Diseases and Skin Conditions

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Skin Cancer

The most common cancer in the world

More than 2 million cases of skin cancer will be diagnosed this year. And that’s just in the United States. Most Americans will have one of these skin cancers:

  • Basal (bay-sal) cell carcinoma
  • Squamous (skwey-muhs) cell carcinoma
  • Melanoma

Who gets skin cancer?

Anyone can get skin cancer. Even people who have skin of colour get this cancer. Bob Marley, a musician from Jamaica, developed melanoma on his foot. Most people who get skin cancer, however, have lighter skin.

People who are more likely to get skin cancer:

  • Spend a lot of time in the sun.
  • Use tanning beds or sun lamps.
  • Live (or once lived) in an area that gets intense sunlight, such as Florida, the Caribbean, or northern Australia.

If this exposure was years ago, a person still has an increased risk. Even if the exposure did not last long, such as lying out for a few summers, there is a greater risk.

Risk factors for skin cancer

Scientists have found that the following increases a person’s risk for getting skin cancer.

Skin: A person’s skin type and the moles on one’s skin affect the person’s risk for getting skin cancer. The risk increases when the person has:

  • Fair skin, especially when the person also has blond or red hair and blue, green, or grey eyes.
  • Had bad sunburns, especially blistering sunburns.
  • Skin that burns or freckles rather than tans.
  • 50-plus moles.
  • Moles called “atypical nevi” or “dysplastic nevi.”

Family: When a close blood relative has (or had) skin cancer, a person’s risk of getting skin cancer rises. A close blood relative is a parent, brother, sister, or child.

Medical history: Having (or having had) any of the following puts a person at greater risk for getting skin cancer:

  • Previous skin cancer.
  • Actinic keratoses (AKs). Having AK’s means the skin has lots of damage. This damage increases the risk of getting all types of skin cancer. Sometimes, an AK can progress to a type of skin cancer called squamous cell carcinoma.
  • Organ transplant. The medicine that prevents the body from rejecting the organ also weakens the immune system. A weak immune system increases the risk of skin cancer.
  • Bad burn. Skin cancer can develop where the skin has been badly burned.
  • X-ray treatments. Receiving many x-ray treatments to treat a medical condition increases the risk. This takes many years to develop.
  • Disease that weakens the immune system. Lymphoma and human immunodeficiency virus (HIV) are a few diseases that weaken the immune system.
  • Xeroderma pigmentosum. People who inherit this rare disease get many skin cancers.
  • Gorlin’s syndrome (also called basal cell nevus syndrome). People who have this rare disease can get many basal cell carcinomas early in life. They also have a higher risk for getting melanoma and non-Hodgkin's lymphoma.

Exposure to chemicals: People exposed to any of the following have a much higher risk of skin cancer:

  • Arsenic (working with or swallowing).
  • Coal.
  • Industrial tar.

Tobacco: Smoking or chewing tobacco may increase the risk of getting squamous cell carcinoma, a type of skin cancer, in the mouth or throat

Actinic / Solar Keratoses (AK’s)

These are considered the earliest stage in the development of skin cancer. They are small scaly spots most commonly found on the face, ears, neck, lower arms, and back of the hands in fair-skinned individuals who have had significant sun exposure.

AK’s can be treated by cryotherapy (freezing), topical chemotherapy (applying a cream), chemical peeling, dermabrasion, laser surgery, curettage, photodynamic therapy (a chemical is applied to the skin prior to exposure to a light source) or other dermatologic surgical procedures.

Some AK’s may progress to advanced stages that require more extensive treatment. Proper use of sunscreens can help prevent AK’s even after extensive sun damage has already occurred.

Basal cell carcinoma (BCC)

This is the most common type of skin cancer. It most often appears on skin that gets lot of sun, such as the face, scalp, neck, hands, and arms. You will find BCC’s on other parts of the body, too.

It can appear on parts of the body that did not get lots of sun, such as the genitals. This skin cancer appears in many shapes and sizes.

