Skin Cancer Prevention

After a long, cold and snowy winter, most of us are ready to get out in the warm weather! While it’s great to have the sun shining once again, experts at Newton-Wellesley want you to know how to keep your skin healthy all year long. Protecting your skin from sun exposure is the key to preventing the most common form of cancer – skin cancer.

Skin Cancer Defined
“Skin cancer is the abnormal growth of skin cells that most often develops on skin exposed to the sun,” says Francis Renna, MD, Chief of Dermatology at Newton-Wellesley Hospital. “While these areas are the most common for skin cancer to occur, it is important for people to understand that this form of cancer can also occur on areas of your skin not ordinarily exposed to sunlight.”

Skin cancer occurs when mutations form from the DNA of healthy skin cells. These mutations cause the cells to grow out of control and form a mass of cancer cells. The cancer begins in the top layer of skin, called the epidermis – a thin layer that provides a protective cover for the skin cells that your body continually sheds. Much of the damage to the DNA in skin cells results from ultraviolet (UV) radiation found in sunlight and in commercial tanning lamps and tanning beds. However, skin cancers can also develop on skin not usually exposed to sunlight and affect people of all skin tones, including those with darker complexions.

“Most skin cancers develop on sun-exposed areas including the scalp, face, lips, ears, neck, chest, arms, hands and legs,” says Dr. Renna. “But it can also form on areas that rarely see the light of day, which makes thorough skin evaluations an important component to prevention.”

Also people whose immune system is compromised from illness, such as leukemia, or from immunosuppressive medications for certain illnesses or following organ transplantation have an increased risk for skin cancer and need to have regular complete skin examinations and self-skin examinations.

Three Types of Skin Cancer
The three major types of skin cancer include – basal cell carcinoma, squamous cell carcinoma and melanoma.

Basal cell carcinoma is the most common form of skin cancer. These cancers almost never spread to other parts of the body. Basal cell carcinoma usually occurs in sun-exposed areas of the body and appears as a shiny, raised growth that may have red lines or as a scabby sore that does not heal.

Squamous cell carcinoma also occurs most often on sun-exposed areas and presents as a raised growth with a hard center. People with light-colored skin and a history of sun exposure have a greater risk of developing this type of cancer.

Melanoma is less common, but more dangerous as it can spread internally. Melanoma affects people of any skin tone and can develop anywhere on your body, in otherwise normal skin or in an existing mole that becomes cancerous. Rarely, melanoma can also occur in the eye, mouth and other mucous membranes.

“When diagnosed early, melanoma has a very high cure rate,” says Dr. Renna. “It is important to be aware of the visible danger signs, which include any growth with different shades of color – with or without black. It is also important to look for any irregular shape or surface.”

Skin Cancer Risk Factors
There are a variety of factors that can make you more at risk of skin cancer, including:

  • Fair skin: Any skin color is at risk for skin cancer; however, having less pigment provides less protection from damaging UV radiation.
  • History of sunburns: Sunburns damage your skin cells and increase your risk of skin cancer.
  • Excessive sun exposure: Spending considerable time in the sun increases your skin cancer risk. Tanning, including exposure to tanning lamps and beds, also puts you at risk.
  • Sunny or high-altitude climates: People who live in sunny, warm climates are exposed to more sunlight than people who live in colder climates. Living at higher elevations, where sunlight is the strongest, also exposes you to more radiation.
  • Moles: People with a large number of moles or irregular appearing moles are at increased risk of skin cancer.
  • Family history of skin cancer: If an immediate family member has had skin cancer, you may have an increased risk and you should have a complete skin examination.
  • Increasing age: Skin cancer risk increases with age, primarily because many skin cancers develop slowly. The damage that occurs during childhood or adolescence may not become apparent until middle age.

Early Detection is Key
Early detection and diagnosis is the most important factor in curing skin cancer.

“If you have a growth or mole that is changing in any way – growing in diameter, elevation or color – or if it’s a new growth, you should consult your primary care physician or your dermatologist,” says Dr. Renna. “It is also common not to have any symptoms. Many people think it has to itch, burn or sting, but that is not the case. It is important to have the growth examined within several weeks and have a complete skin exam to check for any other suspicious growths.”

If the growth looks worrisome, patients are referred to a dermatologist for a biopsy, where either a small sample of the suspicious-looking skin or the entire growth, depending on its size and location, will be sent for laboratory testing. A biopsy can determine whether you have skin cancer and, if so, what type of skin cancer you have.

