Trends in non-melanocytic skin cancer treated in Australia: the second national survey.

An Australia-wide survey in 1985 recorded the highest rates of medically treated non-melanocytic skin cancer (NMSC) ever reported. We report the findings of a repeat survey conducted in 1990. This second survey confirmed the differences, by age, sex, body site, latitude, country of birth and skin reaction to strong sunlight, that were observed in 1985. Over the 5-year period certain changes were noted: the incidence of NMSCs increased by 19%, of basal-cell carcinomas (BCC) by 11% and of squamous-cell carcinomas (SCC) by 51%. With advancing age, men and women differed in their incidence, and this difference was greater for SCC than for BCC. Log-linear modelling, however, failed to detect either a cohort or a survey effect between the 2 surveys. The proportional distribution of BCCs and SCCs by body site indicated an increase in BCCs on the trunk in both men and women, and half the proportion of SCCs on the head and neck in women as compared with men. The latitudinal gradients observed in 1985 were even stronger in 1990; the population living north of 37 degrees S experienced a 30% increase in the incidence of treated NMSC between 1985 and 1990, while the population living south of 37 degrees S had a 25% decrease. The implications of these findings for cancer-control initiatives are discussed.