UICC World Cancer Congress 2006

“Objective” To provide an overview of the steps that need to be taken now to address rising skin cancer rates and the emerging issues relating to vitamin D and sunbeds that have the capacity to undermine current skin cancer prevention efforts.

“Method” Scientific review of peer reviewed literature

“Results” The number of melanoma cases worldwide is increasing faster than any other cancer. The annual increase in incidence rate varies between populations, but in general has been in the order of 3-7% per year for fair-skinned Caucasian populations. In the UK, the number of skin cancer cases has more than doubled since the early 80s and in the USA, malignant melanoma was the most rapidly increasing malignancy in both sexes between 1973-1997. Of concern within this context, is that in many large western populations, pro-tan believes remain strong, despite high awareness of the risks of skin cancer.

Fortunately, based largely on Australian experience, there is good evidence to know what is required to deliver effective population-based skin cancer prevention programmes. Importantly, programmes need to be comprehensive in approach across a broad range of settings and be underpinned by a broad mass media campaign and research over a sustained period of time. In this context, not only can skin cancer prevention programmes reduce the health burden associated with the disease, it can also be cost effective. The lessons learnt in running effective skin cancer control programmes have also application across other population based preventive health issues.

In recent years, emerging issues relating to vitamin D and artificial tanning sunbeds are posing significant challenges to those working in skin cancer control. Evidence is accumulating that vitamin D has a positive impact on our health and therefore it may be necessary to reconsider our public health advice relating to skin cancer prevention. There is high-level evidence for the beneficial effects of sun exposure in maintaining adequate vitamin D levels to protect against osteoporosis and bone fracture. There is also some evidence that sun exposure may have a possible beneficial effect with other cancers such as breast, prostate, bowel, or non-Hodgkin lymphoma and autoimmune diseases such as multiple sclerosis. The biological pathways underlying these empirically observed observations are still not clear and in some instances the epidemiological evidence is equivocal. Nevertheless, despite these limitations, evidence around these issues continues to achieve considerable media attention and therefore has the potential to undermine long standing skin cancer prevention messages.

In this context, a balance is required between avoiding an increase in the risk of skin cancer while at the same time, receiving enough ultraviolet radiation exposure to enable the body to maintain adequate vitamin D levels. Fortunately, the Global UV Index can provide some guidance as to when sun protection should be promoted during the time of year and day to ensure the two issues are not seen in conflict. In particular, sun protection only should be promoted when the UV index is 3 (moderate)or above. In this context, sun protection is unlikely to increase osteoporosis risk.

With appropriate refinements of the sun protection message, sun protection programs do not have to compete with the human need for vitamin D, the two messages can be quite complementary. In high latitude countries with very low UV levels for a significant proportion of the year, the increased use of vitamin D fortification in food and supplementation for high-risk individuals should be considered. Further research is required to understand the relationship between vitamin D and risk of cancer and autoimmune diseases and to determine how much sun exposure is necessary to achieve adequate vitamin D levels. This information will help determine the right balance between the need for vitamin D versus the known benefits of sun protection.

An additional challenge has been the continued growth of the artificial tanning sunbed industry. The sunbed industry is based on the glorification of a tan, the antithesis of the objectives of those working in skin cancer prevention. In the United States, the sunbed industry continues to grow with a $1 billion a year turnover and 30 million patrons visiting sunbeds annually. This growth in patronage has also been seen in Europe where it has gone from less than 5% of the adult population in Belgium, France and Germany in 1980, to 33% by 1995. Of concern is that a recent ruling by the Canadian Competition Bureau allows sunbed operators to claim that sunbed use increases vitamin D levels. To tackle these issues, new approaches are needed to be developed to ensure greater regulatory control over sunbed operators. This includes restricting access to those under the age of 18, ensuring warning notices are placed in all cubicles and in the foyer area, ensuring all new clients to the establishment sign a consent form as well as ensuring all operators are adequately trained.

Despite any possible vitamin D benefit that may be derived from sunbed machines that emit UVB, their use should continue to be discouraged due to the intensity of the output of a well known carcinogen and the lack of controls that govern their use.

To appropriately manage these issues and to ensure high pro-tan believes don't continue to contribute to rising skin cancer rates, it will be necessary to ensure adequate steps are taken now and over the long term to address the rising mortality, morbidity and health costs associated with skin cancer.