Clear, sunny, summer days can boost our spirits. On the downside, too much sun can lead to skin cancer. We all need to think about it because nearly half of all North Americans who live to age 65 will develop skin cancer at least once.
Skin cancer begins in the epidermis – the thin layers of cells that provide a protective cover for your body. The epidermis is formed by: squamous cells, which lie just below the outer surface and function as the skin’s inner lining; basal cells, which sit beneath the squamous cells and produce new skin cells; and melanocytes, which are located in the lower layer of your epidermis and produce melanin – the pigment that gives skin its colour.
Skin cancer types are determined by where in the epidermis they originate. Basal cell is the most common, but least dangerous form of skin cancer. Squamous cell is less common, but since it is more likely to spread, it is still dangerous.
Melanoma is the least common, but most aggressive, and most likely to spread. If untreated, melanoma will likely become fatal.
Since most skin cancers are caused by excessive exposure (particularly childhood exposure) to ultraviolet rays, skin cancer usually develops on areas of sun-exposed skin, such as the scalp, face, lips, ears, neck, chest, arms and hands, and legs. However, skin cancers may also occur on palms, beneath fingernails or toenails, and even the genital area.
Skin cancer affects people of all skin tones, even those with darker complexions. Even so, the following factors may increase your risk.
You live in a sunny, warm climate, so you have a longer season of sun exposure.
You live at a high altitude, so the sun’s radiation is stronger. You spend a considerable amount of time exposed to the sun without sunscreen or shading. You use a tanning bed or lamp.
You have fair skin with less melanin; thus, less protection from the sun’s damaging rays. You have blonde/red hair, light coloured eyes, and sun-sensitive, freckled skin.
You had one or more blistering sunburns as a child or teenager. Each sunburn increases your risk factor exponentially – even adult sunburns.
You have many moles, or irregularly shaped moles (dysplastic nevi). You have skin lesions (actinic keratoses) – precancerous skin growths that look like rough, scaly patches ranging in colour from brown to dark pink. They are often found on the head, face and hands of fair-haired people who have had past sunburns.
Your family has a history of skin cancer, especially if a parent or sibling has been affected. You smoke. You’ve had skin cancer before.
You have a weakened immune system or are taking immunosuppressant drugs following an organ transplant. You have been exposed to radiation for the treatment of skin conditions such as eczema or acne. You have been exposed to arsenic.
To prevent skin cancer from metastasizing (breaking away and travelling) to other parts of your body, it is important to identify it as early as possible. Here is what to look for.
Squamous cell carcinoma can appear as a flat, red, scaly, thickened crusty patch on sun-exposed skin. Or, if may appear as firm, hard nodules that stick out from the skin like small domes surrounded by inflammation and occasionally bleed. They appear to originate in a hair follicle. Although initially quite small, if left untreated, these nodules may develop into a large mass.
Basal cell carcinoma usually appears on the shoulders, head, or neck as a raised, smooth, pearly bump. Sometimes small blood vessels can be seen within these tumors because their outer layer of skin becomes transparent. Since the centre of this type of tumor frequently becomes crusty and then bleeds, many mistakenly believe the tumor is just slow-healing sore. This form of skin cancer is the least deadly; with proper treatment it can usually be completely eliminated.
Malignant melanoma comes in many colours – shades of brown, black and even pink. The pink tumors (amelanotic melanoma) tend to be the most aggressive. These are the warning signs for melanoma.
A mole changes in shape, size, colour or height, and/or if it becomes itchy, ulcerated, red, inflamed or bleeding.
When examining a mole, consider the mole “ABCDE” cancer warning signs: A: Asymmetrical; B: Borders (indistinct); C: Colour (variegated); D: Diameter (6 mm+); and, E: Evolving (changing shape, size and colour).
Avoid skin cancer.
Stay in the shade between 10 a.m. and 4 p.m. Wear a wide-brimmed hat. Avoid tanning booths. When outdoors, use a broad spectrum sunscreen; reapply every two hours, or immediately after swimming or sweating.
Examine your skin regularly. Early detection is vital.
If you notice any of the above signs, see your doctor now. Early detection and treatment is the best way to increase your chances of a good outcome.