Skin cancer

What is skin cancer?

Skin cancer is one of the most common types of cancer. Sun radiation is a major risk factor for the development of skin cancer. It can affect people at any age, but is more common among the elderly and rarely seen in children. The cancer causes changes in skin texture or colour that can usually be seen with the naked eye. If treated early, 90% of skin cancers can be cured.

What are the different types of skin cancer?

There are two main types of skin cancer — non-melanoma (basal cell and squamous cell carcinoma) and malignant melanoma (cancer in moles):

Basal cell carcinoma

Basal cell carcinoma is a common form of skin cancer that begins in the outer layer of the skin (the basal cell layer of the epidermis) and develops slowly, causing a lump or a small, painless ulcer, often on the face or neck. It usually occurs in middle-aged and older people or in those whose work involves prolonged exposure to the sun. If treated early, the cure rates are high.

Squamous cell carcinoma

Squamous cell carcinoma is not as common as basal cell carcinoma but also results from excessive sun exposure as well as pipe and cigar smoking. It develops as a small, often painless, skin ulcer, and can affect any part of the body but is most common on the mouth and lip. Although not one of the more dangerous cancers, it can spread to other parts of the body if not treated promptly.


Malignant melanoma is a very dangerous type of cancer that begins in the layer of the skin that tans (pigmentation-system), usually developing from an existing mole on the back, shoulders or the back of the legs. In rare cases, the tumour may begin in the eyes, the respiratory passage, the intestine or the brain. Although not as common as basal cell and squamous cell carcinoma, it is more dangerous, and early discovery and treatment are vital.

What causes skin cancer?

Exposure to ultraviolet light (sunlight or tanning beds) is the most common cause of skin cancer, although hereditary factors may also increase an individual’s risk of developing the disease.

What are the symptoms of skin cancer?

Basal cell carcinoma

  • Small lumps or scar-like changes on the skin which do not heal.
  • Small, often painless, sore with raised borders (ulcer) on the skin.
  • A sore that will not heal or develops into a tumour.

Squamous cell carcinoma

  • Patch of scaly eczema.
  • A sore that will not heal or that develops into a tumour.


  • An existing mole which begins to change colour, increase in size or bleed.
  • The mole may itch, with sores or reddening in the surrounding area.
  • A new mole develops with ragged edges and uneven colours, varying from brown or black to blue or orange.

How is skin cancer diagnosed?

Your doctor will examine your skin and look for signs indicating that the cancer has spread to the surrounding tissue or lymph nodes. You will be asked whether you have noticed any changes in the appearance of your skin. A biopsy (removal of a small piece of tissue for microscopic analysis) is usually performed to definitively diagnose skin cancer.

How is skin cancer treated?

Basal cell carcinoma

The tumour is usually removed surgically, exposed to heat and scraped off or exposed to radiation.

Squamous cell carcinoma

The tumour is usually removed surgically or radiation therapy may be used.


The standard treatment is to remove the tumour and some of the normal skin around it and the fatty tissue beneath it.

What can I do?

  • Avoid excessive exposure to sunlight — wear clothing and hats to cover you, and avoid midday sun.
  • Use sunscreen lotions when you must be outdoors, but remember that sunscreens only protect the skin from getting burned, they do not block out the rays that cause skin cancer.
  • Sunburn increases the risk of developing skin cancer so, if you have children, protect them from sunburn until age 16. Although the sunburn will clear up the skin may have suffered damage that will become apparent later in life.
  • Consult your doctor if you have sores that will not heal or notice any strange changes in your skin.

What is the outlook?

It is important that skin cancer is detected and treated as early as possible. If treated early, most skin cancers can be cured; if untreated, the cancer can spread to other parts of your body. Skin cancer can recur, so it is important that you examine your skin regularly for any changes and see your doctor for a check-up every six to 12 months.

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