BCC often grows slowly. It may look like a:

  • Reddish patch of dry skin that won’t heal
  • Flesh-coloured (or pink, red, or brown) pearl-shaped lump
  • Pimple that just won’t clear
  • Sore that bleeds, heals, and then returns
  • Scar that feels waxy — may be skin-coloured, white, or yellow
  • Group of slow-growing, shiny pink or red growths — look like sores, often scaly and bleed easily
  • Flat or sunken growth — feels hard, may be white or yellow

Squamous cell carcinoma (SCC)

This is the 2nd most common type of skin cancer. It is primarily found in fair skinned individuals and rarely in dark skinned individuals.

It often appears on skin that got lots of sun, such as an ear, face, bald scalp, neck, or arm. But it can appear elsewhere — even inside the mouth, on the lip, or on the genitals.

Too much sun is often the cause, but it is not the only cause. SCC can appear on skin that was badly burned, had lots of radiation (such as x-rays), or was exposed to strong chemicals.

SCC often has a reddish colour. Without treatment, it can grow deeply. If this happens, the cancer can spread to other parts of the body. This can be deadly. SCC often looks like a:

  • Hard (scaly or crusty) reddish bump, patch, or pearl-shaped growth
  • Open sore that itches and bleeds; it can heal and return
  • Scaly patch on the lip; skin on the lip can get thick

SCC can develop into large masses and become invasive. Unlike BCC, SCC can metastasize (spread) to other parts of the body, therefore it is important to get early treatment. When found early and treated properly, cure rates are high.


Malignant melanoma is the most deadly of all skin cancers. Every year an estimated 8000 Americans will die from melanoma; more than 108 000 Americans will develop melanoma annually.

Melanoma develops in melanocytes, the skin cells that produce the dark protective pigment called melanin which makes skin tan. Since melanoma cells usually continue to produce melanin, the cancer appears in mixed shades of tan, brown, and black; although, it can also be red or white.

Know where you have moles on your skin! Melanoma often appears in an existing mole or looks like a new mole. By knowing where you have moles on your skin, you can find melanoma when it first appears. Melanoma can metastasize making early detection and treatment essential. When treated early, melanoma is often curable.

Here’s what to look for:

  • A mole on the skin that is growing, changing shape, or changing colour
  • A mole that looks scaly, oozes, or bleeds
  • New dark spot on the skin that looks like a mole, but grows quickly
  • Pain, itch, or bleeding in a new spot on the skin
  • Streak (usually brown or black) underneath a fingernail or toenail
  • Bruise on the foot that does not heal

What skin cancer looks like?

Even the same type of skin cancer can look very different from person to person. This makes it hard to look at a picture and tell if you have skin cancer.

The best way to tell if you have skin cancer is to see a dermatologist. You should see a dermatologist right away for a skin cancer check if you see anything on your skin that lasts for 2 weeks or longer and is:

  • Growing
  • Changing shape
  • Bleeding or itching

These are signs of skin cancer. If it is caught early and removed, skin cancer has a high cure rate.

How do dermatologists diagnose skin cancer?

To diagnose skin cancer, a dermatologist looks at the skin. A dermatologist will carefully examine growths, moles, and dry patches.

To get a better look, a dermatologist may use a device called a dermatoscope. The device shines light on the skin. It magnifies the skin. This helps the dermatologist to see pigment and structures in the skin.

If a dermatologist finds something that looks like skin cancer, the dermatologist will remove it (or part of it). The removed skin will be sent to a lab. Your dermatologist may call this a biopsy. Skin cancer cannot be diagnosed without a biopsy.

A biopsy is quick, safe, and easy for a dermatologist to perform. A biopsy should not cause anxiety. The discomfort and risks are minimal.

How do dermatologists treat skin cancer?

