Be "sun smart" to avoid skin cancer

The Bottom Line

  • The most common cause of all skin cancers is exposure to ultraviolent radiation (UVR), of which the sun is the main source.

  • People can get skin cancer at any age. There has been a significant increase in melanoma diagnoses in the past 25 years.

  • Screening and other measures to detect skin cancer early do not appear to improve mortality rates.

  • Don't let down your guard! Make sure your skin is always adequately shielded.

Oh sunny, sunny days... Many would agree that there truly is nothing better than relaxing outdoors, perhaps soaking up a few of those golden rays. But like most of the things we enjoy in life, moderation is the key and that's especially true when it comes to sun exposure.

Skin cancer affects people of all ages and the main cause is exposure to ultraviolet radiation (UVR), primarily from the sun although tanning beds are another source (1;2). The most common type of skin cancer is basal cell carcinoma, followed by squamous cell carcinoma (1). Both of these "non-melanoma" types of cancer tend to grow slow and rarely metastasize (spread to other parts of the body), unlike melanoma (1). Melanoma is being diagnosed more frequently in both men and women (3).

Can some deaths be prevented with screening and surveillance to detect cancer at the earliest stages? That's the subject of ongoing research but so far, the evidence isn't encouraging: one study found that screening programs had only a very small effect on the number of deaths due to skin cancer (4).

How to practice safe sun

So while people are still urged to have any unusual moles and growths checked, prevention remains the key to reducing skin cancer risk. Here are ways to keep a safe and respectable distance from the sun's powerful rays (5-9):

  • Check the UV index on a daily basis, so you're aware of the strength of the sun’s rays. If it's a three or higher, take extra care to protect your skin (6).

  • Limit the time you spend in the sun or avoid it altogether during the middle of the day (between 11 a.m. and 3 p.m.), when the UV index tends to be higher in Canada (5;6).

  • Cover up. Wear a hat, sunglasses and clothing designed to protect you from the sun's rays. Staying in the shade and covering up are more effective than sunscreen for reducing cancer risk (7).

  • If you have to be exposed to the sun, use a water-resistant, broad spectrum sunscreen with a sun protection factor (SPF) of at least 30 and reapply frequently (5;6).

  • Be particularly vigilant when you’re in or near water, sand or snow as they reflect the sun's rays (5).

  • Don't assume you're safe when the temperature is low, the sun isn't out in full force or there's a cooling breeze: you don't have to be feeling the heat to suffer sunburn and skin damage (5)!

  • Avoid use of tanning beds; studies show that tanning bed use increases your risk of melanoma by 16% (8;9).

A deep tan may look attractive in the short term, but we know it's a sign of skin damage and a warning sign we need to heed if we want to avoid skin cancer.

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Author Details


  1. Linares MA, Zakaria A, Nizran P. Skin cancer. Prim Care. 2015; 42(4):645-659. doi: 10.1016/j.pop.2015.07.006

  2. International Agency for Research on Cancer. IARC monographs on the evaluation of carcinogenic risks to humans. Lyon (FR): International Agency for Research on Cancer; 2012. 100D vol. Available form: http://monographs.iarc.fr/ENG/Monographs/vol100D/mono100D.pdf

  3. Canadian Cancer Society’s Advisory Committee on Cancer Statistics. Canadian Cancer Statistics 2017. Toronto (ON): Canadian Cancer Society; 2017. 142 p. Available from: http://www.cancer.ca/~/media/cancer.ca/CW/cancer%20information/cancer%20101/Canadian%20cancer%20statistics/Canadian-Cancer-Statistics-2017-EN.pdf?la=en

  4. Wernli KJ, Henrikson NB, Morrison CC et al. Screening for skin cancer in adults: updated evidence report and systematic review for the US Preventive Services Task Force. JAMA. 2016; 316(4):436-447. doi:10.1001/jama.2016.5415.

  5. World Health Organization, International Agency for Research on Cancer. IARC Handbooks of Cancer Prevention: sunscreens. Lyon (FR): World Health Organization & International Agency for Research on Cancer; 2001. 5 vol. Available from: http://publications.iarc.fr/Book-And-Report-Series/Iarc-Handbooks-Of-Cancer-Prevention/Sunscreens-2001

  6. Marrett LD, Chu MB, Atkinson J, et al. An update to the recommended core content for sun safety messages for public education in Canada: A consensus report. Can J Public Health. 2016; 107(4-5):e473-e9.   

  7. Linos E, Keiser E, Fu T et al. Hat, shade, long sleeves, or sunscreen? Rethinking US sun protection messages based on their relative effectiveness. Cancer Causes Control. 2011; 22(7):1067-1071. doi:10.1007/s10552-011-9780-1.

  8. Colantonio S, Bracken M, Beecker J. The association of indoor tanning and melanoma in adults: systematic review and meta-analysis. J Am Acad Dermatol. 2014; 70(5):847-857. doi: 10.1016/j.jaad.2013.11.050.

  9. Tierney P, Ferguson J, Ibbotson S et al. Nine out of 10 sunbeds in England emit ultraviolet radiation levels that exceed current safety limits. Br J Dermatol. 2013; 168(3):602-608. doi:10.1111/bjd.12181.

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