What is Skin Cancer?
Skin cancer — the abnormal growth of skin cells — most often develops on skin exposed to the sun. But this common form of cancer can also occur on areas of your skin not ordinarily exposed to sunlight. There are three major types of skin cancer — basal cell carcinoma, squamous cell carcinoma and melanoma.
Most aggressive Skin Cancer is melanoma (cutaneous melanoma)
A type of skin cancer in which the pigment-producing cells of the skin (melanocytes) become cancerous. It usually occurs on the parts of the body that have been overexposed to the sun, but not always. Australia and New Zealand have the world’s highest incidence of melanoma and melanoma is the third most common cancer diagnosed in Australia. The risk of being diagnosed with melanoma by age 85 is 1 in 13 for men compared to 1 in 21 for women.
What is the main cause of Skin Cancer?
Most skin cancers are caused by too much exposure to ultraviolet (UV) rays. To lower your risk of getting skin cancer, you can protect your skin from UV rays from the sun and from artificial sources like tanning beds and sunlamps.
What are signs of Skin Cancer?
Rough or scaly red patches, which might crust or bleed. Raised growths or lumps, sometimes with a lower area in the centre. Open sores (that may have oozing or crusted areas) and which don't heal or heal and then come back. Wart-like growths.
Melanoma Stage
Cancer staging is the process of determining the amount of spread or progression of a cancer from its original site. It is one of the factors used to determine how best to treat the disease. In melanoma, there are five stages: *
STAGE
0
The cancer is confined to the epidermis and has not spread. This is also known as melanoma in situ.
STAGE
1
The tumour is no more than 2mm thick and might or might not be ulcerated. It has not spread.
STAGE
2
The tumour is more than 1mm thick and may be thicker than 4mm. It might or might not be ulcerated. It has not spread.
STAGE
3
The cancer has spread into the lymph nodes that drain the region of skin concerned.
STAGE
4
There is disease outside the regional area. The melanoma has spread to distant lymph nodes or to organs such as the lungs, liver, or brain.
The risk of being diagnosed with melanoma of the skin by the age of 30 has more than halved in 23 years
In 1982, the risk of being diagnosed with melanoma by the age of 30 was around 1 in 600 people. Incidence risk trended upwards and in 1997 has risen to around 1 in 430 people (Figure 1).
From 1997, the risk of melanoma by the age of 30 began to fall. Based on current projections, in 2020 the risk of being diagnosed with melanoma by the age of 30 (estimated at around 1 in 1,170 people) has fallen to less than half of the risk in 1997 (Figure 1).
Following years of consistent decline, the risk of death from melanoma by the age of 30 in 2020 is estimated to be less than one-sixth of the risk in 1982 (1 in 62,000 persons in 2020 compared with 1 in 9,100 persons in 1982) (Figure 1).
Figure 1: Incidence and mortality risk by the age of 30, melanoma of the skin, persons
Note: Incidence risk for 2017–2020 and mortality risk for 2019 – 2020 are based on projections.
Source: AIHW Australian Cancer Database 2016 and National Mortality Database
The risk of being diagnosed with melanoma of the skin by the age of 60 peaked in the 1990’s
In 2005, and following years of increasing risk from 1982, melanoma incidence risk by the age of 60 began to fall and then stabilise from around 2012 (1 in 56 people in 2005 to an estimated 1 in 65 people in 2020) (Figure 2).
The large difference between the incidence risk and mortality risk reflects the relatively high survival rates for melanoma when considered in the context of other cancers.
The risk of death from melanoma by the age of 60 decreased consistently from 1982; from 2013 melanoma mortality risk decreased more sharply (from 1 in 650 in 1982 to 1 in 850 in 2013 and an estimated 1 in 1,600 in 2020) (Figure 2).
Figure 1: Incidence and mortality risk by the age of 30, melanoma of the skin, persons
Note: Incidence risk for 2017–2020 and mortality risk for 2019 – 2020 are based on projections.
