Skin cancer is the most common cancer in Canada and the most preventable. It is the fourth most common cancer diagnosed in the 15-34 years age range. For Canadians, weather is a constant topic of conversation although it is more likely to feature snow and cold than heat and sun. Why such an increase in skin cancer? In the 19th century a “tan” was associated with working class labourers who had no choice but work outside. By the 20th century, a sun tan became a symbol of affluence and beauty. Victorian modes of dress were replaced with considerable exposure to the sun. In the 21st century when we should know better we still consider a tan as a status symbol. Tanned skin eventually becomes wrinkled, leathery and unattractive. People are spending significant amounts of money to reverse the signs of ageing caused by the sun. Would prevention not make more sense?

Some Canadians are getting the message and sales of sun block products have increased in recent years. Children and young adults remain the most vulnerable since 60% of UV radiation exposure occurs before the age of 18.Our climate tends to mean that we face concentrated exposure to UV radiation over a shorter period of time. The Canadian Cancer Society estimates that 60%-70% of skin cancer can be prevented by adopting a sensible attitude to “sun worship”. Consider how much better we feel physically and mentally when the sun shines, especially after a long, cold winter. We do need some sunlight to manufacture vitamin D and UV radiation can have a positive effect on skin conditions like acne and psoriasis.

There are three types of UV rays: UVA, UVB and UVC. UVA rays pass through the ozone layer and can penetrate the skin most deeply causing wrinkling, premature ageing and skin cancer. Tanning salon devices can emit up to two to five times more UVA than natural sunlight.UVB rays are mostly absorbed by the ozone layer but those that do reach us are believed to be the main cause of skin burning, tanning and skin cancer. They also harm the immune system.UVC rays are the most dangerous but they do not reach earth’s surface. Most people are aware that the ozone layer is thinning resulting in more UV radiation being able to cause damage. Time spent in the sun is not the only factor to consider.

UV radiation is strongest when the sun is directly overhead, particularly in summer, since it has least distance to travel through the atmosphere. The closer we are to the equator the thinner the ozone layer and the higher the altitude the less UV rays are absorbed. We can still burn on a cloudy day or from sun reflected off water, snow, sand and even concrete. Daily UV index readings allow us to take appropriate precautions when outdoors.

People whose skin has deeper pigmentation are at lower risk. Cosmetics , cosmetic procedures(chemical peels and microdermabrasion) and medications like antibiotics, antidepressants, immunosuppressants, anti-inflammatories and retinoids may cause irritation, redness and increased risk of sunburn..

UV rays damage the DNA in skin cells causing them to die. If cells do not repair themselves they may mutate genetically and these defective cells grow into cancer cells.

Skin damage is cumulative building up with each exposure. There is a misconception that a “base tan” protects against further damage. In fact it offers the equivalent of using an SPF 4 protection product. Everyone should be encouraged to examine moles and freckles on a monthly basis particularly in fair skinned people, or where there is a history of sunburns early in life,a family history, a large number of moles, atypical moles and when skin always burns but never tans.

Non-melanoma skin cancers are the most common and can be treated successfully.

Basal cell carcinoma accounts for 70%-80% of all skin cancers and develops mostly on the face, ears, neck, and forearms. These cancers start as clear or flesh coloured blister-like bumps that eventually form small scaly patches. Growth is slow , rarely spreads to other parts of the body and is most common in people over 40.

Squamous cell carcinoma occurs most commonly on sun exposed skin. It grows more quickly and can spread if not treated promptly. It usually appears as a red, scaly thickened area that may be tender or bleed easily.

Melanoma. This is the least common but most serious form of skin cancer. These can appear anywhere on the body, 50% occurring in people under age 50 and a major cause of death from the disease. The area may be two or more colours with changes in shape, size and surface and may be tender or bleed.

Sunscreens should be applied at least 20 minutes prior to going out into the sun and are not meant to lengthen the time spent in the sun. They should be re-applied frequently especially after swimming or heavy sweating. Use of sunscreens (SPF 30) in young children and up to age 18 can reduce the lifetime incidence of non-melanoma skin cancers by 78%

The Sun Protection Factor (SPF) refers to the ability to block or screen the burning rays.

SPF 15 blocks 93% of UVB rays while SPF 30 and higher block 97%.

Chemical blocks protect by absorbing the UV rays. Physical blocks such as titanium dioxide and zinc oxide create a physical barrier to reflect UV rays.