On this episode of Kentucky Health, host Dr. Wayne Tuckson speaks with Dr. Michael Egger, a surgical oncologist with the Brown Cancer Center at UofL Health. Dr. Egger discusses diagnosing, treating, and preventing melanoma, a life-threatening form of skin cancer.
How Melanomas Are Diagnosed
The most common types of skin cancers are basal cell and squamous cell carcinomas, Egger says. These cancers appear on surface areas of the skin exposed to excessive sunlight, they are slow growing, and they are less likely to spread to other parts of the body than melanomas are. Most carcinomas can be successfully removed.
Melanoma is “a different kind of skin cancer,” Egger says. “It originates from the melanocytes, which are the cells that give us our pigment, that make us either lighter or darker.”
The most common cause for melanoma also is exposure to ultraviolet (UV) radiation through sunlight. It is most often diagnosed in people in their 60s and 70s, but Egger says that in recent years there has been an uptick in melanoma diagnoses in younger adults.
“The two biggest risk factors for melanoma are having fair skin and then sun exposure,” Egger says. But he adds that use of tanning beds, which expose the skin to UV light in a controlled setting, are also associated with a higher risk of getting melanoma.
Such exposure is more damaging if it occurs at high intensity for a short duration rather than longer periods at lower levels, he explains. If the high-intensity exposure happens at a young age, that’s worse.
“One of the highest risk factors for developing melanoma would be having blistering sunburns, especially as a child or young adult,” he says.
Persons with fairer complexions are at a higher risk for melanoma, but Egger cautions that Blacks and Latinos can also get the disease. Those with darker skin are at higher risk for developing acral litigious melanoma, a type of the disease that appears on the palms of the hands or the soles of the feet.
People can also develop melanoma in the mucosal membranes of the anal canal and in an eye – areas of the body that also produce melanin. However, Egger says these forms of melanoma are far less common than ones caused by sun exposure.
“Melanomas are typically found either through dermatology screenings or skin exams, or (the patient) comes in with a problem – a funny-looking mole,” Egger says. “They can develop oftentimes as a new mole, something that’s come up where they had no other spot before, a pigmented lesion that is itching, bleeding, or causing problems. Or sometimes it’s a mole that’s changed. Perhaps they’ve had a mole for their whole life – it’s been a round, brown, innocent-looking mole, and all of a sudden, it’s changed.”
Prevention Strategies and the Importance of Self-Screening
“Certainly, prevention is the best thing – never developing a melanoma is the best way not to die from a melanoma,” Egger says. “Protecting yourself from chronic sun exposure and blistering sunburns is best done with a combination of sunscreen, mechanical barriers (such as) floppy hats and long-sleeved shirts, and avoiding high sun exposure, especially in the middle of the day when the UV rays are most intense.”
Egger recommends applying a sunscreen with a sun protection factor (SPF) of 30 or higher before going outside for an extended period of time.
“Having a history of melanoma or trying to avoid melanoma does not mean you need to live in the basement,” says Egger. “You need to be outside and be healthy, and that’s all good – you just need to do so safely and with protection.”
If a person does notice a new mole on their skin or changes in one they’ve had for a while, it’s time to see a dermatologist. Self-screening is very important to catch melanomas when they are small and have not had the time to grow and potentially spread to other parts of the body. The guidelines to assist with self-screening correspond to the start of the alphabet, says Egger.
“We’re looking for asymmetry, where (the mole) is lopsided in appearance. Irregular borders, so rather than having a nice, smooth circle, it sort of gets scalloped out. And C is color,” he says. “Brown, sort of regular-looking lesions are probably more innocent than those that have a sort of inky, black look, or what we call variegated color where some areas are darker than the others.
“D is diameter,” he continues. “We typically say anything greater than six millimeters in size, which is about the size of the tip of a number 2 pencil eraser. And then E means evolution, which really means changes – a change in lesions over time.”
It’s important to remember that people develop skin lesions as they grow older. Egger says most of them will be benign, but since melanoma risks increase with age, he advises patients to be vigilant when conducting self-exams of their skin and to take note of any blemish that looks suspicious or that changes.
Treatment Options and Success with Immunotherapy
If a suspicious lesion is found, the dermatologist will shave off part of it during an office visit and send it to a pathologist.
“From there, we can make the diagnosis and decide on the treatment,” Egger says.
If a melanoma is diagnosed, Egger says the thickness of the lesion determines the path of subsequent treatment.
“That’s measured under the microscope, and we characterize melanomas as either thick, thin, or intermediate thickness,” he explains. “Thin melanomas without any other sort of adverse features or high-risk features under the microscope are treated by excising the area with a rim of normal skin around it, and that’s typically all you need to do.”
For intermediate thickness and thick melanomas, Egger says they will be staged during the initial excision process in order to detect if any of the cancer has spread to nearby lymph nodes.
When removing the melanoma, Egger says that for lesions smaller than a millimeter in size, the surgeon will cut out an area of skin measuring a centimeter that encircles it. For any lesion bigger than a millimeter in diameter, the excision will be two centimeters. Egger says those measurements may seem small but are in fact large enough to leave a visible scar once the surgery is completed.
A procedure called Mohs micrographic surgery is commonly used for less invasive skin cancers, but some surgeons also use it for early-stage melanomas, says Egger.
“It’s a technique in which a very narrow margin (of skin) is taken on skin lesions, and those margins are evaluated essentially in real time under the microscope,” he explains. “They are checked, and if additional margins are needed, (the surgeon) takes additional margins.”
At advanced stages, melanomas may spread to distant organs, the lungs and brain being the most common. Egger says using chemotherapy in the traditional sense has never worked well in treating metastatic melanoma. But he says the use of immunotherapy – drugs that signal a patient’s immune system to recognize and destroy cancer cells in the body that previously had been undetected – has been a “game changer.”
“What we sort of figured out a way to do is to turn the immune system back on – we basically cut the brakes, if you will,” he continues. “Cut the inhibition of the immune system in order to allow the immune system to wake up, recognize the melanoma, and attack it accordingly.”
Egger says that until about 15 years ago, the five-year survival rate for metastatic melanoma was around 10-15 percent. Now, the survival rate is up to 30-35 percent. He says that’s due to the success of immunotherapy for both melanoma and lung cancer.
Patients who have surgery to remove melanomas that have not spread to lymph nodes or farther are monitored closely after the procedure. Egger says the surveillance is more oriented toward spotting a new, developing melanoma rather than a recurrence in the original area.
“Typically for thin-melanoma patients, they’re seen by their dermatologist for a total body scan every three months initially,” says Egger. “Then we start spacing that out over time.”