Keratinocyte cancer incidence in Australia: a review of population-based incidence trends and estimates of lifetime risk.

OBJECTIVES

To review the most recent population-based estimates of keratinocyte cancer incidence in Australia, to describe the trends over time and to calculate lifetime risk of developing these skin cancers.

METHODS

We conducted a literature search of PubMed/MEDLINE from 2001 to August 2021 to identify relevant literature. We defined eligible articles as those reporting population-based studies of adults and excluded studies that reported only on high-risk or paediatric populations, or on incidence of precursor or related lesions. We summarised identified studies qualitatively. We calculated lifetime risk of developing keratinocyte cancer using the methods of Cancer Research UK, adjusting for multiple primaries and the competing risk of death.

RESULTS

We identified six eligible studies. In the absence of compulsory notifications of keratinocyte cancer to state and territory cancer registries in Australia, all estimates of national incidence rates of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) have limitations. The most recent population-based estimates of people annually affected for the period 2011-2014 (BCC: 770/100 000 person years; SCC: 271/100 000 person years) represent the lower end of the possible range of incidence rates nationally. Because many people are affected by multiple lesions, the lesion-based incidence estimates are more than double the person-based rates (BCC: 1565/100 000 person years; SCC: 580/100 000 person years). Analyses of temporal trends in treatment rates (excisions, cryotherapy/curettage) show increases over time, most marked for people aged 55 years or older. We estimate that 69% of Australians will have at least one excision for histologically confirmed keratinocyte cancer in their lifetime (60% to age 79 years).

CONCLUSION

The available evidence on national incidence rates is out of date and of moderate quality, but indicates very high rates of keratinocyte cancer in Australia. We recommend that population-based cancer registries work towards statutory notification and routine reporting of keratinocyte cancer in Australia.