The incidence of non-melanocytic skin cancers in an Australian population: results of a five-year prospective study.

Two thousand, six hundred and sixty-nine persons who were aged 40 years and older attended for examination of the light-exposed areas of the head and neck, forearms and dorsa of the hands during a skin-cancer survey of the population of Maryborough, which was conducted annually for five years from 1982-1986 inclusive. Sixty (2.25%) persons--12 persons each with a squamous-cell carcinoma and 48 persons with a total of 51 basal-cell carcinomas--had at least one non-melanocytic skin cancer at the first examination. One thousand, nine hundred and eighty-one (74% of the study population) persons were seen on more than one occasion, which allowed for 6288 person-years of follow-up for the determination of the incidence of new cancers. The findings showed a calculated minimal age-standardized incidence rate of 873 non-melanocytic skin cancers/100,000 population each year. The minimal incidence rate for basal-cell carcinomas was 672 cases/100,000 population each year and for squamous-cell carcinomas was 201 cases/100,000 population each year. The rate ratio of the incidence of basal-cell carcinomas to that of squamous-cell carcinomas was 3.34 to one. Age, sex, skin reaction to sunlight and occupation all were significant factors in the determination of the risk of developing non-melanocytic skin cancers. The enormous costs that are involved in the treatment of non-melanocytic skin cancers and related lesions suggest that more time, effort and money need to be spent to reduce what has become a major public-health problem in Australia.