In 1980, in Australia, public health campaigns aimed at reducing the incidence of skin cancer were started. These campaigns have been hailed as a success in reducing the incidence of invasive melanoma in young Australians [1]. However, the epidemiologists making these claims failed to take into account the change in the racial composition of the Australian population. If these changes were taken into account, data up to 2009 showed that the incidence of melanoma had increased in the susceptible population under the age of 30 years [2]. These people had been raised while the public health campaigns have been running suggesting that the campaigns had been ineffective. Data on melanoma and the Australian population are now available up to 2016, and are presented in this article.
The materials and methods used in this article have been described before [2]. Data from the Australian Bureau of statistics was used to determine the number of people, aged under 40 years, at low risk for melanoma. These were people born in Asia, the Middle East, the Pacific Islands, sub-Saharan Africa, their Australian born children, Aborigines, and Maoris [3]. Australian pathologists are required by law to notify the State Cancer Registries and cases of invasive melanoma have been registered since 1982 [4].
The results are summarized in the table 1. In the 34 years that data are available the total population under the age of 40 years increased by 33.7%. However, the susceptible population only decreased by 1.4%. The number of people who had a melanoma removed increased by 22.9%, from 1,011 to 1,243. For the entire population, the crude rate (CR) of melanoma decreased from 10.4 to 9.6 per 100,000, a 7.7% decrease. However, the CR for the susceptible population increased by 25.5%, from 11.0 to 13.8 per 100,000.
The data highlight the importance of determining the number of susceptible people when calculating the incidence of a disease, such as melanoma, where susceptibility varies greatly according to race. Australia, like many Western countries, has welcomed hundreds of thousands of young immigrants at low risk for melanoma. Australia, like other Western countries, is reporting that the incidence of melanoma is decreasing in young people [5]. If adjustments to the data, to account for increases in people at low risk for melanoma, the claims that melanoma is decreasing in young cohorts may not be valid, just as these claims are invalid in Australia.
Table 1. Invasive melanomas removed from Australians under 40 years of age
* Crude rate per 100,000 susceptible people
- Whiteman DC, Green AC, Olsen CM (2016) The growing burden of invasive melanoma: projections of incidence rates and numbers of new cases in six susceptible populations through 2031. J Invest Dermatol 136: 1161e71. [Crossref]
- Czarnecki D (2014) The Incidence of Melanoma is Increasing in the Susceptible Young Australian Population. Acta Derm Venereol 94: 539-541.
- www.abs.gov.au
- http://www.aihw.gov.au/cancer
- Karlsson PM, Fredrikson M (2007) Cutaneous malignant melanoma in children and adolescents in Sweden, 1993–2002: The increasing trend is broken. Int J Cancer 121: 323–328. [Crossref]