Skin Cancer

Skin cancer is the most common of all cancers, with doctors finding skin cancer in about one million Americans each year. Reducing exposure to ultraviolet (UV) radiation from sunlight can prevent most skin cancers. If skin cancer is found early, it can usually be cured by relatively simple surgery. Skin cancer is responsible for less than 1% of all cancer deaths.

The skin, the body's largest organ, protects against infection and injury and helps regulate body temperature. The skin also stores water and fat and produces vitamin D. Skin is made up of two main layers: the epidermis (outer layer of skin) and the dermis (inner layer of skin).

Types of skin cancer

Cancer begins when normal cells change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body). There are three main types of skin cancer:

Squamous cell carcinoma. Most of the epidermis is made up of flat, scale-like cells called squamous cells. Approximately 20% of skin cancer resembles these cells and is called squamous cell carcinoma. This type of cancer is mainly caused by sun exposure, but it can appear on skin that has been burned, damaged by chemicals, or exposed to x-rays.

Basal cell carcinoma. Cells in the lower epidermis are round cells known as basal cells. About 80% of skin cancer develops from this type of cell that has been exposed to the sun and is called basal cell carcinoma. Basal cell carcinoma most often forms on the head and neck.

Melanoma. Where the epidermis meets the dermis, there are scattered cells called melanocytes, which produce the melanin that gives skin color. Melanoma starts in melanocytes, and it is the most aggressive of the three types of skin cancer. Learn more about melanoma. The rest of this section describes basal cell and squamous cell skin cancers.

Squamous cell carcinoma and basal cell carcinoma are known as non-melanoma skin cancers, to distinguish them from melanoma, which arises from very different cells and is treated differently.

Typically, non-melanoma skin cancer can be treated with relatively simple surgery. If the cancer is very small, cryosurgery (freezing) or laser surgery may be used. Learn more in the Treatment section. Basal cell carcinoma grows slowly and rarely metastasizes (spreads) to other parts of the body. Squamous cell carcinoma also rarely spreads, but it is more likely to spread than basal cell carcinoma.

Symptoms and Signs

People with basal cell or squamous cell carcinoma may experience the following symptoms. Sometimes, people with non-melanoma skin cancer do not show any of these symptoms or signs. Or, these symptoms may be caused by a medical condition that is not cancer. The skin features that people with basal cell or squamous cell carcinoma frequently develop are listed below. If you are concerned about a symptom or skin feature, please talk with your doctor.

Changes in the skin are the main warning sign for skin cancer. Each type of skin cancer can appear differently, so it is important to talk with your doctor when you notice a change in your skin.

For basal cell cancer, two or more of the following features may be present:

• An open sore that bleeds, oozes, or crusts and remains open for several weeks
• A reddish, raised patch or irritated area that may crust or itch, but rarely hurts
• A shiny pink, red, pearly white, or translucent bump
• A pink growth with an elevated border and crusted central indentation
• A scar-like, white, yellow, or waxy area, often with a poorly defined border

Squamous cell cancer can often crust, bleed, and appear as:

• A wart-like growth
• A persistent, scaly red patch with irregular borders that may bleed easily
• An open sore that persists for weeks
• An elevated growth with a rough surface and a central depression

Your doctor will ask you questions about the symptoms you are experiencing to help find out the cause of the problem, called a diagnosis. This may include how long you've been experiencing the symptom(s) and how often.

If cancer is diagnosed, relieving symptoms and side effects remains an important part of cancer care and treatment. This may also be called symptom management, palliative care, or supportive care. Be sure to talk with your health care team about symptoms you experience, including any new symptoms or a change in symptoms.

Early detection: Finding skin cancer early

Earlier detection and recognition of skin cancer is the key to improving the chance for successful treatment. Recognizing early warning signs of skin cancer and doing regular self-examinations of your skin will help find skin cancer early when the disease is highly curable.

Examinations should be performed in front of a full-length mirror in a brightly lit room. It helps to have another person check the scalp and back of the neck. In people with fair skin, non-melanoma skin cancer most often begins on skin that has frequently been exposed to the sun. However, in people with darker skin, squamous cell carcinoma occurs primarily in areas infrequently exposed to the sun, such as the lower legs.

Include the following steps in a skin self-examination:

• Examine the front and back of the entire body in a mirror, then the right and left sides, with arms raised.
• Bend the elbows and look carefully at the outer and inner forearms, upper arms (especially the hard-to-see back portion), and hands.
• Look at the front, sides, and back of the legs and feet, including the soles and the spaces between the toes.
• Part the hair to lift it and examine the back of the neck and scalp with a hand mirror.
• Check the back, genital area, and buttocks with a hand mirror.

Talk with your doctor if you find any of the following:

• A growth on the skin that matches any symptom listed above
• New growth on the skin
• A suspicious change in an existing mole or spot
• A sore that doesn't heal within two weeks