Skin cancer and sun safety
by Aaron Peach and Mary Dickerson
The National Council on Skin Cancer Prevention has recognized SIU School of Medicine as a Skin Smart Campus.
A 2014 U.S. Surgeon General’s call to action to prevent skin cancer prompted the Indoor Tan-Free Skin Smart Campus Initiative, which drew a strong associations between indoor tanning use and skin cancer.
As a Skin Smart Campus, SIU School of Medicine supports public health efforts to inform the general public of skin cancer prevention strategies and to improve community access to sun protection materials. SIU is committed to skin cancer prevention and the ongoing health of its students and community. Its students and administration have pledged to keep indoor tanning devices off its campus and all affiliated buildings.
Skin cancer is the most common cancer diagnosed in the United States (1). Each year, more than 3 million Americans are diagnosed with non-melanoma skin cancer, such as basal cell carcinoma and squamous cell carcinoma (2). It is estimated that 1 in 5 Americans will develop skin cancer over the course of their lifetime (3). Many of these skin cancers can be disfiguring and even deadly—especially melanoma—due to their ability to grow and spread to other organs.
Melanoma rates in the U.S. have increased significantly over the past 40 years, doubling from 1982 to 2011 (4). Fortunately, the United States has begun to see a decline in melanoma in adolescents and young adults (ages 10-29 at time of diagnosis) (5). While we do not know the exact reason for this shift, the Centers for Disease Control and Prevention report a 10% decrease in the use of UV-emitting tanning beds among teenagers between 2009 and 2017 (6), which certainly supports the idea that abstaining from tanning beds contributes to a decreased risk of melanoma.
Since January 2014, Illinois has prohibited minors from using commercial tanning devices, even with parental permission. In 2012, local Springfield dermatologists─including faculty at SIU School of Medicine─attended a Springfield City Council meeting in full support of the minor indoor tanning ban. (More information about the meeting and the resulting legislation can be found at Illinois Times - Banning Tanning for Teens, IL General Assembly.)
Indoor tanning and its ultraviolet radiation exposure is associated with increased risk of developing melanoma, with the highest risk in people under 35 using indoor tanning devices (7, 8). Luckily, indoor tanning is completely preventable, which prompts us to raise awareness of this issue to reduce unnecessary illness and death in our community.
The three most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma and malignant melanoma. Basal cell carcinoma is the most common, with more than 3.6 million cases diagnosed in America each year. This type of cancer arises from basal cells at the bottom of the epidermis and may appear as a waxy, shiny bump on the skin. Squamous cell carcinoma is the second most common, with over 1.8 million cases diagnosed in America each year. This type of cancer arises from the outer layer, or epithelium, of the skin and may appear as a bump or red, scaly patch. Malignant melanoma is the most deadly form of skin cancer and is expected that over 200,000 cases will be diagnosed in America in 2021. This type of cancer arises from melanocytes, the pigment producing cells of the skin, and may be first noted as a new mole or change in the appearance of a preexisting mole. (9, 10)
Skin cancer occurs when mutations take place in the DNA of skin cells. These mutations allow the cells to grow and proliferate out of control, forming a mass of cells. These mutations are often acquired during a person’s lifetime either randomly or through exposure to a damaging agent, which is most often UV radiation. Less commonly, these mutations can be inherited through passing of certain genes which increase the risk of skin cancer. (10)
UV radiation can be divided into three main groups:
- UVA rays - These have the least energy among UV rays and make up about 95% of the UV rays that reach the ground. They penetrate skin the deepest, so they can damage proteins that give the skin structure, leading to premature skin aging changes like wrinkles. UVA rays can also indirectly contribute to skin cell DNA damage, playing a small role in skin cancer development.
- UVB rays - These have slightly more energy than UVA rays. UVB rays play a much larger role in developing skin cancer as they can damage the skin cell DNA directly. These make up about 5% of UV rays that reach the ground and are the main rays that cause sunburns.
