May is Skin Cancer Awareness Month!

Skin Cancer Awareness

Skin cancer is the most common malignancy in South Africa. There are two main categories of skin cancer – melanoma and non-melanoma. Non-melanoma skin cancers comprise basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Melanoma occurs less frequently, but is more aggressive and associated with a poor outcome if diagnosed late.

Most skin cancers are caused by an interplay between genetic and environmental risk factors. In contrast to genetic risk factors which are non-modifiable, environmental risk factors are potentially modifiable and provide an opportunity for intervention.

Genetic risk factors:

  • Fair skin.
  • Tendency to burn, inability to tan.
  • Red hair colour.
  • Family history of melanoma.
  • Multiple moles or freckles.

Environmental (modifiable) risk factors:

  • Intense intermittent sun exposure.
  • Chronic sun exposure.
  • Tanning bed use, especially under the age of 35 years.


An awareness of the signs of skin cancer can help ensure early detection in at risk individuals. Included below is a brief description of the clinical presentations of the three most common types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma.

Basal cell carcinoma (BCC):

BCCs can appear almost anywhere on the body. They are often elevated and translucent nodules that may form a crust or ulcer centrally.

Squamous cell carcinoma (SCC):

SCCs appear most commonly on sun exposed areas of the body such as the face, forearms and scalp. They are usually raised, pink or red nodules or patches that may crust or ulcerate.


Malignant melanoma can occur in pre-existing moles or arise on previously normal skin. The ABCDE rule can be used:

  • Asymmetry – a mole with one half unlike the other
  • Border – scalloped or poorly defined edges
  • Colour- variations and inconsistency, tan, brown, black, red, white and blue
  • Diameter – larger than 6 mm or has grown in size
  • Evolving – change in the size, shape, colour or appearance of a mole, or is growing in an area of previously normal skin


If you notice any of these warning signs during regular skin self-examination be sure to report them to your doctor or dermatologist promptly or contact Dr. Johann de Wet at 021 111 0460 or The early detection of skin cancer is key in ensuring a good outcome.