Living a Mile High––What You Should Know About Skin Cancer and Your Risk
By Melissa France, Denver LIVING WELL Magazine
You live in one of the sunniest locations in the United States, where year round the sun is shining during daylight hours more than 70% of the time. This is an amazing gift for active Coloradans who enjoy spending time outdoors. However, this gift comes with risk. Sun damage and skin cancer are very real concerns in the Mile High City.
Your risk of developing skin cancer is determined by a combination of where you live, who you are and what you like to do. Our altitude here in Denver is officially a mile above sea level as measured from the steps of the state capitol building. Living at this high elevation, where sunlight is almost constant, makes UV exposure a year-round concern. At higher altitudes the atmosphere is thinner and therefore absorbs less UV radiation. Most skin cancers are caused by exposure to ultraviolet rays that make it through the ozone layer and to the earth’s surface.
The UV Index, provided by the National Weather Service, offers a daily forecast of the expected risk of overexposure to the sun using UV intensity levels on a scale of one to 11+. A rating of one indicates a low risk of overexposure and a rating of 11+ signifies an extreme risk. Denver routinely reaches or exceeds moderate levels, often landing in the extreme category during UV season, which is March 1 through October 31. Studies have shown that with every 1,000 meters of altitude over sea level, UV radiation levels increase by about 10%. Our risk of skin cancer also increases as ozone levels are depleted, reducing the natural protective filter from UV radiation reaching the Earth’s surface.
Skin cancer is the most common form of cancer in the United States. According to Skin Cancer Foundation Statistics, the incidence of both non-melanoma and melanoma skin cancers has been increasing over the past four decades. Currently, between two and three million non-melanoma skin cancers and 132,000 melanoma skin cancers occur globally each year. One in every three cancers diagnosed is a skin cancer and one in every five Americans will develop some type of skin cancer in their lifetime.
Even though the environment plays a key role in the global incidence of skin cancers and melanoma, the main factors appear to be both genetic and connected with recreational exposure to the sun and a history of sunburn. It is widely accepted in 2013 that the significant increases in the number of cases of all types of skin cancers, particularly in the boomer generation, is the result of a lifetime of enjoying the sun without UV protection.
According to Dr. John Burke, MD., a medical oncologist with Rocky Mountain Cancer Centers, “The incidence of melanoma is increasing dramatically. In 1965 an individual’s lifetime risk for developing melanoma was about one in 600. By 1985 the lifetime risk had increased to about one in 150. Today it is estimated that one in 37 men and one in 56 women in the U.S. will develop melanoma during their lifetime. The reasons for this dramatic increase in the lifetime risk in melanoma are not entirely clear, but increased recreational sun exposure likely has a role. An increase in the number of skin cancer screenings allowing for early detection may also play a small part.”
People who have a close relative (parent, sibling, or child) with melanoma may also be at greater risk of developing the disease than the general population. There are other genetic factors that attribute to your risk, including your skin tone, eye color and susceptibility to sunburns. Generally, if you are fair skinned with light hair and light eyes, you are at a higher risk than individuals with darker skin tones. Sun damage can be cumulative, meaning that a small dose every day, week, or even summer can accumulate over time making your risk even higher later in life.
Dr. Burke adds “Non-melanoma skin cancers (like basal cell carcinomas and squamous cell carcinomas) are associated with lifetime, cumulative sun exposure. In contrast, melanomas tend to be related to intermittent, intense exposure (sunburns). High levels of cumulative sun exposure in the 50+ age group may predispose this age group to non-melanoma skin cancer.”
There are 3 main types of skin cancer:
Basal cell carcinoma is the most common form of skin cancer with over two million diagnosed annually in the U.S. BCCs usually appear as a slowly growing, non-healing sore that often has a pearly raised border. They are rarely fatal, but can be highly disfiguring if allowed to grow.
Squamous cell carcinoma is the second most common form of skin cancer with an estimated 700,000 cases of SCC diagnosed each year in the U.S. As with basal cell, SCCs usually appear as slowly growing, non-healing sores but have a harder thickened scale.
Malignant melanoma is the deadliest form of skin cancer. Melanoma accounts for less than 5% of skin cancer cases, but the vast majority of skin cancer deaths. It often appears as a pigmented lesion with irregular borders and irregular pigmentation. According to research from the National Cancer Institute in 2012, the majority of people diagnosed with melanoma are white men over age 50. Caucasian men over age 65 have had a 5.1% annual increase in melanoma incidence since 1975, the highest annual increase of any gender or age group.
Early diagnosis is your best option if the sun damage is already done. Know your body, so you can recognize changes and possible melanomas. Patients themselves first identify half of melanomas. The American Academy of Dermatology recommends an annual full body exam to allow early detection of treatment. An important part of prevention is mole tracking with the ABCDE danger signs: A=asymmetry, B=irregular border, C=irregular color, D=increase in diameter, E=evolution or changes in the mole. A Body Mole Map is available through the American Academy of Dermatology website.
“Only about one third of the population performs self-exams for the signs of skin cancer and a significant number of those people are unable to see or recognize suspicious lesions on their own. A visit to your dermatologist is important for a thorough evaluation of any areas of concern,” suggests Dr. Richard Asarch, MD, of the Asarch Center for Dermatology and Laser in Denver.
If you are diagnosed with basal cell and squamous cell skin cancers, Mohs Micrographic Surgery is the most effective method for treatment. With a 99% success rate, Mohs allows surgeons to identify and remove tumors one layer at a time while preserving as much healthy tissue as possible.
According to Dr. Asarch, “For invasive types of melanoma, there is still some controversy about utilizing the Mohs micrographic technique versus removal with wide margins. When sparing as much tissue as possible is important, such as when working on areas on the face, the Mohs procedure can be used. This is particularly possible when the type of melanoma is in a very early stage, e.g., lentigo maligna melanoma.”
Regardless of what stage of life you are in or what level of damage you have accumulated, it is essential to protect yourself when you are out in the Colorado sun. The American Academy of Dermatology recommends applying a broad-spectrum sunblock with an SPF of at least 30 about 15 to 20 minutes before exposure. Remember to re-apply every couple of hours, especially if you are swimming or sweating. Try to avoid sun exposure between 10 a.m. and 3 p.m. when the sun’s rays are the strongest and protect your head and face with a wide-brimmed hat and sunglasses whenever possible.
You can learn more about the dermatologists quoted in this article by visiting their websites below.
Dr. Richard Asarch, MD asarchcenter.com
Dr. John Burke, MD rockymountaincancercenters.com/rmcc-difference/our-doctors/burke