January 31, 2018
Regular sunscreen use by all Australians could drive down the burden of melanoma by up to 34 per cent by the year 2031, according to a study by QIMR Berghofer Medical Research Institute.
The findings mean an estimated 28,071 fewer melanomas would be diagnosed in Australia over that time.
The head of QIMR Berghofer’s Cancer Control Group, Professor David Whiteman, said his research team predicted the likely impact of regular sunscreen use on melanoma rates.
“Ultraviolet radiation from sunlight is the main environmental cause of melanoma, with researchers estimating that it causes anywhere between 63 per cent and 90 per cent of all melanoma cases,” Professor Whiteman said.
“With melanoma rates still increasing in most populations across the world, it makes sense to look at the potential public health benefit of something as simple – but effective – as wearing sunscreen regularly.
“Broad spectrum sunscreens provide protection from the sun’s harmful rays and if applied daily, can reduce the risk of developing melanoma.”
Professor Whiteman said the study used existing publicly available data to calculate the potential impact in seven different modelling scenarios.
He said data about the effectiveness of applying daily sunscreen on melanoma came from QIMR Berghofer’s long-running Nambour skin cancer prevention trial.
The investigators modelled a number of hypothetical scenarios for the Australian population, including mandatory sunscreen application for people aged 45-65 years, for all school-age children and, in the ‘best case’ example, assumed 100 per cent of the population used sunscreen at all times.
Professor Whiteman said the study found increased regular sunscreen use by older Australians would have the greatest overall impact on melanoma rates in the short-term.
“The burden of melanoma is highest in the older population, so the most effective sunscreen intervention in the short-term to reduce melanoma was within that population,” Professor Whiteman said.
“However, that only holds true if we assume the benefits of sunscreen use have an immediate and equal effect across all the age groups we looked at.
“Our school-age intervention led to a much more modest reduction in melanoma rates by year 2031. This is because we were only looking at the benefit after a relatively short timeframe, when we know melanomas usually occur in later life.
“We cautiously examined the possible effects of everyone wearing sunscreen from school-age to the year 2081, and found that it would reduce the burden of melanoma by around 20 per cent.
“That result is however less reliable due to the significant period of time we modelled.
“Given that sun exposure in early life may be an important factor in melanoma development, it is also possible that the benefits of regular sunscreen use are greater in children than this study suggests.”
Professor Whiteman said that despite sunscreen being protective against melanoma, there were still many variables that could affect a forecast reduction in cases.
“Sunscreen use is difficult to monitor,” Professor Whiteman said.
“Even if participants in a study were to say they applied sunscreen every day, we know that there are differences in the amount of sunscreen a person uses.”
Despite that, Professor Whiteman said the study’s findings were clear.
“The evidence strongly suggests that people who use sunscreen regularly significantly reduce their risk of developing melanoma,” he said.
“However, regular sunscreen would also reduce the public health burden of other types of skin cancer, too.”
Professor Whiteman said the study also predicted the impact of regular sunscreen use by the Caucasian population of the United States, finding it would lead to 796,872 fewer melanomas.
He said that equated to a predicted decrease in melanoma cases of about 38 per cent.
The study was published in the British Journal of Dermatology.