Why Redheads Are At Risk for Melanoma

When it comes to guarding against skin cancer, routine sunscreen use is important for everyone. But for the redheads of the world, protection from the sun's rays is critical. That's because the one to two percent of the population who have red hair, freckles and fair complexions are at especially high risk of developing melanoma, the least common but most dangerous type of skin cancer.

Scientists at Beth Israel Deaconess Medical Center (BIDMC) are helping to explain why: In a study published in the journal Molecular Cell, the research team found that the same genetic variation that lends redheads their ginger-colored tresses is also linked to an important cancer-causing pathway.

"Melanoma, which is responsible for approximately 75 percent of all skin-cancer deaths, originates in pigment-producing skin cells called melanocytes," explains Wenyi Wei, PhD, a scientist in the division of cell biology in BIDMC's Cancer Research Institute. "Melanoma develops through a multi-step process of genetic mutations (changes in cells' normal DNA sequences) that ultimately increase a person's susceptibility to ultraviolet (UV) radiation."

Dr. Wei's discovery hinges on the melanocortin-1 (MC1R) receptor gene, which helps determine a person's hair color and skin tone. "When it is working properly, the MC1R gene also plays a key role in protecting melanocytes from DNA damage caused by UV radiation," says Dr. Wei, explaining that the MC1R gene interacts with a tumor suppressor gene called PTEN to prevent the development of cancer. (Tumor suppressor genes prevent cells from uncontrolled growth and can help prevent tumor growth.)

But in redheads, whose MC1R genes are mutated or damaged, this protective PTEN mechanism is missing. Dr. Wei and his collaborators discovered through a series of experiments that exposure to UV radiation causes MC1R mutations to trigger the hyperactivation of a molecular pathway called the PI3K/Akt signaling pathway. The PI3K/Akt pathway is known to be responsible for a number of different types of cancer.

"Our findings provide a possible molecular mechanism as to why red-haired individuals with MC1R mutations are so much more susceptible to UV-induced skin damage than individuals with darker skin, resulting in a significantly higher frequency of melanoma," says Dr. Wei.  His lab is continuing their investigations to help identify drug inhibitors that might one day be used to treat this deadly disease.

How to Spot a Melanoma

The incidence of melanoma has risen rapidly in recent years: According to the National Cancer Institute (NCI) the number of melanoma cases among whites increased by more than 60 percent between 1991 and 2011.

Although redheads and fair-skinned individuals are at significantly higher risk for melanoma, anyone can develop this dangerous skin cancer.  The first sign of melanoma is often a change in the size, shape, color or feel of a mole or the appearance of a new mole; these skin cancers are often black or blue-black and "ugly looking."

Call you doctor if you have concerns or notice a new or unusual growth.e

To help spot a melanoma, the NCI recommends you remember "ABCDE":

• Assymetry: The shape of one half of the mole does not match the other half
• Border: The mole's edges are ragged, or irregular
• Color: The color is uneven and may include shades of black, blue, brown, tan, pink, or red
• Diameter: There is a change in size over time, usually an increase
• Evolving: The mole's appearance changes over the course of a few weeks or months.

Prevention is Key

Dermatologists recommend avoiding sun exposure, especially during the peak sun hours of 10 am and 2 to 4 pm. Wide brimmed hats and clothing, especially clothing that has sun protection woven are the best way to prevent harmful UV rays from reaching the skin. But, where the skin is exposed, a broad spectrum sunscreen with SPF 30 or higher can help protect the skin from burning.

Above content provided by Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.

Posted July 2015