- UVC rays - These have the most energy out of all the types of UV rays. Fortunately, they are absorbed by the ozone layer that sits high up in our atmosphere, so these rays do not reach our skin. Some devices can release UVC rays for the purpose of killing bacteria and other germs in water, air, or on surfaces.(11)
Skin cancer may be detected early by performing self-examination. During examination, it is important to keep the ABCDEs of melanoma in mind when evaluating spots or moles:
- A for asymmetry: one half of the mole is not like the other
- B for border: the mole has an irregular, poorly defined border
- C for color: the color of the mole varies from tan, brown or black to red, white, or blue
- D for diameter: the mole is 6 mm or greater (about the size of a pencil eraser)
- E for evolving: the appearance of the mole changes over time
If you notice any spots that are new or changing over time, different from others, or itching or bleeding, it is critical to make an appointment for evaluation by a board certified dermatologist. (13)
One of the most well-established risk factors for the development of skin cancer is UV radiation, which can come from sun exposure or tanning beds. Thus, having a history of sunburns, living in a sunny climate, or excessive exposure to sun or tanning beds are all associated with increased risk. Other risk factors include having fair skin, having a personal or family history of skin cancers, having a weakened immune system, and exposure to certain toxic substances. (10)
While some risk factors such as race and family history cannot be controlled, there are steps you can take to reduce your risk of developing skin cancer. One of the most important steps is to reduce your exposure to UV radiation. This can be achieved through:
- Limiting time in direct sun exposure
- Wearing protective clothing when exposed to the sun
- Wearing a good sunscreen product daily and reapplying every 2 hours (SPF30+ and broad spectrum)
- Avoiding the use of tanning beds (12)
It is important to look for a sunscreen with broad spectrum coverage, meaning it protects against UVA and UVB rays. SPF determines how effective the sunscreen is against preventing a sunburn by UVB rays. Most experts recommend an SPF of at least 30 for everyday use. For swimming or exercising outdoors, a water-resistant sunscreen option may be preferred to prevent washing off. (14)
- U.S. Department of Health and Human Services. Skin Cancer: Quick Facts from the Surgeon General. Updated August 8, 2014. Accessed July 8, 2021 from https://www.hhs.gov/surgeongeneral/reports-and-publications/skin-cancer/index.html
- Rogers HW, Weinstock MA, Feldman SR, Coldiron BM. Incidence estimate of nonmelanoma skin cancer (keratinocyte carcinomas) in the US population, 2012. JAMA Dermatol 2015; 151(10):1081-1086.
- Stern RS. Prevalence of a history of skin cancer in 2007: results of an incidence-based model. Arch Dermatol. 2010;146(3):279-82.
- Guy GP, Thomas CC, Thompson T, Watson M, Massetti GM, Richardson LC. Vital signs: Melanoma incidence and mortality trends and projections—United States, 1982–2030. MMWR Morb Mortal Wkly Rep. 2015;64(21):591-596.
- Paulson KG, Dupta D, Kim TS, et al. Age-specific incidence of melanoma in the United States. JAMA Dermatol. 2020;156(1):57-64
- Centers for Disease Control and Prevention. Skin Cancer: Indoor tanning. Updated October 31, 2018. Accessed July 8, 2021 from https://www.cdc.gov/cancer/skin/statistics/index.htm?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fcancer%2Fskin%2Fstatistics%2Fbehavior%2Findoor-tanning.htm
- Colantonio S, Bracken MB, Beecker J. The association of indoor tanning and melanoma in adults: systematic review and meta-analysis. J Am Acad Dermatol. 2014;70(5):847-57.e1, 18.
- Boniol M, Autier P, Boyle P, Gandini S. Cutaneous melanoma attributable to sunbed use: systematic review and meta-analysis. BMJ. 2012;345:e4757.
- Skin Cancer Foundation. Skin Cancer Facts and Statistics. Updated January 13, 2021. Accessed July 8, 2021 from https://www.skincancer.org/skin-cancer-information/skin-cancer-facts/
- Mayo Clinic. Skin Cancer. Updated December 5, 2020. Accessed July 8, 2021 from https://www.mayoclinic.org/diseases-conditions/skin-cancer/symptoms-causes/syc-20377605
- American Cancer Society. Ultraviolet (UV) Radiation. Updated July 10, 2019. Accessed July 8, 2021 from cancer.org/cancer/cancer-causes/radiation-exposure/uv-radiation.html
- American Cancer Society. Can Melanoma Skin Cancer Be Prevented? Updated August 14, 2019. Accessed July 8, 2021 from https://www.cancer.org/cancer/melanoma-skin-cancer/causes-risks-prevention/prevention.html
- American Academy of Dermatology Association. What to Look For: ABCDEs of Melanoma. Updated 2021. Accessed July 8, 2021 from https://www.aad.org/public/diseases/skin-cancer/find/at-risk/abcdes
- American Academy of Dermatology Association. How to Select a Sunscreen. Updated 2021. Accessed July 8, 2021 from https://www.aad.org/public/everyday-care/sun-protection/sunscreen/how-to-select-sunscreen