Researchers have claimed that the incidence of malignant melanoma in adulthood can be dramatically reduced by the consistent use of sunscreen in infancy and childhood.

According to senior author John L. VandeBerg, Ph.D., the research was driven by the fact that, despite the increasing use of sunscreen in recent decades, the incidence of malignant melanoma, the most aggressive form of skin cancer, continues to increase dramatically.

VandeBerg said while sunscreen is highly effective in preventing sunburn, this paradox has led some to question whether sunscreen is effective in preventing melanoma caused by ultraviolet (UV) light.

Scientists at Texas Biomedical Research Institute have established the gray short-tailed opossum, a small marsupial from South America, as such a model, and tested an over-the-counter facial lotion containing SPF15 sunscreen for its ability to prevent UV-induced melanoma.

The Texas Biomed researchers found that the application of lotion containing sunscreen to infant opossums led to a 10-fold reduction in pre-melanotic lesions (known to progress to melanoma), in comparison to infant opossums receiving lotion that did not contain sunscreen.

This difference in the development of lesions occurred even when low doses of UV light were applied - so low that they caused no sunburn or even reddening of the skin in the opossums that did not receive sunscreen.

The pre-melanotic lesions did not appear until the infants had become adolescents (equivalent to early teenagers in humans), and prior experiments established that the pre-melanocytic lesions in opossums do not progress to melanomas until the animals are well into adulthood, as typically occurs in humans.

The study has been published in the scientific journal Pigment Cell and Melanoma.