There are three main types of skin cancer:

 

Melanoma

Basal cell skin cancer

Squamous cell skin cancer

 

Of these, melanoma is the least common and most aggressive kind. There is a separate article on melanoma. The rest of this article is specifically about basal cell skin cancer and squamous cell skin cancer, which are collectively known as nonmelanoma skin cancer.

 

Understanding skin cancer

Skin cancer begins in cells, the building blocks that make up the skin. Normally, skin cells grow and divide to form new cells. Every day skin cells grow old and die, and new cells take their place.

 

Sometimes, this orderly process goes wrong. New cells form when the skin doesn't need them, and old cells don't die when they should. These extra cells can form a mass of tissue called a growth or tumor.

 

Growths or tumors can be benign or malignant:

 

Benign growths are non-cancerous:

     · Benign growths are rarely life-threatening.
     · Generally, benign growths can be removed. They usually do not grow back.
     · Cells from benign growths do not invade the tissues around them.
     · Cells from benign growths do not spread to other parts of the body.

Malignant growths are cancerous:
     · Malignant growths are generally more serious than benign growths. They may be life-threatening. However, the two most common types of skin cancer cause only about one out of every thousand deaths from cancer.
     · Malignant growths often can be removed. But sometimes they grow back.
     · Cells from malignant growths can invade and damage nearby tissues and organs.
     · Cells from some malignant growths can spread to other parts of the body. The spread of cancer is called metastasis.

 

Skin cancers are named for the type of cells that become cancerous. Basal cell cancer and squamous cell cancer and the two commonest kinds. These cancers usually form on the head, face, neck, hands, and arms. These areas are exposed to the sun. But skin cancer can occur anywhere.

 

Basal cell skin cancer grows slowly. It usually occurs on areas of the skin that have been in the sun. It is most common on the face. Basal cell cancer rarely spreads to other parts of the body.

 

Squamous cell skin cancer also occurs on parts of the skin that have been in the sun. But it also may be in places that are not in the sun. Squamous cell cancer sometimes spreads to lymph nodes and organs inside the body.

 

If skin cancer spreads from its original place to another part of the body, the new growth has the same kind of abnormal cells and the same name as the primary growth. It is still called skin cancer.

 

Risk factors

Doctors cannot explain why one person develops skin cancer and another does not. However, we do know that skin cancer is not contagious. You can't catch it from another person.

 

Research has shown that people with certain risk factors are more likely than others to develop skin cancer. A risk factor is something that may increase the chance of developing a disease.

 

Studies have found the following risk factors for skin cancer:

 

Ultraviolet (UV) radiation: UV radiation comes from the sun, sunlamps, tanning beds, or tanning booths. A person's risk of skin cancer is related to lifetime exposure to UV radiation. Most skin cancer appears after age 50, but the sun damages the skin from an early age.

 

UV radiation affects everyone. But people who have fair skin that freckles or burns easily are at greater risk. These people often also have red or blond hair and light-colored eyes. But even people who tan can get skin cancer.

 

People who live in areas that get high levels of UV radiation have a higher risk of skin cancer. In the United States, areas in the south (such as Texas and Florida) get more UV radiation than areas in the north (such as Minnesota). Also, people who live in the mountains get high levels of UV radiation.

 

UV radiation is present even in cold weather or on a cloudy day.

 

Scars or burns on the skin

Infection with certain human papillomaviruses

Exposure to arsenic at work

Chronic skin inflammation or skin ulcers

Diseases that make the skin sensitive to the sun, such as xeroderma pigmentosum, albinism (see albino), and basal cell nevus syndrome

Radiation therapy

Medical conditions or drugs that suppress the immune system

Personal history of one or more skin cancers

Family history of skin cancer

Actinic keratosis: Actinic keratosis is a type of flat, scaly growth on the skin. It is most often found on areas exposed to the sun, especially the face and the backs of the hands. The growths may appear as rough red or brown patches on the skin. They may also appear as cracking or peeling of the lower lip that does not heal. Without treatment, a small number of these scaly growths may turn into squamous cell cancer.

Bowen's disease: Bowen's disease is a type of scaly or thickened patch on the skin. It may turn into squamous cell skin cancer.

 

If you think you may be at risk for skin cancer, you should discuss this concern with your doctor. Your doctor may be able to suggest ways to reduce your risk and can plan a schedule for checkups.

 

Prevention

The best way to prevent skin cancer is to protect yourself from the sun. Also, protect children from an early age. Doctors suggest that people of all ages limit their time in the sun and avoid other sources of UV radiation:

 

It is best to stay out of the midday sun (from mid-morning to late afternoon) whenever you can. You also should protect yourself from UV radiation reflected by sand, water, snow, and ice. UV radiation can go through light clothing, windshields, windows, and clouds.

