Melanoma is the skin cancer that most dermatologists are constantly on the prowl for. If detected and treated early, it can have a >90% cure rate. If left unnoticed or untreated, it can become invasive, eventually reaching the bloodstream and lymphatics and spreading throughout the body. It is the most dangerous skin cancer in the world of dermatology. Melanoma is the 7th most common form of cancer in Canada and the incidence is constantly on the rise. This lethal cancer affected 7800 Canadians in 2019 and killed 1300 Canadians that same year. The lifetime risk of developing melanoma for Canadian women is 1 in 73 and for men is 1 in 59.
So what causes melanoma? Your genetics play a major role in susceptibility and development of the various forms of melanoma. 90% of melanomas are associated with extensive UV exposure both from sun exposure and tanning bed sources. Numerous sunburns, particularly in childhood appear to be a main contributing factor.
Risk factors for melanoma include:
- Fair skin types that burn easily and do not tan but are prone to freckling
- Having > 50 moles (nevi)
- Having numerous moles that are large or unusually shaped (Atypical moles)
- A Family history or personal history of melanoma
- Excessive exposure to UV radiation both as sun exposure and from tanning beds
- History of repetitive sunburns
Melanoma is a tumor that grows from melanocytes, or pigment-producing cells.
These often appear as irregular dark spots on the skin surface that grow and change shape, size and color. Melanomas are most commonly found on the legs in women and on the back in men. 53% of melanomas are found by patients and another 17% by their family members.
The Melanoma Network of Canada describes the ABCDE signs to look for when checking your skin, and when to seek care from a dermatologist.
Asymmetry — the shape of one half of a mole on the skin doesn’t match the other.
Border — edges are normally smooth ovals or circles, not jagged or irregular.
Colour — instead of a uniform brown, black or tan, a mix of brown, salmon colour, white and black is something to be concerned about.
Diameter — watch for a mole over 6 mm or ¼ inch in diameter or changes in size.
Evolution — changes in size, shape, colour, surface or appearance are especially important to watch.
The good news is, that if detected and treated early, the outcome can be excellent. And further, skin cancer such as melanoma is largely preventable. We know there is a direct relationship from UV exposure from the sun, and the development of skin cancer.
- Stay out of the direct sun at the peak of the day between 10:00 and 2:00.
- Wear a hat with a broad brim that covers your ears and neck.
- Choose sun protective clothing with a UPF rating.
- Find yourself a sunscreen that you love and wear it every day. Look for Broad Spectrum on the label and aim for an SPF greater than 30.
- Reapply every 2 hours.
Most importantly, see your dermatologist if you have a new changing spot you are concerned about.