All you need to know about skin cancer

There’s no such thing as a “healthy tan”. Any kind of tan is a sign of sun damage and can ultimately result in you developing skin cancer. Here’s what you need to know about this disease and how to prevent it.

As much as South Africans love being outdoors, it’s important to be aware that sun exposure is contributing to a higher incidence of skin cancer in this country. In fact, melanoma, the deadliest form of skin cancer, now ranks as the fifth most common cancer among men, and the sixth most common among women, according to the National Cancer Registry.

Why is skin cancer incidence so high?

South Africa’s increasing incidence of skin cancer may be a result of our high ultraviolet radiation combined with a general rise in temperatures over recent years. “People who have fair skin and eyes are at an even greater risk, as are those who have experienced severe sunburn, or have many moles. A family history is an additional risk factor, along with a weak immune system,” says Dr Jeremy O’Kennedy, a dermatologist at Mediclinic Sandton. 

Does having dark skin protect you against skin cancer?

According to CANSA, the incidence of malignant melanoma is 15 times less among dark-skinned individuals than among those with light skins. In light-skinned people more than 90% of melanomas occur in sun-exposed skin, whereas in dark-skinned people melanomas tend to appear under the nails or on the soles of feet. CANSA reports that 70% of melanomas in dark-skinned people are found on the lower limb and 90% of melanomas on the leg occur below the ankle.

However, melanoma is only one of several different kinds of skin cancer, Dr O’Kennedy says.

Types of skin cancer

Basal cell carcinoma (BCC). The most common type, BCC may present in several forms: as a pinkish patch of skin, a round growth, or a pearly bump – usually on areas that are frequently exposed to the sun, like the head, neck and arms. 

Squamous cell carcinoma (SCC). This is the second-most common skin cancer and develops out of scaly, dry patches called actinic keratoses. These are precancerous growths, which also develop because of sun exposure. Treating the growths early on may prevent them from progressing to become squamous cell carcinoma, which also resembles a scaly patch. However, it may take the form of a red, hard bump on the skin or a sore that doesn’t heal.

Melanomas. These usually grow out of an existing mole on your body, or present as a new one. Look out, too, for dark patches or skin that suddenly changes appearance. Although melanoma is less common than the nonmelanoma cancers BCC and SCC, it is more likely to become invasive.

It is vital to treat these cancers early on because, left to develop, they can spread to other body parts, often growing deep into the tissues.

Screening for skin cancer

Your dermatologist can screen your skin for changes. This is usually done once a year, depending on your risk profile. However, it’s important to self-check your moles regularly for changes in appearance. Some warning signs are:

• asymmetrical and irregular borders
• variations in colour
• size – a mole that is larger than a pencil eraser should be investigated
• Itching
• bleeding
• changes in size, shape and colour.

Treatment

Localised skin cancer may be treated by removing the lesion, either with a simple excision; curettage and electrodessication (scraping the area with an instrument called a curette before treating it to remove any cancer cells); Mohs micrographic surgery (removing thin layers of cancerous skin); topical chemotherapy; or cryosurgery (freezing the tissue so that it dies).

Prevention

It’s impossible to avoid the sun completely, but strict precautions may help mitigate the risk of skin cancer. Try to stay indoors or seek shade during the hottest part of the day (11am-3pm) and always wear a high-SPF sunscreen (at least SPF50).

To find a dermatologist near you, click here.