Hooman Khorasani, MD
Chief, Division of Dermatologic and Cosmetic Surgery
Icahn School of Medicine at Mount Sinai
Minimizing Your Risk of Melanoma — the Deadliest Form of Skin Cancer
From picnics in the park to backyard barbecues, from swimming to sailing, activities under the sun bring joy and a sense of freedom. Unfortunately, they can also expose you to excessive ultraviolet (UV) rays, a major cause of melanoma, the most dangerous type of skin cancer.
Melanoma incidence rates among Americans are increasing rapidly, in part due to our love of the outdoors and tanning, whether on a beach or in a booth. According to the American Cancer Society, melanoma accounts for only about one percent of skin cancer cases, yet causes the vast majority of deaths, killing more than 10,000 people each year.
Here’s what you need to know about this potentially deadly disease, and what you can do to prevent it — or treat it early, when it is still highly curable.
What Causes Melanoma
Melanoma originates in cells called melanocytes, which protect our skin against the sun’s harmful UV rays. It results from cellular gene changes that can be inherited and/or caused by UV radiation. The mutated melanocytes may start to grow abnormally, causing cancer to develop in a pre-existing mole or as a new mole.
Why Early Detection Is So Important
The skin has three layers: the top layer is the epidermis, the middle is the dermis, and the bottom is subcutaneous fat. When melanoma is detected and treated with surgical excision at its earliest stage — when it has invaded only the epidermis — almost all patients survive. However, if the cancer is not caught before it spreads deeper into the dermis, the chance of metastasis (spreading to other parts of the body) increases significantly. Even with recent treatment advances, metastatic melanoma typically causes death within 6 to 12 months.
Who Is at Risk
Anyone can get melanoma, but people at increased risk include those with:
• A genetic predisposition, including people with red or blond hair, blue eyes, and fair skin that freckles easily.
• A personal history of melanoma, or a family history of it in a parent, sibling, or child.
• A large number of moles. (Having 11 or more moles on one arm usually indicates you have enough moles throughout your body to put you at increased risk.)
• A history of dysplastic nevi. These are usually atypical moles and potentially precancerous lesions that may resemble melanoma and, when biopsied, look different from common moles under a microscope. Your dermatologist can tell you if you have any dysplastic nevi.
• A history of UV radiation exposure from the sun or artificial sources, such as tanning beds.
Melanoma usually occurs due to multiple risk factors. For instance, a genetic predisposition can be considered a first “hit,” but further gene changes are typically required for cancer to arise. A second hit, like a blistering childhood sunburn, and then a third hit, such as another severe sunburn as an adult, could damage the cells’ DNA beyond repair, causing melanoma to develop.
Tips for Preventing Melanoma
The one risk factor you can control is exposure to UV radiation. To protect yourself:
Limit sun exposure. Avoid being out in the sun when UV light is at its strongest, generally from 10 am to 2 pm.
Wear protective clothing outdoors, such as a long-sleeved shirt, long pants, and broad-brimmed hat. For the beach or pool, swim shirts made with special UV-protective fabric are available for both children and adults.
Use sunscreen regularly. The most important factor in choosing a sunscreen is not the brand or SPF, but rather whether you are likely to use it regularly. Does it rub in easily? Do you like the smell? Many sunscreens that feel like regular moisturizers are now available.
Note that an SPF of 30 is sufficient; high numbers, like SPF 100 or 120, are mere marketing gimmicks that give a false sense of security. No matter their SPF value, all sunscreens should be reapplied regularly: every half hour when engaging in strenuous outdoor activities, like beach volleyball or bike riding; every two hours when outside going about daily activities, such as shopping or running errands; and immediately after swimming. And be sure to use enough — one ounce, or about enough to fill a shot glass, is a good amount for a normal-size person.
Avoid tanning beds.
The Best Way to Spot Melanoma Early
Melanoma can develop anywhere you have skin or mucous membranes, not just where the sun shines: scalp, chest, arms, legs, soles of your feet, nail beds, fingertips, inside the eye, lips, cheeks, labia, underarms, and more. Examining your body from head to toe once a month (by yourself or with a partner) is the best method of early detection. Multiple mobile apps are now available to help you check your skin and track moles over time with photographs.
Look for moles showing any of the “A, B, C, D, E” warning signs of melanoma:
A = asymmetry. If you draw an imaginary line through the center of a mole, the shape of its right half does not match its left.
B = border. The mole’s border is irregular or ragged rather than smooth.
C = color. The color is not uniform. For instance, a mole may have extra pigmentation in the center, or be a variety of colors.
D = diameter. The mole is larger than 6mm in diameter, about the size of a pencil eraser.
E = evolving. Most important to recognize is a mole that has changed in any way; e.g., it has grown darker or bigger, suddenly started to bleed, or just looks different than it used to.
If you see any of these warning signs, visit a board certified dermatologist right away. Your doctor may recommend a biopsy, which takes only a few minutes and involves injecting the mole with local anesthesia and shaving it off. Lab results are usually returned within a few days.
Don’t Forget Annual Skin Checks
Finally, be sure to get your skin thoroughly examined once a year by a board certified dermatologist. Melanoma can start anywhere, even in areas never exposed to the sun, so choose a doctor in front of whom you are comfortable removing all clothing and jewelry.
In places where patients have limited access to specialty care, high-definition cameras and videos can now transmit images for examination by a distant dermatologist. Patients without insurance may be able to find free skin cancer screenings — usually in the spring — by checking with local hospitals or the American Academy of Dermatology’s website.