It’s the most commonly occurring cancer in the United States, accounting for nearly half of all diagnosed cancers. It is found on the body’s largest organ and affects about twice as many men as women. According to the American Academy of Dermatology, one in five Americans will develop some form of this cancer during their lifetime, even though it is highly preventable.
The disease in question? Skin cancer.
There are a number of different types of skin cancers, but they are grouped into two categories: melanoma and nonmelanoma.
Melanoma
Melanoma is less common than nonmelanoma, it accounts for only about three percent of all skin cancers, but it is also more serious. This type of cancer starts in the pigment producing cells on the skin – typically on moles, birthmarks or freckles. The cells become abnormal, grow uncontrollably and invade surrounding tissues. In its first stages, melanoma affects only the skin. As the cancer progresses, it may spread through the blood or lymph system to other organs and bones.
Usually one of the first signs of melanoma is a change to a mole or other skin growth. Melanoma can develop in an existing mole, but it can also develop on previously unmarked skin. A melanoma usually looks like a brown or black mole that is asymmetrical, with uneven borders. It may be lumpy or rounded, change color, become crusty, ooze or bleed. In later stages of the disease there may be pain in the mole or lesion.
The American Cancer Society gives the ABCD’s of assessing moles and skin changes. A is for asymmetry, meaning one half of the mole doesn’t match the other half. B is for border irregularity with edges that are uneven and ragged. C is for color. Different shades of tan, brown and black exist within the same mole. The mole may appear mottled. D is for diameter. Any increase in diameter should be cause for concern. Also, moles that are larger than the size of a pencil eraser (6 mm) might be early signs of melanoma.
The most common places for melanoma to develop are on the upper back of men and women and on the legs in women.
Nonmelanoma
Two types of nonmelanoma cancers, called basal cell carcinoma and squamous cell carcinoma, are the most common forms of skin cancer. Basal cell, which is three times more common than squamous cell, starts on the skin and can damage deeper tissues, such as muscles and bones, but it rarely spreads to other parts of the body. Squamous cell often begins growing in skin that has been injured or diseased.
The most common place for basal cell to appear is on the nose. Other locations typically affected are the head, neck, back, chest and shoulders. Symptoms of basal cell can vary greatly, but always include changes to the skin such as: tender red spot that bleeds easily, a scarlike patch of skin that is firm to the touch, a bump that itches, bleeds, crusts over and doesn’t heal within three weeks, a firm, pearly bump with tiny spider-like blood vessels or a change in the size, shape or color of a wart or mole.
Squamous cell carcinoma typically affects the face, head and neck. Like basal cell, symptoms can vary, but involve changes in irregularities with the skin including: a firm red bump on sun-exposed skin, a wart-like skin growth, thickened skin on the lower lip or a sore that doesn’t heal on the lip.
Causes
Both melanoma and nonmelanoma are caused by overexposure to the sun and ultra violet (UV) radiation from the sun. In addition, other risk factors, such as family or personal history of skin cancer, childhood sunburns and blistering, use of tanning beds, extensive time spent working outdoors and having fair skin, blond or red hair or blue eyes are associated with all types of skin cancer.
Number and type of moles on the body also can indicate a propensity for melanoma. Atypical moles, having 50 or more moles and having moles present at birth, especially if they are larger than 20 cm are all risk factors for melanoma.
Prevention
The most important line of defense against skin cancer involves protecting your skin from the sun and other sources of UV light such as tanning beds. Limit your exposure to the sun, especially between 10:00 am and 4:00 pm. Seek shade. Choose a shady spot over a sunny one. Cover up. Wear a long-sleeved shirt and a wide-brimmed hat. Wear sunglasses with UV protection. Use sunscreen correctly. Choose a sunscreen with “broad spectrum” protection and an SPF of at least 15. Apply it liberally at least 20 minutes before you go outside. Reapply every two hours, and more often if you are in the water. Use sunscreen even on cloudy or hazy days. Use a lip balm with the same SPF. BE especially careful about following these preventative measures with children.
In Minnesota, it seems we wait all winter long for the warm rays of the summer sun. As inviting as the sunshine might seem, there are dangers associated with it. But, that doesn’t mean you have to be sentenced to a life indoors this year. By using sunscreen correctly and scheduling your outdoor activities around the middle hours of the day, you can enjoy the summer in all its glory, and protect yourself from skin cancer at the same time.
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By: James Rogers, M.D.