There are many treatments for skin cancer. A dermatologist selects treatment after considering the following:

  • Type of skin cancer
  • Where the skin cancer appears on the body
  • Whether the skin cancer is aggressive
  • Stage of the cancer (how deeply the skin cancer has grown and whether it has spread)
  • Patient’s health

After considering the above, your dermatologist will choose 1 or more of the following treatments for skin cancer.

Surgical treatment: When treating skin cancer, the goal is to remove all of the cancer. When the cancer has not spread, this is often possible. To remove skin cancer, the following surgical treatment may be used:

  • Excision: To perform this, the dermatologist numbs the skin and then surgically cuts out the skin cancer and a small amount of normal-looking skin. This normal-looking skin is called a margin.

    There are different types of excision. Most excisions can be performed in a dermatologist’s office.

  • Moh’s surgery: A dermatologist who has completed additional medical training in Moh’s surgery performs this procedure. Once a dermatologist completes this training, the dermatologist is called a Moh’s surgeon.

    Moh’s surgery begins with the surgeon removing the visible part of the skin cancer. Because cancer cells are not visible to the naked eye, the surgeon also removes some skin that looks normal but may contain cancer cells.

    This part of the surgery is performed one layer at a time. After removing a layer of skin, it is prepared so that the surgeon can examine it under a microscope and look for cancer cells.

    If the surgeon sees cancer cells, the surgeon removes another layer of skin. This layer-by-layer approach continues until the surgeon no longer finds cancer cells. In most cases, Moh’s surgery can be completed within a day or less. The cure rate for skin cancer is high when Moh’s surgery is used.

  • Curettage and electrodesiccation: This surgical procedure may be used to treat small basal cell and squamous cell skin cancers.

    It involves scraping the tumour with a curette (a surgical instrument shaped like a long spoon) and then using an electric needle to gently cauterize (burn) the remaining cancer cells and some normal-looking tissue. This scraping and cauterizing process is typically repeated 3 times. The wound tends to heal without stitches.

    Sometimes, curettage is used alone.

Other treatments: Surgical treatment is not right for every case of skin cancer. Some patients cannot undergo surgery. Sometimes, surgery cannot remove all of the cancer, and more treatment is used to help get rid of the cancer. If the skin cancer is caught very early, surgery may not be necessary.

Other treatments for skin cancer are:

  • Immunotherapy: This treatment uses the patient’s own immune system to fight the cancer. The patient applies a cream to the skin as directed by the dermatologist.
  • Cryosurgery: The dermatologist freezes the skin cancer. Freezing destroys the treated area, causing the skin and cancer cells to slough off.
  • Chemotherapy applied to the skin: The patient applies a cream or an ointment to the skin cancer. It destroys the damaged skin cells. When the skin heals, new skin appears.
  • Chemotherapy: If the cancer spreads beyond the skin, chemotherapy may kill the cancer cells. When a patient gets chemotherapy, the patient takes medicine. This medicine may be swallowed, injected (shots), or infused (given with an IV).

    The medicine travels throughout the body and kills the cancer cells. The medicine also destroys some normal cells. This can cause side effects, such as vomiting and hair loss. When chemotherapy stops, the side effects usually disappear.

  • Photodynamic therapy: This treatment consists of 2 phases. First, a chemical is applied to the skin cancer. This chemical sits on the skin cancer for several hours. During the second phase, the skin cancer is exposed to a special light. This light destroys the cancer cells.
  • Radiation therapy: Radiation may be used to treat older adults who have a large skin cancer, skin cancers that cover a large area, or a skin cancer that is difficult to surgically remove. Radiation therapy gradually destroys the cancer cells through repeat exposure to radiation. A patient may receive 15 to 30 treatments.

    This treatment is often only recommended for older adults. Many years after a person is exposed to radiation, new skin cancer can develop.

What outcome can someone with skin cancer expect?

If it is caught early and properly treated, skin cancer can be cured. Even melanoma, which can be deadly, has a cure rate of almost 100% when treated early.

Even if you get a clean bill of health, you need to continue to see your dermatologist. Once a person gets skin cancer, the risk of getting another skin cancer is higher. Sometimes skin cancer returns. Your dermatologist will tell you how often you should return for check-ups.

