According to a new research, sunscreen alone should not be relied on to prevent malignant melanoma, a deadly form of skin cancer.
The British researchers back public health campaigns calling for sunscreen to be combined with other ways to protect the skin from sun, such as hats and shade.
The new study, an animal research, published in Nature, reveals more about how UV light induces cancer in skin cells.
Sun exposure is a well-known risk factor for melanoma skin cancer.
But, until now, the molecular mechanism by which UV light damages DNA in skin cells has been unclear.
In the new study, scientists at the University of Manchester looked at the effects of UV light on the skin of mice at risk of melanoma.
This allowed them to examine the effects of sunscreen in blocking the disease.
“UV light targets the very genes protecting us from its own damaging effects, showing how dangerous this cancer-causing agent is,” said lead researcher Prof. Richard Marais.
“Very importantly, this study provides proof that sunscreen does not offer complete protection from the damaging effects of UV light.
“This work highlights the importance of combining sunscreen with other strategies to protect our skin, including wearing hats and loose fitting clothing, and seeking shade when the sun is at its strongest.”
The researchers found that UV light caused faults in the p53 gene, which normally helps protect the body from the effects of DNA damage.
The study also showed that sunscreen could reduce the amount of DNA damage caused by UV, delaying the development of melanoma in mice.
But it found sunscreen did not offer complete protection and UV light could still induce melanoma, although at a reduced rate.
Another concern is the fact that any post-sunburn inflammation has the potential to cause cancer cells to migrate. According a study conducted at the University of Bonn in Germany, there is a strong link between UV-related skin inflammation and the spreading of cancer cells in blood vessels. Essentially this means that a bad sunburn can spread cancer from organ to organ, and it does this through the alteration of pigment cells in the dermis. Thankfully, ointments such as mometasone are able to swiftly end inflammation brought on by too much sun.