This year, approximately 76,100 new cases of melanoma will be diagnosed – the deadliest form of skin cancer. Since exposure to ultraviolet light – from the sun and tanning beds – is a major risk factor for melanoma, wearing sunscreen is top of the list as a prevention aid. But now, a new study published in the journal Nature suggests that sunscreen alone is not enough to protect against the disease. Melanoma is a major concern in the US, with rates of the disease increasing for at least 3 decades. In an attempt to reduce the skin cancer burden, public health campaigns worldwide are trying to encourage people to cover up in the sun, as well as wear sunscreen on exposed areas of skin. For example, the National Council on Skin Cancer Prevention has declared the Friday before Memorial Day as “Don’t Fry Day” – a campaign that aims to raise awareness of overexposure to ultraviolet (UV) radiation. This latest study – conducted by The University of Manchester’s Cancer Research UK Institute and the Institute of Cancer Research, also in the UK – supports such campaigns.

UV light targets damage-preventing genes, even with sunscreen on To reach their findings, the research team analyzed the effects of UV light on 2-month-old mice with an abnormal BRAF gene, which is known to increase the risk of melanoma. The researchers found that on unprotected skin, UV light directly damages the DNA of pigment cells in the skin, which raises the risk of melanoma. Specifically, the team discovered that exposure to UV light leads to abnormalities in a gene called p53, which usually works to prevent DNA damage from UV radiation. After applying sunscreen to the skin of the mice, the team found it significantly reduced the level of DNA damage caused by UV radiation, which slowed development of melanoma. However, the researchers also found that sunscreen failed to offer total protection from UV light and that the radiation was still able to cause abnormalities in the p53 gene, just at a lower rate. Commenting on the findings, study author Prof. Richard Marais, a scientist at Cancer Research UK, says: “UV light has long been known to cause melanoma skin cancer, but exactly how this happens has not been clear. These studies allow us to begin to understand how UV light causes melanoma. UV light targets the very genes protecting us from its own damaging effects, showing how dangerous this cancer-causing agent is. Very importantly, this study provides proof that sunscreen does not offer complete protection from the damaging effects of UV light.”