What to know about melanoma, one of the deadliest forms of skin cancer
NEW YORK – Therapies approved over the past 15 years have transformed the treatment of melanoma, extending and improving the lives of patients even with late-stage cases. And other potential treatments are on the horizon.
On Aug 19, drugmakers Merck and Moderna announced preliminary results from a Phase 3 clinical trial suggesting that an experimental mRNA vaccine for melanoma patients reduced the risk that the cancer would recur or spread to other parts of the body.
There are also simple ways to reduce your risk, and to detect possible cases early while they are most curable.
Here’s what to know about melanoma, its treatments and how to protect yourself.
What is melanoma?
Melanoma is a cancer that typically starts in skin cells known as melanocytes that make the skin’s pigment. Compared with more common skin cancers that begin in squamous or basal cells, melanoma is more likely to spread to other parts of the body.
“It truly has a very aggressive behaviour and biology behind it,” said Dr Michael Davies, chair of the melanoma medical oncology department at the University of Texas MD Anderson Cancer Center.
Most melanomas appear as flat or slightly elevated blotches of dark colour on skin that has been frequently exposed to ultraviolet light, such as the scalp and face, arms, back and legs (though they can occur on areas that have never been exposed to the sun, too).
In a smaller share of cases, the growth may appear as a dark- or red-coloured bump and grow down into the skin, which can make it more difficult to detect.
A less common form, lentigo maligna melanoma, mostly afflicts older adults who have had significant sun exposure, and often appears as abnormally-shaped tan or brown spots on their heads or necks.
An even rarer type, called acral lentiginous melanoma, occurs on the hands and feet (specifically the soles, palms, fingers, toes or nail beds) and accounts for more than half of melanoma cases in those who are not white. (Musician Bob Marley died from this type of melanoma, which was at first misidentified as a bruise.)
Melanoma can also occur in the eyes or mucosal membranes such as inside the nose or throat, but these cases are rare.
Who’s at risk? And can melanoma be prevented?
Melanoma is thought to be caused by a mix of genetic and environmental factors. One of the leading hazards is exposure to ultraviolet light, including from the sun and indoor tanning.
A history of severe, blistering sunburns can raise your risk; as can living close to the equator or at a high elevation, where the sun’s rays are more intense.
The best way to reduce your risk is to avoid unnecessary exposure to UV light. The sun’s rays are strongest between 10am and 4pm, so limit your time outside during those hours. Wear protective clothing and eyewear and regularly apply sunscreen of at least SPF 30.
Dr Shanthi Sivendran, a medical oncologist and senior vice-president at the American Cancer Society, also warned against using tanning lamps and beds, which significantly increase melanoma risk.
A number of states have barred minors from using tanning beds, in part because of this concern, according to the Skin Cancer Foundation. Federal regulators had also proposed banning them for minors, but the Food and Drug Administration recently withdrew that proposal.
People with lighter skin are more vulnerable to damage from UV light. But Sivendran said that does not mean those with darker skin should not also remain vigilant.
“You can get melanoma regardless of what your skin colour is,” she said.
It’s also important to know if melanoma runs in your family, which can heighten your risk. And people with compromised immune systems are also more likely to develop melanoma.
While about half of cases occur in people aged 66 and over, younger people can also develop melanoma.
How can I detect melanoma?
Spotting melanoma early is vital, because nearly all cases that have not spread to other parts of the body are curable. However once the disease reaches the lymph nodes or more distant organs, five-year survival rates decrease significantly.
There are no standard guidelines for skin cancer screening, but clinicians can examine your skin for abnormalities during annual checkups.
Dr Kelly Nelson, a dermatologist at the MD Anderson Cancer Center, also recommended that patients conduct their own regular head-to-toe self exams.
To recognise changes in your skin, it’s helpful to be familiar with it, Nelson said.
“People who are more aware of what the skin on their backs looks like are less likely to die of melanoma than people who have no clue at all.
“It’s this fine line of balancing between having some degree of skin awareness, but also not being worried that every mole on your body is a ticking time bomb.”
To distinguish melanomas from ordinary moles or irritations, dermatologists suggest checking for the “ABCDEs”: spots that have an asymmetrical shape, a notched or scalloped border, an unusual color pattern, a diameter larger than 6mm, or a spot that has evolved over time.
How is melanoma treated?
For cancers that have not spread, a doctor will likely cut out the growth along with a margin of surrounding skin. They also may conduct a biopsy of nearby lymph nodes to assess the risk of the cancer spreading and help the doctor decide if further treatment is needed.
While melanoma is more likely to be deadly if it reaches distant parts of the body, major advances in treatment have improved the outlook, even for those who didn’t catch their cancer early.
These include treatments that harness the immune system to fight tumours, and targeted therapies that directly attack cancer cells.
In 2024, the FDA approved the first cancer treatment using tumor-infiltrating lymphocytes, known as TIL therapy, for use against melanomas that have not responded to other treatments.
The personalised vaccine developed by Merck and Moderna is tailored to the specific genetic makeup of a patient’s cancer.
It was tested in combination with Keytruda, an immunotherapy drug used to treat many types of cancer, including melanoma.
The companies have yet to release detailed results, but said Wednesday that those who received the vaccine along with Keytruda had a lower risk of recurrence or spread than those who received Keytruda alone.
Merck and Moderna said that full data on the treatment would be shared with regulators and presented at an upcoming medical conference. NYTIMES
This article originally appeared in The New York Times.