HealthyCanada.com

Overview

Skin cancer · the abnormal growth of skin cells · is the most commonly occurring cancer accounting for about one third of all cases. There are three major types: basal cell squamous cell and melanoma. While the incidence and death rates for the majority of cancers in Canada are stabilizing or declining skin cancer rates are on the rise. The good news is that in most cases skin cancer is preventable and if caught early highly treatable.

Causes

Basal cell and squamous cell are the two most common skin cancers. Both are superficial slow growing and highly treatable especially if found early. Melanoma is a more serious form of skin cancer. It affects deeper layers of the skin and has the greatest potential to spread to other tissues and organs in your body. All three types of skin cancer are caused at least in part by long-term exposure to the sun's ultraviolet radiation or UV rays which penetrate and damage the skin over time. Every time you get a sun burn you increase your risk of developing skin cancer. Anyone who has had one or more severe blistering sunburns as a child or teenager is at increased risk of skin cancer as an adult. Other risk factors include:

Fair Skin - Skin pigment (melanin) acts as a shield against the sun's damaging rays. Darker skinned people have more protection than fair skinned people. Those with light hair and freckles are at especially high risk.

Moles -- People who have dysplastic nevi are at increased risk of skin cancer. These moles look irregular and are generally larger than normal moles. They may be more likely than others to become cancerous. Having many normal moles (more than 50) also increases the risk of developing skin cancer.

Family History -- The risk of developing skin cancer is greater if one or more close relatives has the disease.

Gender -- Men have a higher rate of skin cancer than women.

Age -- The likelihood of developing skin cancer increases with age. The rate of melanoma in 70-year-olds is twice that of 45-year-olds.

Weakened immune system -- People whose immune system is weakened by certain cancers by drugs given following organ transplantation or by HIV are at increased risk of developing melanoma.

The primary symptom of any skin cancer is usually a mole sore lump or growth on the skin. Any change in appearance of a pigmented skin lesion over time is a warning sign. Also watch for any bleeding from a skin growth.

The ABCDE system may help you remember features that might be a symptom of skin cancer:

• Asymmetry: One half of the abnormal area is different from the other half
• Borders: The lesion or growth has irregular edges.
• Colour: Colour is varied from one area to another with shades of tan brown or black (sometimes white red or blue). A mixture of colors may appear within one lesion.
• Diameter: The trouble spot is usually (but not always) larger than 6 mm in diameter -- about the size of a pencil eraser.
• Elevation: A mole that is raised above the skin and has an uneven surface

The key to treating skin cancer is recognizing symptoms early. You might not notice a small spot if you don't look carefully. Cancer can occur on any skin surface. In men it is often found on the trunk of the body (the area between the shoulders and the hips) or the head and neck. In women it often develops on the lower legs. When it develops in dark-skinned people it tends to occur under the fingernails or toenails or on the palms or soles. It is important to check your skin regularly. You should ask someone to help you check hard-to-get-at places such as your back back of your neck ears and backs of your legs. Look for:

• Birthmarks or moles that appear or existing ones that change shape colour size edge pattern or surface
• New growth on your skin - pale pearly modules that may grow larger and crust or red scaly sharply defined patches
• Sores that do not heal
• Patches of skin that bleed ooze swell itch or become red and bumpy

Ask your doctor for help if you notice changes to your skin or are confused about what you should be looking for. If skin cancer should develop early detection and treatment are the best defense.

Your doctor may suspect skin cancer based on the appearance of a growth sore or lump. A biopsy which involves removal of all or part of a small area of growth may be used to confirm the diagnosis. Subsequent treatments depend on the size type depth and location of the cancerous skin cells. If caught early the lesion or lesions can be surgically removed often in an outpatient setting using a local anesthetic. Only the smallest and most shallow melanomas can be cured by surgery alone. In other cases radiation therapy and chemotherapy may also be used. For patients with melanoma that has spread beyond the skin and lymph nodes to other organs treatment is more difficult. At this point it is usually not curable and treatment is usually directed at shrinking the tumour and improving symptoms.

Prevention

Many experts recommend that people stay out of the sun to avoid skin damage including melanoma. If you must be in the sun exercise "sun sense."

The Canadian Dermatology Association and the Canadian Cancer Society recommend that you:

• Reduce sun exposure between 11 a.m. and 4 p.m. The sun's rays are at their strongest between these hours. It's easy to remember - during these hours your shadow is shorter than you are. If you can plan your outdoor activities before 11 a.m. or after 4 p.m.
• Seek shade or create your own shade. When you are outside - especially between 11 a.m. and 4 p.m. - try to stay in the shade. Be prepared for places without any shade by taking along an umbrella. With an umbrella you can create shade wherever you need it.
• SLIP! on clothing to cover your arms and legs. Covering your skin will protect it from the sun. Choose clothing that is: loose fitting; tightly woven; and lightweight.
• SLAP! on a wide-brimmed hat. Most skin cancers occur on the face and neck. This area needs extra protection. Wear a hat with a wide brim that covers your head face ears and neck. Hats without a wide brim like baseball caps do not give you enough protection.
• SLOP! on a sunscreen with SPF (Sun Protection Factor) 15 or higher - SPF 30 if you work outdoors or if you will be outside for most of the day. Look for "broad spectrum" on the label. This means that the sunscreen offers protection against two types of ultraviolet rays UVA and UVB.
• Apply sunscreen generously 20 minutes before outdoor activities. Reapply often - at least every 2 hours (and after swimming or exercise that makes you perspire). No sunscreen can absorb all of the sun's rays. Use sunscreen along with shade clothing and hats - not instead of them. Use sunscreen as a backup in your sun protection plan.
• Keep babies under one year out of the direct sun. Babies need extra protection because their skin is very sensitive. Keep your child's stroller playpen or carriage in the shade.
• Tanning salons and sunlamps are not a safe way to tan. Tanning salons do not give you a "safe tan without burning". No tan is a safe tan. A tan is evidence of sun damage.

Additional Resources

Canadian Cancer Society

Canadian Dermatology Association

A Parent's Guide to Sun Protection (Health Canada)

Check out today's UV index (Environment Canada)