Does ultraviolet (UV) light exposure cause melanoma, a type of skin cancer?

From the Guidelines

Yes, UV light exposure is a significant risk factor for melanoma, the deadliest form of skin cancer, as supported by the most recent and highest quality study 1. While some studies have questioned the strength of this association, the scientific consensus based on extensive epidemiological evidence supports that UV radiation from sunlight or tanning beds contributes to melanoma development. UV exposure causes DNA damage in skin cells, leading to mutations that can trigger cancer formation. The relationship is complex - melanoma can occur in areas with minimal sun exposure, and genetic factors play an important role. However, this doesn't negate the UV connection. Both UVA and UVB rays contribute to skin cancer risk, with UVB more strongly linked to sunburn and UVA penetrating deeper into the skin. While UV exposure more commonly causes basal cell and squamous cell carcinomas, it remains a significant risk factor for melanoma as well. Some key points to consider include:

• The incidence of melanoma has been increasing among white Americans, from 8.7 per 100 000 persons in 1975 to 27.6 per 100 000 in 2008, as reported by 1.
• Increased ultraviolet (UV) light exposure of a genetically predisposed population seems to be at least in part responsible for an ongoing increase in incidence and mortality over recent decades, as stated in 1.
• Prevention of UV exposure, including the regular use of sunscreen, has been shown to diminish the incidence of primary cutaneous melanomas in an Australian population, as found in 1. Sun protection measures including sunscreen, protective clothing, seeking shade, and avoiding tanning beds are recommended to reduce melanoma risk, alongside regular skin checks for early detection. It is essential to note that the USPSTF found convincing evidence linking UV radiation exposure during childhood and youth to a moderately increased risk for skin cancer later in life; for adults, adequate evidence links UV radiation exposure to a small increase in risk for skin cancer, as reported in 1. Therefore, it is crucial to prioritize sun protection and early detection to minimize the risk of melanoma and other skin cancers.

From the Research

UV Radiation and Skin Cancer

• UV radiation is a recognized risk factor for skin cancer, but the associations are complex and vary between different types of skin cancer 2.
• Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are more strongly associated with UV radiation exposure than melanoma 2, 3.
• A study found that a history of severe sunburns at a young age was associated with increased risks of all skin cancers, including melanoma, BCC, and SCC 2.

Melanoma and UV Radiation

• The relationship between UV radiation and melanoma is not as clear-cut as it is for BCC and SCC 2, 3.
• One study found that there was no positive linear association between total UV score and the risk of melanoma 2.
• However, another study suggested that exposure to UV radiation is associated with approximately 65% of melanoma cases 3.

Prevention of Skin Cancer

• Sun protection measures, such as wearing protective clothing, using sunscreen, and seeking shade, are recommended to prevent skin cancer 4, 5.
• A review of sun protection in Australia and internationally found that sunscreen is the most frequent method of sun protection used, but that other forms of protection, such as clothing and seeking shade, need to be emphasized 5.
• A study on the role of UV radiation in the development of BCC found that UVB radiation is believed to play a greater role in BCC formation than UVA radiation 6.