PATTERNS OF TREATED NONMELANOMA SKIN-CANCER IN QUEENSLAND - THE REGION WITH THE HIGHEST INCIDENCE RATES IN THE WORLD

The incidence of non-melanoma skin cancer, comprising basal cell carcinoma and squamous cell carcinoma, was studied in Queensland during 1984. The world-standardised annual incidence rates (per 100,000 population) for the number of persons with non-melanoma skin cancer were estimated to be 1372 for men and 702 for women, the highest recorded incidence rates in the world. Rates in men were nearly double the rates in women and age-specific incidence rates increased curvilinearly with age. There were, on average, 1.4 skin cancers per person with non-melanoma skin cancer and the ratio of basal cell carcinomas to squamous cell carcinomas was approximately three to one. The age-standardised annual incidence rate (per 100,000 population) of basal cell carcinoma for residents of the Gold Coast was 1.83 times the Brisbane rate for men and 1.57 times that for women, indicating significant differences between the two regions. For squamous cell carcinoma the regional differences were not statistically significant. The average potential number of non-melanoma skin cancers (per person) treated during the lifetime of a cohort of 100,000 was estimated to be 0.014 for men and 0.009 for women by age 40. By age 65, these numbers increased to 0.22 for men and 0.11 for women. At age 90, these average numbers were 1.09 and 0.42, respectively. Although the incidence of non-melanoma skin cancer is much higher in the older age groups, it should be kept in mind that it also affects the younger population; 1028 Queenslanders under 40 required treatment for 2300 non-melanoma skin cancers in 1984. This study which provides baseline information about the occurrence of non-melanoma skin cancer in Queensland emphasises the importance of developing safe sun-exposure habits, detecting non-melanoma skin cancer early and protecting and restoring the atmosphere.