Dr Johann de Wet – Advanced Vergelegen Surgical Centre
Skin cancer is the most common cancer worldwide. It is typically divided into melanoma and non-melanoma skin cancer. Non-melanoma skin cancer encompasses basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) and is by far the most common cancer in South Africa. Although melanoma is less common it is more dangerous as it is much more likely to spread (metastasise). The rates of skin cancer are increasing globally, and South Africa is no exception.
The common risk factor for all skin cancers is UV light exposure, whether this comes from natural sunlight or artificial sources like tanning beds. Both accumulated sunlight exposure and bursts of intense sunlight exposure are considered risk factors.
The South African population is at a particularly high risk of skin cancer due to the country’s geographical position and level of ultraviolet radiation (UVR). South Africans are also known to love the outdoors and as a result may have increased sun exposure due to outdoor occupational and recreational activities.
Other risk factors for developing skin cancer include:
- Skin that burns quickly or is prone to freckling.
- A lighter natural skin tone.
- Blond or red hair, with blue or green eyes.
- A large number or specific types of moles.
- A personal or family history of skin cancer.
- A weakened immune system (those with HIV, for example).
- Older age.
What is the appearance of skin cancer?
BCCs can take on different forms, as many types exist. Sometimes it can look like a small pearly lump with visible blood vessels on the surface, or like a red, scaly patch. BCCs may even develop into ulcers.
SCCs tend to start off as scaly, red patches that may also become ulcers or bleed. It often looks quite inflamed or develop a crusty appearance. It can also present as a non-healing scab covered wound.
A melanoma usually looks like a dark mole that starts to change its appearance or that looks unusual compared to its neighbours. It is important to know that melanoma can development in existing moles but also in areas where no previous moles existed. Melanomas can be recognised by the ABCDE rule:
Diameter greater than 6 millimetres
In rare instances, a melanoma can look pink, red or pale. It is important to note that black South Africans are disproportionately affected by melanomas at ‘acral’ sites – often the sole of the foot.
Dermatologists are trained to manage skin cancers, being the only specialists with years of training in the recognition and treatment of these cancers. Dermatologists are able to detect skin cancers at an early stage using sophisticated techniques such as dermoscopy and mole mapping. A partial or complete biopsy may be taken if a skin growth is suspicious.
Skin cancers may reach a considerably large size or spread to other sites of the body if they are not detected early enough. Fortunately, this can be prevented by frequently examining your skin for changes at home, combined with a Total Body Skin Examination (TBSE) performed by your dermatologist at regular intervals.
Being sun smart
- Seek shade when appropriate, remembering that the sun’s rays are strongest between 10 a.m. and 2 p.m.
- Wear sun-protective clothing, a wide-brimmed hat and sunglasses with UV protection, when possible.
- Apply a broad-spectrum, water-resistant sunscreen with an SPF of 30 or higher. Broad-spectrum sunscreen provides protection from both UVA and UVB rays.
- Use sunscreen whenever you are going to be outside, even on cloudy days.
- Apply enough sunscreen to cover all skin not covered by clothing. Most adults need about 1 ounce — or enough to fill a shot glass — to fully cover their body.
- Don’t forget to apply to the tops of your feet, your neck, your ears and the top of your head.
- When outdoors, reapply sunscreen every two hours, or after swimming or sweating.
- Use extra caution near water, snow and sand, as they reflect the damaging rays of the sun, which can increase your chance of sunburn.
- Avoid tanning beds. Ultraviolet light from tanning beds can cause skin cancer and premature skin aging.
- Consider using a self-tanning product if you want to look tan, but continue to use sunscreen with it.
- Perform regular skin self-exams to detect skin cancer early, when it’s most treatable, and see a board-certified dermatologist if you notice new or suspicious spots on your skin, or anything changing, itching or bleeding.
Sunscreen is a topical cream which can be applied to reduce amount of solar ultraviolet radiation (UVR) that the skin absorbs. Although it is important to remember that sunscreen is not a substitute for sun avoidance or sun protection!
Sun avoidance should be practiced during the danger hours of 10am to 4pm as per WHO guidelines. If it is not possible to avoid sun exposure you should practice sun protection by wearing a hat, sun protective clothing with ultraviolet radiation protection, sunglasses with UV protection and finding shade under an umbrella or tree.
Types of sunscreen
Physical sunscreen: Also called mineral sunscreen or sunblock. Options in this category include zinc oxide and titanium dioxide which are inorganic minerals. These minerals physically absorb and reflect the UV rays from the skin and therefore avoid absorption and resultant sunburn. This is a very good option and safe option for children as there is less chance of skin irritation. Physical sunscreens can leave a white residue on the skin which can be cosmetically unacceptable for some.
Chemical sunscreen: Absorb UV rays before it can damage the skin and are soluble organic compounds. Chemical sunscreens usually do not leave a white residue on the skin.
What is SPF and how to choose the right sunscreen?
Sun protection factor (or SPF) gives you an indication of how long the sun’s UVB rays would take to redden your skin if you apply the sunscreen compared to not applying sunscreen. Therefore, if you use a SPF30 product as directed, it would take you 30 minutes longer to burn compared wearing no sunscreen.
If you spend most days indoors, you can use a sunscreen with a SPF of 15 or higher. If you spend a lot of time outdoors, you will need a SPF30 or higher with water-resistance. Make sure to choose a broad-spectrum sun screen with UVA and UVB filters to make sure that you get the best coverage to avoid sun damage.
How to apply sunscreen
Apply sunscreen daily 30 minutes before you leave the house in the mornings. Remember areas such as the tops of your ears, back of your neck, exposed scalp, tops of feet and behind the knees as these are easy to miss.
You should use about 1 shot glass of sunscreen to cover the whole body. Most people use small amounts of sunscreen which results in reduced efficacy and possibly results in sunburn.
To remain protected when outdoors, reapply sunscreen every two hours, or immediately after swimming or sweating.
Benefits of sunscreen
Reduces your risk of skin cancer e.g. squamous cell carcinoma and melanoma
Reduces your risk of precancerous lesions e.g. actinic keratosis
Prevents photoaging due to sun damage
Certain medications or skin conditions such as lupus or atopic dermatitis worsen with sun exposure and sunscreen can assist with reducing symptoms.