Ultraviolet Radiation
Skin cancers are caused by ultraviolet radiation and can be prevented by sun protection and banning sunbeds.
A majority of skin cancers are caused by ultraviolet (UV) radiation. Keratinocyte skin cancers (basal cell and cutaneous squamous cell carcinomas) are the most common human cancers with over 13 million cases estimated each year worldwide. While rarely fatal, keratinocyte cancers cause substantial burdens of morbidity and cosmetic concern (most occur on the face). Melanoma is a more fatal form of skin cancer with about 69,000 deaths and 350,000 cases annually worldwide. In many countries skin cancers pose a significant economic burden due to their sheer numbers and the high cost of treatment for metastatic melanoma. (Figure 1)
Figure 1. Direct costs of melanoma skin cancers and squamous cell carcinomas and basal cell carcinomas combined, 2013 Euros (millions). In the US, total direct cost of skin cancers is 613.2 million Euros. 4% of the cost is from melanoma and 96% of the cost is from squamous cell carcinomas and basal cell carcinomas combined. In Australia, total direct cost of skin cancers is 422.6 million Euros. 13% of the cost is from melanoma and 87% of the cost is from squamous cell carcinomas and basal cell carcinomas combined. In Germany, total direct cost of skin cancers is 235.8 million Euros. 32% of the cost is from melanoma and 68% of the cost is from squamous cell carcinomas and basal cell carcinomas combined. In the United Kingdom, total direct cost of skin cancers is 149.1 million Euros. 19% of the cost is from melanoma and 81% of the cost is from squamous cell carcinomas and basal cell carcinomas combined. In Brazil, total direct cost of skin cancers is 75.5 million Euros. 63% of the cost is from melanoma and 38% of the cost is from squamous cell carcinomas and basal cell carcinomas combined. In Sweden, total direct cost of skin cancers is 66 million Euros. 43% of the cost is from melanoma and 57% of the cost is from squamous cell carcinomas and basal cell carcinomas combined. In Canada, total direct cost of skin cancers is 54.7 million Euros. 55% of the cost is from melanoma and 45% of the cost is from squamous cell carcinomas and basal cell carcinomas combined. In Denmark, total direct cost of skin cancers is 34 million Euros. 61% of the cost is from melanoma and 39% of the cost is from squamous cell carcinomas and basal cell carcinomas combined. In New Zealand, total direct cost of skin cancers is 32.1 million Euros. 18% of the cost is from melanoma and 82% of the cost is from squamous cell carcinomas and basal cell carcinomas combined.
UV radiation comes from the sun, filtered by stratospheric ozone. The UV Index measures the intensity of sunburn-causing UV reaching the Earth’s surface on a scale of 1 (low) to 11+ (extreme) and varies with latitude, altitude, time of day and year, cloud cover, and air pollution. In summer, the UV Index averages around 12 in Bangkok, Thailand (14°N); 9 in Sydney, Australia (34°S); 8 in New York, USA (41°N); 7 in Berlin, Germany (52°N) and 5 in St Petersburg, Russia (60° N). Cosmetic tanning devices also emit UV radiation, often stronger than summer sun, and are classified as human carcinogens; however, their use remains high, particularly in Europe and North America. (Figure 2) Banning these devices brings potentially high savings of lives and costs.
Figure 2. Sunbed prevalence (%) among females and males across different countries by year of survey since 2009. According to various surveys in different countries between 2009 and 2017, sunbed use among females was as high as 61.5% in one survey in 2010, but by 2017 had decreased to between 7.5 and 20%. Among males, sunbed use was around 15% in one survey in 2009, but has decreased to between 3 and 10% in 2016.
There is no such thing as a healthy tan.
Inherited risk factors for skin cancer, such as light skin and red hair, and having freckles and moles, influence the effects of ambient UV and occupational and recreational sun exposure. Skin cancer is rare in people with innately dark skin. Risk is higher with high UV exposure in childhood.
When the UV Index is 3+, skin can be protected by avoiding outdoor activities in the middle of the day; providing effective shade outdoors; wearing hats, clothing cover and sunglasses; and applying sunscreen of Sun Protection Factor 15+ or higher. In contrast to many European countries, Australia began implementing UV protection campaigns in the 1980s, and rates of melanoma are now decreasing in younger generations. (Figure 3)
ACCESS CREATES PROGRESS
Rates of melanoma are decreasing in young people in Australia.
Figure 3. Age-standardized incidence rates (world) per 100,000, invasive melanoma, persons aged <25 years by sex in Australia and England, 1990-2010. In Australia and England, melanoma incidence rates are generally higher in females than males. Melanoma rates have declined in Australia among females from 4.4 cases per 100,000 in 1990 to 1.3 in 2010. Among males in Australia, melanoma rates have declined from 3.3 cases per 100,000 in 1990 to 0.9 in 2010. In contrast, melanoma rates have have remained lower but stable in England among females with 1.1 cases per 100,000 in 1990 and 1.6 in 2010. Among males in England, melanoma rates have also remained lower but stable with 0.5 cases per 100,000 in 1990 and 0.7 in 2010.
Prevention of skin cancer by use of sun protection:
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Text:
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World Health Organization. Solar Ultraviolet Radiation: Global Burden of Disease from solar ultraviolet radiation. 2012.
Map:
Ferlay J, Ervik M, Lam F, et al. Global Cancer Observatory: Cancer Today. Lyon, France: IARC, 2018. Available from: https://gco.iarc.fr/today.
Figure 1:
Gordon LG, Rowell D. Health system costs of skin cancer and cost-effectiveness of skin cancer prevention and screening: a systematic review. Euro J Cancer Prev. 2015; 24:141–149.