“A growth suspicious for skin cancer is partially or completely removed, so it can be examined closely for a definitive diagnosis. Suspicious moles are usually completely removed,” explains Dr. Renna. “If the results determine it is cancerous, we remove the growth entirely. Melanomas require additional removal of the surrounding normal appearing skin. It is important for patients who have had skin cancer cells removed to continue to come in for yearly skin exams as well as conduct their own monthly self exams. After having skin cancer, your risk of having any of the three types increases.”

Also, the first-degree relatives (siblings, children or parents) of someone with melanoma or a melanoma-prone mole need to have a complete skin examination, since there may be a familial tendency for atypical moles and melanoma.

How to Check Your Skin
Dr. Renna encourages regular self evaluations over every square inch of skin – from the scalp to the toes. Self evaluations include examining your skin for new growths or changes in existing moles, freckles, bumps and birthmarks. With the help of mirrors:

  • Check your face, neck, ears and scalp.
  • Examine your chest and trunk, including under clothed areas and the tops and undersides of your arms and hands.
  • Examine both the front and back of your legs and your feet, including the soles and the spaces between your toes.

“With thorough self exams, the vast majority of skin cancers are caught at a curable stage,” says Dr. Renna. “The value of a careful surveillance program is crucial to early detection. Many people are reluctant to call their physician because they don’t want to be a bother. I encourage everyone to call immediately. This is the only way we can diagnose dangerous growths at a curable point.”

Sun Protection
According to Dr. Renna, the most important tool in preventing skin cancer is careful sun protection.

“We can’t change our genetic predisposition, but we can take important steps to protect our skin from the sun,” says Dr. Renna. “People with all skin types – from those that burn easily to those that rarely burn – need to protect themselves from the sun. Any time you are in the sun, even without burning, damage to your skin is taking place. Any unprotected sun exposure increases skin cancer risk for a lifetime.”

Sun protection involves using sunscreen and clothing as well as avoiding the sun when it is most intense from 10:00 am to 3:00 pm.

You absorb UV radiation year-round, and clouds offer little protection from these damaging rays. A comprehensive sun protection plan also includes avoiding tanning beds and wearing UV-blocking sunglasses. In addition to skin cancer, unprotected exposure also causes accelerated aging such as wrinkles, uneven skin color, brown spots and sagging skin.

“Sunscreen is very important to use, but it does not provide full protection from the sun,” adds Dr. Renna. “I advise people to wear hats, long sleeve shirts and pants when they are in the sun to further protect their skin.”

Sunscreen Options
Because some of the ultraviolet light that causes skin cancer can pass through window glass, it is important to use a broad spectrum sunscreen. The ingredients in the sunscreen should include one of the following: avobenzone (also known as parsol), zinc oxide or titanium dioxide. Sunscreen was initially developed to prevent skin from burning; however, it is now an important tool in preventing skin cancer and aging.

“Using sunscreen with one of these three ingredients is just as important as the number of the sunscreen,” says Dr. Renna. “I recommend using a minimum of 30 SPF. There can be some confusion about what these numbers mean. The number indicates the amount of time you can be in the sun before you burn. For example, an SPF of 30 means you can be in the sun 30 times as long before burning.”

Dr. Renna’s tips for applying sunscreen include:

  • Apply sunscreen at least half an hour before sun exposure.
  • Apply to dry, not wet or damp skin.
  • Reapply every two to three hours and after swimming.
  • For brief, daily sun exposure, use a moisturizer with sunscreen.
  • Remember to apply to sensitive areas like scalp, face, ears and neck. Scalp protection is especially important for those with thinning hair.

After age six months, it is also important to apply sunscreen to children and rely on protective clothing to prevent sun exposure.

“We want people to enjoy spending time outdoors and taking part in activities they enjoy,” says Dr. Renna. “We hope to create awareness for the dangers of sun exposure in causing skin cancer and aging skin and help people understand how to protect their skin. Through proper sun protection and regular skin exams, we can help our patients prevent skin cancer – and treat those cases that we catch at an early stage.”

More Information
For more information about Dermatology at Newton-Wellesley Hospital, call CareFinder at 1-866-NWH-DOCS (694-3627) or visit For information on cancer screening and treatment, visit our Vernon Cancer Center and Auerbach Breast Center.

Francis Renna, MD, Chief of Dermatology,
Newton-Wellesley Hospital

Dr. Renna is board certified in dermatology. He received his medical degree from Tufts University School of Medicine and completed his residency at Massachusetts General Hospital. Dr. Renna is also a clinical professor of dermatology at Tufts University School of Medicine.

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