Highlights
- Skin cancer incidence continues to increase, especially in adults age 50 and older.
- In 2016, adults age 50 and older accounted for over 80% of all skin cancer cases.
- Much of the increase in skin cancer is due to exposure to ultraviolet radiation (UVR).
- Local municipalities should promote and implement policies and programs, including strong shade policies, to reduce exposure from solar UVR and tanning beds.
Incidence trends
Skin cancer has been increasing in older adults in Ontario since the early 1990s. From 1991 to 2016, the incidence rates of skin cancers in Ontario increased by 2.3% per year for people ages 50 to 74 and by 4.6% per year for those age 75 and older. For people ages 30 to 49, incidence also increased by 0.6% per year, but for people younger than age 30, it remained stable.
Melanoma and other non-melanoma skin cancers from the Ontario Cancer Registry were analyzed for this Cancer Fact. However, basal and squamous cell carcinomas of the skin were not included because they are not collected in the Ontario Cancer Registry.
Ultraviolet radiation (UVR)
Ultraviolet radiation (UVR) is an established cause of skin cancer[1] and most skin cancers are caused by exposure to UVR from the sun or other sources, such as tanning beds.[2] Exposure to UVR can have additional serious effects on human health, such as premature skin damage, cancer of the eye, cataracts and increased susceptibility to infections.[3]
The increase in skin cancers seen since the early 1990s may be related to an increase in sun exposure. National surveys conducted in 1996 and 2006 found that Canadians spent more time in the sun, such as through more time outdoors and vacations in sunny climates without increasing their sun protection.[4] Sixty percent of Canadians surveyed in 2006 who took a winter vacation in a sunny climate were age 44 and older.[5]
UVR levels are also higher than in the past. Over northern midlatitudes, current levels of UVR are 2% to 3% higher than in the 1970s and early 1980s. For comparison, UVR increases 2 times when travelling from southern Ontario to the Caribbean in spring.[6] Increases in UVR levels seen from the 1970s to 1990s were caused by decreases in ozone.[7] The ozone layer is recovering after a ban on ozone-depleting substances.[8]
Climate change and UVR exposure
Over the last few decades, the Earth has experienced warmer temperatures as a result of climate change and global warming.[9] Warmer climates increase the time people spend outdoors on more days of the year[10] and will likely therefore result in increased exposure to ultraviolet radiation (UVR) and its harmful effects. Increasing temperatures may be particularly significant in the spring and early autumn when UVR can reach harmful levels and the use of sun protection may be less common.[5]
Prevention
The risk of developing skin cancer increases with long-term exposure to ultraviolet radiation (UVR), so the older someone is, the more likely they are to have had this type of long-term exposure. A history of sunburns is associated with an increased risk of all skin cancers,[11] and those who have already had melanoma have a higher risk of developing another melanoma.[12] The number of people age 50 and older in Ontario’s population is projected to increase in the future,[13] so it is likely that the number of skin cancers in people age 50 and older will continue to grow.
Fortunately, skin cancer is one of the most preventable cancers.[14] To reduce the future burden of cases, people in Ontario can take action to reduce their risk of getting skin cancer by not using tanning beds and practicing sun safety:[15]
- Seek shade between the hours of 11 a.m. to 3 p.m.
- Slip on protective clothing.
- Slap on a wide-brimmed hat.
- Slop on sunscreen with a sun protection factor (SPF) of 30 or higher.
- Slide on sunglasses.
Supporting and implementing strong shade policies, which involve providing shade for a broad range of municipally and privately owned sites, as well as other policies that reduce climate change and exposure to UVR, such as those that reduce time outdoors during peak sun hours, can reduce sun exposure for children, youth and outdoor workers. Programs or campaigns can improve knowledge, attitudes and behaviours on sun safety, such as Australia’s Slip! Slop! Slap! SunSmart campaign. Read more about these types of policies and programs and the opportunities to reduce UVR in the Prevention System Quality Index 2020 report.