Skin cancer occurs when there is damage to cells that make up the outer layer of your skin, which causes these abnormal cells to grow in an uncontrolled way.
Skin cancer is the most common form of cancer—there are more cases of skin cancer than all other cancers combined. More than 5 million people in the United States are diagnosed with skin cancers each year. One in five people in the United States will develop a skin cancer by the age of 70. Most of these cancers are caught before they spread, and they are treated with surgical removal in the doctor’s office.
About 200,000 people are diagnosed each year with melanoma, a type of skin cancer that develops when melanocytes (the cells that give the skin its tan or brown color) start to grow out of control. Melanoma is a more dangerous form of skin cancer because it can spread to other parts of your body.
In this Q&A, Jesse M. Lewin, MD, FACMS, Associate Professor of Dermatology, Icahn School of Medicine at Mount Sinai, explains how skin cancer is best treated with early detection and treatment, and offers some tips for reducing your risks. Dr. Lewin is also Chief of Mohs Micrographic and Dermatologic Surgery and the Director of the Kimberly and Eric J. Waldman Melanoma and Skin Cancer Center.
“Unlike with many other cancers, patients and doctors have an advantage over skin cancer, in that we can see it with the naked eye,” says Dr. Lewin. “We don’t need imaging tests to look for these types of cancers; we just need to partner with our patients and be on the look-out for new and changing lesions, which are the earliest sign of skin cancer. The other advantage is our ability to reduce the risk of skin cancer by protecting ourselves from the sun and avoiding tanning beds.”
Who can get melanoma?
Melanoma affects more men than women. People of any skin type can get skin cancer, however those with lighter skin and eyes are at greater overall risk. Those at higher risk for developing melanoma include:
- People with more than 50 moles or with atypical moles, which are often larger and have more irregular borders (dysplastic nevi)
- People who are sensitive to the sun, which includes those who sunburn easily, or have natural blonde or red hair
- People with a personal or family history of melanoma
Is the risk different for people with darker skin tones?
While people with darker skin types have a lower chance of developing a skin cancer, these cancers do occur. In fact, melanoma in patients with darker skin tones is often diagnosed in its later stages, when it’s more difficult to treat. One reason is that people with darker skin types are more prone to developing skin cancer on nonexposed skin with less pigment. Up to 75 percent of tumors occur on the palms, soles, in the mouth, and under the nails.
What are the early signs of melanoma?
Some of the early signs include a new lesion that is irregular or an existing lesion which changes in size, shape, or color. We talk about the ABCDEs of melanoma: Asymetry; Border irregularity; Color variegation; Diameter greater than the size of a pencil eraser; and Evolving (changing). Between 20 and 30 percent of melanomas arise in association with existing moles, while 70 to 80 percent arise as new lesions.
Most melanomas are pigmented (brown or black). But some melanomas do not produce melanin and can appear pink or tan. This variety highlights the importance of seeing your dermatologist for periodic skin cancer screening exams and flagging lesions that are new or changing.
Melanoma can develop anywhere on your skin, but they are more likely to occur on the chest and back in men, and on the legs in women. The neck and face are other common sites. In about half of cases, patients discover these melanomas themselves. The best way to detect melanoma is to look for a change in the size, shape or color of an existing mole.
How can I avoid getting melanoma?
There are some risk factors that you cannot change like your skin type, age, and family history. But there are ways to lower your risk of skin cancer.
The majority of skin cancers are caused by ultraviolet (UV) radiation from the sun and tanning beds, so the most important thing you can do to reduce your risk of developing skin cancer is take steps to protect yourself from these exposures.
Studies show that having five or more sunburns doubles your risk for melanoma. This is why it is particularly important to educate and protect children and adolescents from the sun. People who first use a tanning bed before age 35 increase their risk for melanoma by 75 percent.
Here are some tips:
- Use sunscreen with a Sun Protection Factor (SPF) of 30 or above. A nickel-sized dollop of sunscreen is enough for your face. One ounce of sunscreen can cover your whole body but needs to be reapplied every two hours. One study found that regular daily use of an SPF 15 or higher sunscreen reduces the risk of developing melanoma by 50 percent. Your face is especially vulnerable to sun damage as it is exposed to the sun year-round.
- You are vulnerable to sunlight all year round, not just when at the beach. So, consider using a moisturizer with sunscreen every day all year.
- When outside, wear protective clothing, a wide brimmed hat, and UV-blocking sunglasses. Seek shade. If possible, avoid the sun during peak sun hours (10 am to 4 pm).
- Avoid tanning beds.
What Treatments are Available for Skin Cancer?
Mohs surgery is a precise surgical technique used to remove skin cancers, including those found in areas that cosmetically sensitive and functionally important: such as your eyelids, nose, lips, ears, fingers, and toes, as well as for some more aggressive skin cancers on other areas of your body. This procedure can be used to treat a wide array of skin cancers, including melanoma and nonmelanoma skin cancer.
For this procedure, we give local anesthesia to numb the skin, and then remove the skin cancer with a narrow margin of normal skin. The skin is then processed into slides so we can look under the microscope to check if the skin cancer has been fully removed. If there is still skin cancer left, we remove more skin and make more slides. Once the skin cancer is fully removed, we repair the wound by stitching it in a way to offer the patient an optimal functional and cosmetic outcome.
For early melanomas, removing the skin cancer with a margin of normal skin is all that is required. Mohs surgery with immunohistochemical staining for early melanomas, particularly those located on functionally and cosmetically sensitive areas, is also offered at select academic centers including Mount Sinai. For melanomas that are deeper, lymph node testing and imaging, such as a CT (computerized tomography) or PET (positron emission tomography), may be indicated. Those cancers are treated by medical and surgical oncologists.