Wear long sleeves and long pants of tightly woven fabrics, a hat with a wide brim, and sunglasses that absorb UV.

Use sunscreen lotions. Sunscreen may help prevent skin cancer, especially broad-spectrum sunscreen (to filter UVB and UVA rays) with a sun protection factor (SPF) of at least 15. But you still need to avoid the sun and wear clothing to protect your skin.

Stay away from sunlamps and tanning booths.

 

Symptoms

Most basal cell and squamous cell skin cancers can be cured if found and treated early.

 

A change on the skin is the most common sign of skin cancer. This may be a new growth, a sore that doesn't heal, or a change in an old growth. Not all skin cancers look the same. Skin changes to watch for:

 

Sometimes skin cancer is painful, but usually it is not.

 

Checking your skin for new growths or other changes is a good idea. A guide for checking your skin is below. Keep in mind that changes are not a sure sign of skin cancer. Still, you should report any changes to your health care provider right away. You may need to see a dermatologist, a doctor who has special training in the diagnosis and treatment of skin problems.

 

Diagnosis

If you have a change on the skin, the doctor must find out whether it is due to cancer or to some other cause. Your doctor removes all or part of the area that does not look normal. The sample goes to a lab. A pathologist checks the sample under a microscope. This is a biopsy. A biopsy is the only sure way to diagnose skin cancer.

 

You may have the biopsy in a doctor's office or as an outpatient in a clinic or hospital. Where it is done depends on the size and place of the abnormal area on your skin. You probably will have local anesthesia.

 

There are four common types of skin biopsies:

 

Punch biopsy: The doctor uses a sharp, hollow tool to remove a circle of tissue from the abnormal area.

Incisional biopsy: The doctor uses a scalpel to remove part of the growth.

Excisional biopsy: The doctor uses a scalpel to remove the entire growth and some tissue around it.

Shave biopsy: The doctor uses a thin, sharp blade to shave off the abnormal growth.

 

You may want to ask your doctor these questions before having a biopsy:

 

Which type of biopsy do you recommend for me?

How will the biopsy be done?

Will I have to go to the hospital?

How long will it take? Will I be awake? Will it hurt?

Are there any risks? What are the chances of infection or bleeding after the biopsy?

What will my scar look like?

How soon will I know the results? Who will explain them to me?

 

Staging

If the biopsy shows that you have cancer, your doctor needs to know the extent (stage) of the disease. In very few cases, the doctor may check your lymph nodes to stage the cancer.

 

The stage is based on:

 

The size of the growth

How deeply it has grown beneath the top layer of skin

Whether it has spread to nearby lymph nodes or to other parts of the body

 

These are the stages of skin cancer:

 

Stage 0: The cancer involves only the top layer of skin. It is carcinoma in situ.

Stage I: The growth is 2 centimeters wide (three-quarters of an inch) or smaller.

Stage II: The growth is larger than 2 centimeters wide (three-quarters of an inch).

Stage III: The cancer has spread below the skin to cartilage, muscle, bone, or to nearby lymph nodes. It has not spread to other places in the body.

Stage IV: The cancer has spread to other places in the body.

For treatment options, go to the article on skin cancer treatment.

 

Skin self-exam

Your doctor or nurse may suggest that you do a regular skin self-exam to check for skin cancer, including melanoma.

 

The best time to do this exam is after a shower or bath. You should check your skin in a room with plenty of light. You should use a full-length mirror and a hand-held mirror. It's best to begin by learning where your birthmarks, moles, and other marks are and their usual look and feel.

 

Check for anything new:

 

New mole (that looks different from your other moles)

New red or darker color flaky patch that may be a little raised

New flesh-colored firm bump

Change in the size, shape, color, or feel of a mole

Sore that does not heal

 

Check yourself from head to toe. Don't forget to check your back, scalp, genital area, and between your buttocks.

 

Look at your face, neck, ears, and scalp. You may want to use a comb or a blow dryer to move your hair so that you can see better. You also may want to have a relative or friend check through your hair. It may be hard to check your scalp by yourself.

Look at the front and back of your body in the mirror. Then, raise your arms and look at your left and right sides.

Bend your elbows. Look carefully at your fingernails, palms, forearms (including the undersides), and upper arms.

Examine the back, front, and sides of your legs. Also look around your genital area and between your buttocks.

Sit and closely examine your feet, including your toenails, your soles, and the spaces between your toes.

 

By checking your skin regularly, you will learn what is normal for you. It may be helpful to record the dates of your skin exams and to write notes about the way your skin looks. If your doctor has taken photos of your skin, you can compare your skin to the photos to help check for changes. If you find anything unusual, see your doctor.