Without early treatment, the outcome is not as favourable. Skin cancer can grow deeply. Removing the cancer can mean removing muscle and even bone. Reconstructive surgery may be needed after the surgery to remove the skin cancer. And skin cancer can spread.

If the cancer spreads, treatment can be difficult. Treatment may not cure cancer that spreads.

Skin cancer: Tips for preventing and finding

Dermatologists share these tips with their patients. These tips can help you prevent skin cancer — or find skin cancer early when treatment can cure the skin cancer.

Preventing skin cancer
  • Never use a tanning bed or sun lamp. These can cause skin cancer. Research shows that using a tanning bed increases your risk of getting melanoma by 75 percent. If you want to look like you have been in the sun, use a sunless self-tanning product , but continue to use a sunscreen with it.
  • Wear sunscreen and lip balm every day. The sun is a known cause of skin cancer. Every day, before you go outside, apply sunscreen to all skin that will be bare (face, ears, hands, neck, etc.). Apply lip balm to your lips. Be sure to use sunscreen that:
    • Protects against UVA and UVB rays. The label must say broad-spectrum or UVA/UVB protection. If it does not say either, find another product.
    • Has a sun protection factor (SPF) of at least 30.
    • Reapply every 2 hours, even on cloudy days, and after swimming or sweating.
  • Wear clothes that protect you from UV rays. Wear a long sleeved shirt, pants and a wide brimmed hat, where possible. A jean jacket offers great UV protection. A white t-shirt does not. Any clothing that you can hold up to bright light and see through does not offer the protection you need.

    To boost the UV protection that your clothes offer, you may want to use a UV protectant. You wash this protectant into your clothes. To use, you simply add it to the wash cycle.

  • Wear sunglasses that offer UV protection every day. Melanoma can develop in the eyes.
  • Try not to spend time outdoors between 10 a.m. and 4 p.m. This is when the sun is strongest.
  • Use extra caution near water, snow or sand as they reflect the damaging rays of the sun which can increase your chance of sunburn

Finding skin cancer

  • Perform skin self-exams. This can help you find skin cancer early when it can be cured. These exams are especially important if you have been treated for skin cancer. Early detection and removal offer the best chance of cure. Periodic self-examinations aid in recognition of new or developing lesions. Get familiar with your skin and your own pattern of moles, freckles and “beauty marks”.

    Make sure you look at your entire body every month or two. Watch for changes in the number, size, shape, and colour of pigmented areas. Consults your dermatologist promptly if any changes are noticed. Individuals at high risk should be examined by a dermatologist on a regular basis.

    It is beneficial to get assistance from a partner in performing skin self exams.

    • Examine body front and back in mirror, then right and left sides, arms raised
    • Bend elbows, look carefully at forearms, back of upper arms and palms
    • Next, look at back of the legs and feet, spaces between toes and soles
    • Examine back of neck and scalp with a hand mirror. Part hair to lift.
    • Finally, check back and buttocks with a hand mirror

    If you see something that looks like skin cancer, make an appointment to see a dermatologist. The earlier skin cancer is caught and treated, the more likely it can be cured.

  • Get screened for skin cancer. How often you need to get screened varies from person to person.
  • If you have never been screened for skin cancer, you may want to ask your primary care doctor whether you need to see a dermatologist for a skin cancer screening.

    If your doctor recommends that you see a dermatologist, be sure to ask the dermatologist how often you should have a skin cancer screening. Some people need to be screened more often than others do.

  • If you have been treated for skin cancer, keep all follow-up appointments with your doctors. The earlier skin cancer is caught and treated, the greater the chance of a cure.
  • Check your birthday suit on your birthday. If you notice anything changing, growing or bleeding, see a dermatologist.

Support groups and other resources

Learning that you have skin cancer can be frightening. You do not have to face this alone. A support group can help.

Related Links

Basal cell carcinoma

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