Incidence and determinants of skin cancer in a high-risk Australian population

In a Queensland community, we surveyed the incidence of basal-cell carcinoma (BCC) and squamous-cell carcinoma (SCC), and associated risk factors. In December, 1986, 2,095 residents were examined by dermatologists for skin cancer. Of these, 1,770 further participated in a follow-up postal survey in December, 1987, regarding all skin cancers in the preceding 2 years, and 87 reported being treated for skin cancer in the 2-year period between December 1985 and November 1987. The estimated annual incidence rates of non-melanoma skin cancer in men and women aged 20-69 years were 2,389/100,000 and 1,908/100,000 respectively, with an overall ratio of BCC cases to SCC cases of 4.5 to one. While both tumour types occurred more commonly in fair-complexioned people, the risk associated with high sun exposure was greater for SCC than for BCC. Clinical signs of solar skin damage, especially the number of solar keratoses on the face, were the strongest predictors of both types of skin cancer.