What is skin cancer?

Skin cancer occurs when the genetic material of skin cells is damaged, allowing them to grow in an uncontrolled way.  One of the most important factors in causing this damage is prolonged exposure to ultraviolet (UV) radiation in the sun's rays, and it is thought that 95 to 99% of skin cancers in Australia are due to this. Over 200,000 Australians are treated for skin cancer each year and more than 1,000 Australians die from it every year.

Skin cancers can be broadly divided into non-melanoma skin cancers (NMSC) and malignant melanoma (MM). The commonest forms of NMSC are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC).

Fair-skinned Australians are at highest risk of developing both NMSC and MM, with exposure to sunlight in childhood and adolescence being a major risk factor.  The risk of MM increases greatly with repeated episodes of sunburn, particularly if they occur before adulthood. Also at risk are people who have fair skin, increased numbers of unusual moles (dysplastic naevi), depressed immune systems, and a family or past history of MM. However, persistent moderate sun exposure over time increases the risks of both NMSC and MM.