Abstract

Non-melanoma skin cancers (NMSC) are the commonest cancers in Australia. Their incidence rate is more than three times the rate of all other cancers combined. The incidence rate continues to rise to a stage where they now affect at least 1% of the population annually, necessitating treatment of more than 150,000 people per year. Exposure to sunlight in susceptible people appears to be the major environmental carcinogen in causation of these tumours. The exact nature of sunlight exposure necessary to induce them is still not entirely clear. Childhood exposure to sunlight stands out as being the major contributor to the development of all the common skin cancers. Solar keratoses are risk factors for NMSC and are precursors of squamous cell carcinoma. They appear to be more sensitive measures of carcinogenic sunlight exposure than frank invasive tumours. They are labile, and fluctuate in appearance clinically over time. Regular use of sunscreen can prevent new solar keratoses and increase clinical remission in existing ones. This is early evidence of the value of regular and adequate photoprotection in the long-term reduction of NMSC in Australia.