DNA damage induced by UVA and UVB in squamous cell carcinoma progression [ 2002 - 2002 ]

Research Grant

Researchers: Dr Alexandra Jones (Principal investigator) ,  Prof Gary Halliday ,  Ross Barnetson

Brief description Australia has the highest incidence of skin cancer in the world. This results from immigration of individuals with fair skin to Australia. Skin cancer is three times as common as all other cancers combined. Overall, the incidence of skin cancer continues to rise in Australia and it will be several years before the true effectiveness of preventative programs are known. In the meantime, 1000 Australians die each year from skin cancer. Modern sunscreens, even those with high SPF and labelled as broad spectrum do not protect very well from UVA, though they are very effective UVB filters. Most sunscreens absorb or reflect only about 50% as much UVA as UVB. Thus sunscreen use alters the spectrum of UV received. This is an important issue, because if sunscreens are used to prolong sun exposure they will selectively increase the amount of UVA reaching the skin, and the sun contains a lot more UVA than UVB. There is only limited evidence to suggest they protect from skin cancer in humans whereas there is good evidence that they protect from precursor lesions. We have developed a new hypothesis, that UVB is primarily responsible for development of preneoplastic lesions (solar keratosis and dysplastic nevi) whereas UVA plays a relatively more important role in their progression to malignancy. This hypothesis would explain why sunscreens are more effective at preventing nevi and solar keratosis formation than they are at preventing melanoma and squamous cell carcinoma. Until the action spectrum defining the wavelengths responsible for skin cancer induction is known, the optimal methods for protection from skin cancer will be difficult if not impossible to design. That different wavelengths may be involved in different phases of skin cancer development in humans is a novel hypothesis: if it is correct it will have profound implications for both the design of sunscreens and our current public health programmes for skin cancer prevention.

Funding Amount $AUD 65,000.00

Funding Scheme NHMRC Project Grants

Notes Standard Project Grant