Source: AIHW Australian Cancer Database 2016 and National Mortality Database
The risk of death from melanoma of the skin peaked in 2013
The lifetime risk of being diagnosed with melanoma is estimated to have tripled since 1982 (1 in 46 people in 1982 to an estimated 1 in 15 people in 2020) (Figure 3). Considering the younger population’s melanoma of the skin incidence risk has been decreasing and incidence risk by the age of 60 has been stabilising, the continuation of increasing melanoma incidence risk is driven by risks from the older population.
Part of the increase in the total population’s risk of being diagnosed with melanoma is due to increasing life expectancy. Essentially, the ageing population increases the proportion of people living to ages for which melanoma is generally more common (Figure 3).
The lifetime risk of death from melanoma continued to rise until 2013 (Figure 3). Please note that lifetime risk is not the risk for the 'average lifetime', it includes all people within the population and in very broad terms may be considered as risk by age 100 and more.
Figure 3: Lifetime incidence and mortality risk, melanoma of the skin, persons
Note: Incidence risk for 2017–2020 and mortality risk for 2019 – 2020 are based on projections.
Source: AIHW Australian Cancer Database 2016 and National Mortality Database
In 2013, the total population’s risk of death from melanoma was around 1 in 110 people; the lifetime melanoma mortality risk in 2013 had more than doubled from 1982 (1 in 240 people). Since the 2013 peak, lifetime melanoma mortality risk is estimated to have fallen to 1 in 140 people (Figure 4). Sharply decreasing mortality risk in conjunction with increasing incidence risk is indicative of improving survival outcomes for those diagnosed with melanoma (Figure 4).
Figure 4: Lifetime mortality risk, melanoma of the skin, persons
Note: Mortality risk for 2019 – 2020 are based on projections.
Source: National Mortality Database
The lifetime risk of death for males from melanoma of the skin has fallen strongly
The decrease in lifetime mortality risk from 2013 is driven largely by reductions in the comparatively high risk for males (1 in 80 in 2013 to an estimated 1 in 104 in 2020). For females, the lifetime risk of death also fell but at a slower rate (1 in 185 in 2013 to an estimated 1 in 197 in 2020 (Figure 5).
Figure 5: Lifetime mortality risk, melanoma of the skin, by sex, 1982–2020
Note: Mortality risk for 2019 – 2020 are based on projections.
Source: National Mortality Database
For both sexes, the lifetime risk of being diagnosed with melanoma continues to increase (figure 6) but the lifetime mortality risk for melanoma is starting to decrease.
While melanoma mortality risk peaked in 2013, impacts of an ageing population (that is, more people living to ages where melanoma incidence rates are higher) will continue to place upwards pressure on the risk of being diagnosed with melanoma and in turn the risk of death from melanoma; this may be particularly true for the ageing populations living in times when ‘Sunsmart’ awareness was less.
Figure 6: Lifetime incidence risk, melanoma of the skin, by sex, 1982–2020
Note: Incidence risk for 2017–2020 are based on projections.
Source: AIHW Australian Cancer Database 2016
Information about the risk data, terms used and where to find melanoma data
About the risk data
This paper uses a risk method that adjusts for competing mortality; Cancer data commentary no.1 provides help in understanding cancer risk methods and concepts.
Risk within this paper outlines the risk within the Australian population; an individual’s risk may be different depending on their own risk factors (for example, a daily smoker may have a higher risk of developing types of cancer where smoking is a risk factor).
Cancer incidence risk in 2017–2020 and cancer mortality risk in 2019–2020 are projections; actual data informs other years.
Terms used
Lifetime risk refers to the risk of (being diagnosed with or dying from) melanoma of the skin for the total population. Lifetime risk is not the risk of the ‘average lifetime’; it is risk by age 100 and greater (to the oldest person/s in the population for the year).
Melanoma incidence risk refers to the risk of being diagnosed with melanoma of the skin.
Melanoma mortality risk refers to the risk of dying from melanoma of the skin.