Occurrence of melanoma

  • Image, occurrence of skin cancer.

    New Zealand and Australia have the world’s highest rates of melanoma, the most serious type of skin cancer. Melanoma is mainly caused by exposure to ultraviolet (UV) light, usually from the sun. New Zealand has naturally high UV levels, especially during summer.

    The risk of developing melanoma is affected by factors such as skin colour and type, family history, and the amount of sun exposure. Melanoma can affect people at any age, but the chance of developing a melanoma increases with age. We report on age-standardised rates of melanoma to account for the increasing proportion of older people in our population.

    We classified Occurrence of skin cancer as supporting information.

    Key findings

    No trend could be determined at the 95 percent confidence level for the total age standardised rate of melanoma (per 100,000 population) between 1996 and 2013.

    • From 1996 to 2013, the age-standardised rate of melanoma for males showed an increasing trend at the 95 percent confidence level. No trend could be determined at the 95 percent confidence level for females.
    • The age-standardised rate of melanoma is higher for males than for females. For example, in 2015 the provisional rate for males was 40.5, while that for females was 30.9.
    • Melanoma affects more older people than younger people. In 2015 the provisional rate for people aged:
      • 75 years or older was 244.5
      • 65–74 was 167.8
      • 45–64 was 71.6
      • 25–44 was 17.8
      • 0–24 was 1.1.
    • From 1996 to 2013, melanoma rates showed different trends for different age groups in the total population. At the 95 percent confidence level:
      • registrations of people aged 60 and older increased
      • registrations of people aged 15–34 and 40–44 decreased
      • no trend could be determined for registrations of people aged 14 and under, 35–39, and 45–59.
    Figure 1

    Graph, Total registrations and age-standardised rates of melanoma occurrence, 1996–2015.

    Note: 2014–15 data are provisional and subject to change.
    Figure 2
    Note: 2014–2015 data are provisional and subject to change.
    Figure 3
    Note: 2014–2015 data are provisional and subject to change.
    Figure 4
    Note: 2014–2015 data are provisional and subject to change.
    Table 1
    Age group Total population Males Females
    4 Image, Indeterminate trend. Image, Indeterminate trend. Image, Indeterminate trend.
    5–9 Image, Indeterminate trend. Image, Indeterminate trend. Image, Indeterminate trend.
    10–14 Image, Indeterminate trend. Image, Indeterminate trend. Image, Indeterminate trend.
    15–19 Image, Decreasing trend, improving state. Image, Indeterminate trend. Image, Decreasing trend, improving state.
    20–24 Image, Decreasing trend, improving state. Image, Decreasing trend, improving state. Image, Decreasing trend, improving state.
    25–29 Image, Decreasing trend, improving state. Image, Decreasing trend, improving state. Image, Decreasing trend, improving state.
    30–34 Image, Decreasing trend, improving state. Image, Decreasing trend, improving state. Image, Indeterminate trend.
    35–39 Image, Indeterminate trend. Image, Indeterminate trend. Image, Indeterminate trend.
    40–44 Image, Decreasing trend, improving state. Image, Indeterminate trend. Image, Indeterminate trend.
    45–49 Image, Indeterminate trend. Image, Indeterminate trend. Image, Decreasing trend, improving state.
    50–54 Image, Indeterminate trend. Image, Indeterminate trend. Image, Indeterminate trend.
    55–59 Image, Indeterminate trend. Image, Indeterminate trend. Image, Indeterminate trend.
    60–64 Image, Increasing trend, declining state. Image, Increasing trend, declining state. Image, Increasing trend, declining state.
    65–69 Image, Increasing trend, declining state. Image, Increasing trend, declining state. Image, Increasing trend, declining state.
    70–74 Image, Increasing trend, declining state. Image, Increasing trend, declining state. Image, Increasing trend, declining state.
    75+ Image, Increasing trend, declining state. Image, Increasing trend, declining state. Image, Increasing trend, declining state.
    Note: All trends are assessed at the 95 percent confidence level. Image, Increasing trend, declining state.  An upward arrow indicates an increasing trend. Image, Decreasing trend, improving state.  A downward arrow indicates a decreasing trend. Image, Indeterminate trend.  A tilde indicates an indeterminate trend.
    Source: Ministry of Health

    Definition and methodology

    New Zealand and Australia have the world’s highest rates of melanoma (Ferlay et al, 2015; Ministry of Health, 2016), the most serious type of skin cancer.

    Our data on melanoma registrations come from the New Zealand Cancer Registry and the Ministry of Health's Mortality Collection. The passing of the Cancer Registry Act 1993 and Cancer Registry Regulations 1994 led to significant improvements in data quality and coverage (Ministry of Health, 2013). A sharp increase in registrations after 1993 is likely to have been related to these legislative and regulatory changes; for this reason we have only analysed data from 1996.

    We report on age-standardised rates per 100,000 population, where our population profile is standardised to the World Health Organization’s world standard population. Using age-standardised rates allows comparisons to be made between different datasets or years. This means any differences in rates over time will be due to factors other than changes in the age structure of the population. Melanoma, and cancer in general, is a disease that mainly affects older people. Because our population is ageing, we can expect an increase in our cancer rates.

    Increases in melanoma rates may be due to several factors, including more people seeking diagnosis of unusual skin conditions because they have greater awareness of the risks and repercussions of melanoma. Some people are more at risk of developing melanoma than others; for example, those with fair skin (Ministry of Health, 2016). Darker skin produces more melanin, a protein that protects the skin from harmful UV radiation.

    In addition to a variety of behavioural reasons (Geller et al, 2006), there are genetic reasons that melanoma incidences are higher in men (Dunford et al, 2017).

    Data quality

    We classified Occurrence of skin cancer as supporting information.

    Relevance

       This supporting information is an indirect measure of the ‘Impacts on public health' topic.

    Accuracy

      The accuracy of the data source is of high quality. 

    See Data quality information for more detail.

    References

    Dunford, A, Weinstock, DM, Savova, V, Schumacher, SE, Cleary, JP, Yoda, A,… Lane, AA (2017). Tumor-suppressor genes that escape from X-inactivation contribute to cancer sex bias. Nature Genetics, 49(1), 10–16.

    Ferlay, J, Soerjomataram, I, Dikshit, R, Eser, S, Mathers, C, Rebelo, M, … Bray, F (2015). Cancer incidence and mortality worldwide: Sources, methods and major patterns in GLOBOCAN 2012. International Journal of Cancer, 136(5), E359–E386. http://doi.org/10.1002/ijc.29210.

    Geller, AC, Miller, DR, Swetter, SM, Demierre, M, Gilchrest, BA (2006). A call for the development and implementation of a targeted national melanoma screening program. Archives of Dermatology, 142(4),504–507.

    Ministry of Health (2013). New Zealand Cancer Registry – technical details. Retrieved from www.health.govt.nz.

    Ministry of Health (2016). Melanoma. Retrieved from www.health.govt.nz.

    Archived pages

    See Occurrence of skin cancer (archived October 2017).

    Updated 19 October 2017

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