Sunscreen can not prevent skin cancer

Even sunscreen with a high sun protection factor can not prevent skin cancer

06/12/2014

Manchester University scientists have investigated the molecular mechanisms underlying the development of skin cancer. Like the researchers around Martin Cook and Richard Marais in the trade magazine „Nature“ They have come to the surprising conclusion that even sunscreen with a high sun protection factor (LF) does not protect against the particularly aggressive malignant melanoma.

Although numerous studies have shown that skin cancer is epidemiologically associated with ultraviolet light (UV light), „but the molecular mechanisms have remained unclear“; the scientists justify their current study. They therefore investigated the role of changes in the growth gene BRAF in the development of melanomas. Show this gene „most common somatic mutations in melanoma.“ The researchers artificially induced corresponding mutations in the so-called melanocytes in mice and examined what effect the UV radiation subsequently unfolded in the animals.

Sunscreen can only delay skin cancer
The genetically manipulated mice were shaved on their backs during the study and exposed to UV radiation „mild sunburn in humans“ cause Marais and colleagues write. The skin of the mice was partially covered with sunscreen (LF 50) and with fabric. The one-time radiation has also in the supposedly sunscreen protected skin „Clonal expansion induced melanocytes and repeated doses of UV radiation resulted in increased melanoma load“, the scientists report. The investigation has shown that although sunscreens can delay the occurrence of UV-related melanoma, they only provide partial protection. The development of malignant black skin cancer with its help could not be completely prevented.

Better understanding of the development of black skin cancer
The scientists also found that the tumors formed „an increased number of single nucleotide variants“ and they watched „Mutations in the tumor suppressor Trp53 in about 40 percent of cases.“ This gene, in its healthy form, serves to suppress cancer cells. So far, science has not assumed that Trp53 plays an important role in melanoma. „However, we show that mutations of Trp53 drive BRAF-related tumor development and TP53 mutations are associated with UV radiation-induced DNA damage in human melanoma“, write Marais and Cook. The scientists thus provide a new insight into the molecular genetic basis of the development of malignant melanomas.

Recommendations for sun protection confirmed
With their study, the science of the University of Manchester in principle confirm the recommendations of the German Dermatological Society e.V. (DDG) and other associations for sun protection. The rule here is: avoid, dress, cream - in that order. „Only those who reduce the UV radiation to a level that is rel- evant to the skin, and who protect the sun, especially in times of very high UV intensity, can protect it“, reports the DDG. Since almost 80 to 90 percent of the normal UV radiation goes down between 11 am and 3 pm, the stay in direct suns should be avoided or minimized as far as possible during this time. In addition, it is important to pay attention to appropriate, protective clothing when staying in the sun. Not only children should necessarily wear a headgear (sun hat). For toddlers anyway, that is true „not at all the right sound“ should warn the DDG. Because in the first life years would come „The risk of decaying skin cancer in the course of the later life is de fi ned to that degree.“ Here, for example, it is always a warning sign when leeches develop in the early childhood.

Error in sunscreen - No reliance on sunscreen
Professor Eckhard W elm B ake of the work community The ma to lo gi p procedure (ADP) explained that many people still behave incorrectly when it comes to UV protection. Be here „The biggest failures are that the imprints in the sun are wrongly calculated, and that you can first of all rely on sun protection with tel.“ For example, the specified protective effect of the sunscreen can only be achieved if approximately two mil ts of sun protection are applied with tefe a square cent e of skin. According to the expert, this would require a bottle of sun protection cream per day for a three- to four-in-a-half time walking on the beach in the sun looker. „I never know one who thinks of it“, Breitbart emphasized. For example, inadequate sun protection should play a significant role in the still-increasing number of malignant skin cancers in Germany. Persons with a light skin, very large boisterous mothers and a large number of liver spots are especially at risk. (Fp)