Skin Cancer [Basal Cell Carcinoma : Squamous Cell Carcinoma]

Definition

Skin cancer is a disease in which cancer cells grow in the skin.

The two most common kinds of skin cancer are:


Basal Cell Carcinoma – a slow-growing cancer that begins in the inner layer of the skin and rarely spreads to other parts of the body. It accounts for more than 90% of all skin cancers in the United States.

Squamous Cell Carcinoma –a cancer that starts in the outer layer of the skin. It also rarely spreads, but does so more often than basal cell carcinoma.


Cancer occurs when cells in the body (in this case skin cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissues and can spread to other parts of the body. A benign tumor is unable to invade or spread.
It is important that skin cancers be found and treated early because they can invade and destroy nearby tissue. Another type of cancer that occurs in the skin is melanoma. For information about melanoma, see the melanoma fact sheet.

Causes

In genetically susceptible people, ultraviolet radiation from the sun is the main cause of skin cancer. But artificial radiation from sun lamps and tanning booths can also cause skin cancer.

Actinic (solar) keratosis is a precancerous lesion resulting from the accumulated exposure to ultraviolet radiation from the sun. If left untreated, it may progress to squamous cell carcinoma, which occurs approximately 10% of the time.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

• Fair skin that freckles easily
• Red or blonde hair
• Light-colored eyes
• Age: 50 or older
• Sex: Male
• Race: White people who live in places where the sun's rays are strong year-round
• Excessive sun exposure without protective clothing or sunscreen
• Exposure to arsenic, industrial tar, coal, paraffin, and certain types of oil
• Radiation treatment
• Certain treatments for psoriasis

Symptoms

Skin cancers are rarely painful. The most common first symptom of skin cancer is a change in the skin, such as a new growth or a sore that doesn't heal. When it starts, skin cancer may appear as:

• A small, smooth, shiny, pale, or waxy lump
• A firm red lump
• A lump that bleeds or develops a crust
• A flat, red spot that is rough, dry, or scaly

Skin cancers are found mainly on areas of the skin that are exposed to the sun: the head, face, ears, neck, hands, and arms. However, skin cancer can occur anywhere.

Note: These symptoms may also be caused by other, less serious health conditions. A person experiencing these symptoms should see a doctor if they last for more than 2 weeks.

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam. If you have a growth like those listed above, your doctor may treat it in the office. This involves removing all or part of the lesion and sending it to the laboratory for a biopsy.

In cases where the growth is very large or has been present for a long time, the doctor will carefully check the lymph nodes in the area. In addition, you may need to have additional tests to find out if the cancer has spread to other parts of the body.

Treatment

Treatment for skin cancer usually involves surgery. In some cases, radiation therapy or chemotherapy may be used. Sometimes a combination of methods is used.
Treatments include:

Surgery

Many skin cancers can be cut from the skin quickly and easily. In fact, the cancer is sometimes completely removed at the time of the biopsy, and no further treatment is needed. Surgical techniques include:

Curettage and Electrodesiccation – Removal of the cancer by scooping it out with a curette, an instrument with a sharp, spoon-shaped end. The area is also treated with an electric current to control bleeding and kill any cancer cells remaining around the edge of the wound.

Mohs' Technique –Removal of all of the cancerous tissue and as little of the healthy tissue as possible. This method is used to remove large tumors, those in hard-to-treat places, tumors of undetermined shape and depth, and cancers that have recurred. The cancer is shaved off one thin layer at a time. Each layer is checked under a microscope for cancer cells until the entire tumor is removed.

Cryosurgery –Liquid nitrogen is used to freeze and kill the abnormal cells. After the area thaws, the dead tissue falls off. More than one freezing may be needed to remove the growth completely. Cryosurgery usually does not hurt, but patients may have pain and swelling after the area thaws. This method may be used to treat precancerous skin conditions (actinic keratoses) as well as certain small skin cancers.

Laser Therapy

Laser therapy uses a narrow beam of light to remove or destroy cancer cells. This method is sometimes used for cancers that involve only the outer layer of skin.

Grafting

When a large cancer is removed, a skin graft is needed to close the wound and reduce the amount of scarring. The doctor takes a piece of healthy skin from another part of the body to replace the skin that was removed.

Radiation Therapy (Radiotherapy)

Radiation therapy uses radiation to kill cancer cells and shrink tumors.

Topical Chemotherapy

Topical chemotherapy is the use of drugs, in the form of cream or lotion, to kill cancer cells. This method is particularly successful in treating pre-cancerous conditions and cancers limited to the outer layer of the skin.

Prevention

Prevention includes:

• Avoid spending too much time in the sun.
• Protect your skin from the sun with clothing, including a shirt, sunglasses, and a hat with a broad brim.
• Use sunscreens with a sun protection factor (SPF) of 15 or more on skin that will be exposed to the sun.
• Avoid exposing your skin to the sun between 10 a.m. and 2 p.m. standard time, or 11 a.m. and 3 p.m. daylight saving time.
• Don't use sun lamps or tanning booths.
Take the following precautions to find skin cancer early:
• If you have any of the symptoms listed above, have your skin examined by a doctor.
• If you have fair skin, have your skin checked by a doctor.
• Learn how to do skin self exam