Ultraviolet A and melanoma: a review

Area of Science:

• Dermatology and Cancer Research

Background:

• Melanoma incidence and mortality rates have increased, with ultraviolet (UV) radiation exposure cited as a primary cause.
• Sunburns, linked to UVB radiation, are a known melanoma risk factor, but UVA's role remains controversial.

Purpose of the Study:

• To review the English-language literature on the potential role of UVA radiation in melanoma development.
• To synthesize evidence regarding UVA's biological effects and epidemiological associations with melanoma.

Main Methods:

• Literature review of scientific evidence on UVA exposure and melanoma.
• Analysis of studies on UVA-induced DNA damage, mutations, and immunosuppression.
• Examination of animal models and human epidemiological data.

Main Results:

• UVA causes DNA damage through photosensitized reactions and oxygen radical species.
• UVA can induce mutations in cell lines and melanomas in animal models (Xiphophorus fish, opossum).
• UVA exposure is linked to immunosuppression and potentially increased melanoma risk in some human studies (sunbeds, PUVA therapy).

Conclusions:

• Basic scientific evidence indicates harmful effects of UVA on DNA, cells, and animals.
• Epidemiological and clinical data are inconclusive but suggest a potential role for UVA in melanoma pathogenesis.
• Further research is necessary to definitively establish UVA's contribution to melanoma development.