Keratinocyte cancers in South Australia: incidence, geographical variability and service trends.

Objectives: To determine the incidence, multiplicity, geographical variability and service trends of keratinocyte cancers (KC) in South Australia (SA).

Methods: Medicare Australia data with a unique identifier were used to assess the number of people treated over years 2010-2014. A maximum of one KC service claim per year was used to determine incidence. Age-standardised rates were estimated as were KC service activity trends.

Results: There were 497,581 services to 204,183 SA residents for KC, solar keratoses, locally aggressive skin tumours or suspicious skin lesions. Of these, n=159,137 services were for KC (77,502 people). The five-year (2010-2014) age-standardised rate of KC in SA was 1,466.6 (95%CI 1,458.3-1,474.8) per 100,000. Forty per cent of people had more than one KC removed. Men accounted for more incident cases (59.2%). Age-specific rates showed least variability over time in the youngest age group (15-44 years). For 26 geographical areas, higher age-standardised ratios of KC were seen in coastal and agricultural areas. There was a 59% increase in services for KC from 2000 to 2015.

Conclusions: Age-standardised rates for KC are relatively stable in SA, but regional variations are evident. Services for KC continue to rise. Implications for public health: This is the first systematic report of KC in SA. We demonstrate the utility of using validated Medicare data for assessing KC incidence and trends.