The number of new melanoma cases, the most serious form of skin cancer, have been increasing each year for the last 30 years, to include more young people from 15-29 years of age. By 2015, the American Academy of Dermatology estimates that 1 in 50 Americans will develop melanoma in their lifetime.
About 75 percent of skin cancer deaths are from melanoma, according to the AAD. The main reason melanoma is deadly is due to its spread, or metastases.
Now a new study based on the pioneering work of Dr. Claire Lugassy and Dr. Raymond Barnhill, a husband and wife research team at UCLA’s Jonsson Comprehensive Cancer Center, offers additional proof of how deadly melanoma cells spread in the body.
It is well established that melanoma cells can spread through the blood to accumulate and form new tumors in other parts of the body away from the original tumor. This is how a small, seemingly unimportant, skin cancer becomes life-threatening by spreading to the brain, lungs, liver or other organs.
The UCLA team also found that melanoma cells are tendriled and can travel throughout the body by “creeping like tiny spiders” along the outside of blood vessels or nerves until they reach an organ or other point where they accumulate to form new tumors.
Perhaps just as remarkable, the cells can do this without ever entering the blood stream. Lugassy and Barnhill termed this phenomenon “extravascular migratory metastasis” or EVMM.
Although Lugassy and Barnhill’s initial finding was once controversial, it has now revolutionized knowledge about how cancer spreads from its origin, known as primary melanoma, to distant organs of the body where they grow secondary tumors.
“EVMM potentially explains why there is a delay between the detection of the primary cancer and the appearance of distant metastasis,” Barnhill said in a statement.
In this latest study, published March 6, 2014 in the journal Nature, Lugassy and Barnhill’s team at UCLA collaborated with a team from the University of Bonn, Germany, led by Dr. Thomas Tüting, to show that exposure to ultraviolet (UV) radiation is a catalyst of melanoma cell migration.