Brittany L. Berlin, Florida Atlantic University High School, Boca Raton, Florida, USA
Summary
Skin cancer is a global epidemic approaching millions of cases annually on a worldwide scale. The prevalence of skin cancer varies in different parts of the world, with Australia and New Zealand amongst the highest. Environmental factors, such as an increase in exposure to ultraviolet radiation in the Southern Hemisphere, cause a higher incidence rate of skin cancer in these countries. Policy initiatives promoting protection of the ozone layer and advocating for reducing climate change will significantly decrease the prevalence of skin cancer. Public health measures such as educating the public on sun protective measures at a young age and investing in infrastructure to promote sufficient areas of shade have been useful to curb this growing crisis.
Introduction
Skin cancer is one of the most common forms of cancer worldwide. The two broad classifications of skin cancer are: nonmelanoma and melanoma skin cancers. Although it is a large category, the two most frequent subtypes of nonmelanoma skin cancer are basal and squamous cell carcinomas.
Figure 1: Morphology of characteristic basal cell carcinoma, squamous cell carcinoma, and melanoma (Skin Cancer Screening, n.d.).
Nonmelanoma skin cancer has been increasing in both incidence and prevalence over the past several decades and now ranks as the fourth most common type of cancer following female breast, lung, and prostate carcinomas (Sung, 2021). It has been estimated that one in every three cancers diagnosed is skin cancer (WHO, 2017). These numbers are likely underestimated as many countries do not have cancer registries that track nonmelanoma skin cancers which further emphasizes the many millions affected by skin cancer throughout the world. In the United States alone, the cost for treating melanoma and nonmelanoma skin cancer is estimated to exceed $8 billion dollars annually (Aggarwal, 2021). Globally, the prevalence of skin cancer exhibits geographic variation. Nonmelanoma skin cancer is the most frequently diagnosed form of cancer in Australia and New Zealand for both men and women (Cancer Council Australia, 2020).
Figure 2: Graph depicting rates of skin cancer in countries reporting the highest incidence globally (Statista, 2020).
Risk Factors
Exposure to sunlight is a risk factor in the occurrence of both melanoma and nonmelanoma skin cancers. A history of multiple sunburns is a predisposing factor to individuals developing skin cancer (Wu et al, 2016). The different levels of ultraviolet radiation in parts of the world helps to explain the disparate rates of prevalence among different countries (Perera, 2015). Australia has one of the highest incident rates of nonmelanoma skin cancer in the world as its location in the southern hemisphere exposes its inhabitants to a greater intensity of ultraviolet radiation (Perera, 2015). Additionally, the depletion in the ozone layer contributes to an increase in solar ultraviolet (UV) radiation reaching the surface of the Earth. For every 10 percent decrease in the ozone layer, estimates show 300,000 non-melanoma and 4,500 melanoma new cases will occur (WHO, 2017). Global warming also has a significant influence on the incidence of skin cancer. It has been estimated that a 2-degree Celsius increase in temperature will result in a 11% global increase in skin cancer by 2050 (Van Der Leun and de Gruijl, 2022). Cultural behaviors and job opportunities in different regions of the world are additional contributing factors to variations in global rates of skin cancer. A study in the British Journal of Dermatology revealed a 77% higher risk for squamous cell carcinoma in those individuals who worked outdoors (Schmitt, 2011). Another risk factor accounting for different diagnosis patterns globally is the presence of arsenic in water supplies and food which can predispose individuals to developing skin cancer and is of particular concern in developing nations (Oberoi, 2014).
Solutions
Public health experts play a key role in helping to combat the rising prevalence of skin cancer around the globe. Given the high incidence of both nonmelanoma and melanoma skin cancers in Australia, the public health community has helped to enact policies to curb the rise of skin cancer. Preventative strategies include marketing campaigns emphasizing the importance of sun protection as well as infrastructure being constructed with more shaded areas in parks, playgrounds, and schools throughout the country.
Education has also been stressed with the importance of public awareness on the importance of early detection, regular complete skin cancer surveillance exams with physicians, and the warning signs to notice during self-examination. The popular acronym, ABCDE for melanoma with A standing for Asymmetry, B for change in border, C for change in color, D for increase in diameter, and E for evolving, has been effective in communicating dangerous warning signs of changing moles.
Figure 3: Educational pamphlet documenting the ABCDEs of Melanoma warning signs (Kim, n.d.).
Public policy environmental initiatives are key as depletion in the ozone layer contributes to an increase in solar UV radiation reaching the surface of the Earth and the consequent well documented association between skin cancer and exposure to ultraviolet radiation. Adoption of The Montreal Protocol in 1987 has been successful in preventing skin carcinomas worldwide. This international treaty aims to protect the stratospheric ozone through limiting industrial production and consumption of known ozone-depleting substances. To date, the success of this agreement has resulted in a decreased incidence of 20 million cases of skin cancer globally (Parker, 2021). Legislation banning the use of tanning beds by minors has been successfully enacted in several parts of the United States to decrease new cases of skin cancer. Morbidity and mortality associated with aggressive nonmelanoma skin cancers and melanoma can also decline with the use of recently developed pharmacologic agents. Emerging therapies are effective but quite expensive and often not available to people suffering from these advanced skin carcinomas in developing nations where they are needed the most due to limited access to health care services (Gutzmer & Solomon, 2019).
Conclusion
Skin cancer is a global epidemic where prevention can play a significant role in addressing this growing worldwide crisis. Education about proper skin care in personal lifestyle choices as well as the importance of recognizing early signs of skin cancer can drastically decrease the incidence of new cases. The continued efforts of multinational companies and governments to protect the ozone layer need to be encouraged to reduce the prevalence of skin cancer on a worldwide scale. Global endeavors combating global warming will be important to prevent additional cases of skin carcinoma. With early intervention and education leading the way, preventative measures can be at the forefront of mitigating cases of skin cancer.
References
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