THE ESSENTIAL
- Researchers have discovered a treatment that could regress dangerous birthmarks and prevent melanoma
- About one in 20,000 infants are born with what is called a congenital giant nevus
“Avoid major surgery“, this is the goal of researchers from the Massachusetts General Hospital (MGH) in the United States who published a study in the journal Cell on the management of giant moles.
Currently, when a child is born with a congenital giant nevus – a huge pigmented mole that can cover a large part of the face and body, many patients decide to have their child undergo surgery to remove the entire lesion, which can lead to significant and permanent scarring.
This is because of the appearance of the mole and also the risk of later development of skin cancer which is one of the deadliest childhood cancers.
Indeed, in this rare and still unknown skin anomaly today, the lesion is greater than or equal to 6 cm² at birth and as the child grows, this mole will grow proportionally.
Drug treatments
“The objectives of our study were to develop a series of animal models designed to elucidate the key biological characteristics of these lesions, and to test non-surgical drug treatments on the skin, aimed at regressing nevi cells, thereby eliminating the need for treatments. surgical“, says lead author David E. Fisher, physician scientist, director of the MGH Cancer Center Melanoma Program and director of the Cutaneous Biology Research Center at MGH.
They discovered that several drugs can be applied to the skin to regress the lesions, and that a topical drug, therefore for local use, also protects against skin cancer.
The models included mice engineered to express a gene called NRAS that contains a mutation known to cause most congenital giant moles in humans, as well as mice with skin grafts containing human congenital giant moles.
They were able to analyze the different phases of these nevi in order to better understand how they form and develop.
Significant regressions
Additionally, when scientists used these models to test local applications of single or combination drugs that block signaling pathways known to be activated by NRAS mutations, they found that some of the treatments resulted in significant nevi regressions.
A drug that stimulates a type of inflammatory reaction after application to the skin caused complete regression of moles after three treatments.
The therapy also offered complete prevention against the formation of skin cancers in mice.
“It is hoped that these results will pave the way for further refinements aimed at directly testing such skin treatments on patients with congenital giant nevi.“, says the scientist. “This work will include additional safety studies, potential improvements in efficacy, and further analysis of the underlying mechanisms. The overall goals are to prevent melanoma in these patients and also to avoid the disfigurement challenges posed by these lesions.“