if suspicious areas are present.

How is it treated?

The treatment is removal of the growth using one or more of the following procedures:

• shaving off the growth flat with the skin surface, then cauterizing (electrically burning) the surrounding area

• cutting out the affected area and closing the wound with sutures

• Mohs' chemosurgery (a method of removing and analyzing layers of the growth and surrounding skin)

• freezing the affected area using liquid nitrogen.

Skin cancer that is untreated or partially treated may result in more severe cancer problems.

If you have previously had skin cancer, you are at a higher risk for developing skin cancer again. Skin cancers may recur in the same location. Your doctor will want to examine you at 6- to 12-month intervals. Also, see your doctor if you discover any new changes on your skin.

How long will the effects last?

The effects will last as long as the cancer cells exist and grow. Unless they are removed, the cancer cells can spread to internal organs. Learn the characteristics of potentially dangerous skin growths, and see your doctor at the first sign of anything suspicious forming on your skin.

How can I help prevent skin cancer?

Avoid being exposed to too much sunlight. Wear clothing and hats that cover you, and avoid mid-day sun whenever possible. Use sunscreen lotions to protect against ultraviolet light when you must be outdoors. The higher the SPF (sun protection factor), the greater the protection. Use a lotion with an SPF value of at least 15. If you are allergic to PABA, use PABA-free sunscreen lotions. And remember that ultraviolet rays can penetrate clouds and cause sunburn or damage even on cloudy days.

If you are at high risk because of previous or ongoing sun exposure, see your health care provider for a baseline skin exam.

If you have a history of sun-related skin changes, such as actinic (solar) keratoses, see your doctor regularly on a schedule he or she recommends.

To get more information about skin cancer, talk to your doctor or contact the American Cancer Society chapter in your area.