Analysis of Geographic and Environmental Factors and Their Association with Cutaneous Melanoma Incidence in Canada

Abstract

<b><i>Background:</i></b> Over 90% of skin cancers including cutaneous melanoma (CM) are related directly to sun exposure. Despite extensive knowledge on ultraviolet radiation’s (UVR) detrimental impact, many still fail to implement sun protection/sun avoidance. Human behavior, attitudes, and cultural norms of individuals and communities heavily depend on the surrounding climate/environment. In many instances, the climate shapes the culture/norms of the society. Canada has vast geographic/environmental differences. <b><i>Methods:</i></b> In the current ecological study, we sought to examine the relationship between various geographic and environmental factors and the distribution of CM incidence by Forward Sortation Area (FSA) postal code across Canada. CM incidence data were extracted from the Canadian Cancer Registry, while environmental data were extracted from the Canadian Urban Environmental Health Research Consortium (greenspace, as measured by the normalized difference vegetation index; annual highest temperature; absolute number and average length of yearly heat events; annual total precipitation [rain and snow]; absolute number and average length of events with precipitation [rain and snow]; and summer UVR index). The above geographic/environmental data by FSA were correlated with the respective CM incidence employing negative binomial regression model. <b><i>Results:</i></b> Our analysis highlights that increases in annual average temperature, summer UVR, and greenspace were associated with higher expected incidence of CM cases, while higher number of annual heat events together with highest annual temperature and higher average number of annual rain events were associated with a decrease in CM incidence rate. This study also highlights regional variation in environmental CM risk factors in Canada. <b><i>Conclusions:</i></b> This national population-based study presents clinically relevant conclusions on weather/geographic variations associated with CM incidence in Canada and will help refine targeted CM prevention campaigns by understanding unique weather/geographic variations in high-risk regions.

Understanding the Perceived Relationship between Sun Exposure and Melanoma in Atlantic Canada: A Consensual Qualitative Study Highlighting a “Sunscreen Paradox”

“…Across all groups, there was a range of behaviors from diligent and proactive sun protection to a more reactive approach based on expected sun exposure. However, the NS and PEI groups showed more regular habits of sunscreen use, possibly due to a higher awareness or due to environmental factors [12]. For example, a participant from PEI said: "I always have sunscreen in my purse in case I get caught out.…”

“…Given the geographic proximity and the sense of regional identity that has been well documented [21][22][23], it is appropriate to consider the Atlantic Region as an important geographic and cultural unit in Canada. Thus, investigating sociocultural aspects as per people's perspectives regarding sun exposure may contribute to a better understanding of the collected evidence in recent quantitative studies [8,11,12]. This may ultimately help shape public health campaigns that support sustained behavioral change.…”

“…Within the Canadian population, several sociodemographic variables have been associated with sun exposure rates and subsequent CM development, including geographic latitude, climate, vegetation, genetic predisposition, Fitzpatrick skin phototype, socioeconomic status, occupation, and behavioral habits [7,[10][11][12]. Indeed, extensive evidence reveals that CM is largely preventable with the use of sun protection measures [13][14][15], such as the use of sunscreen and sun-protective clothing as well as avoidance of intense sun, sun tanning and sunburns.…”

MicroRNA-155 and Disease-Related Immunohistochemical Parameters in Cutaneous Melanoma

“…An epidemiological evaluation of the global burden estimated that 325,000 new cases of melanoma associated with 57,000 deaths occurred in 2020, with an estimated increase to 510,000 new cases and 96,000 deaths by 2040 [ 1 ]. Significant geographical variations in incidence rates across countries and world regions have been observed [ 2 ]. Risk factors associated with the development of cutaneous melanoma include fair skin and hair, excessive sun exposure, a family history of melanoma, and the presence of numerous or atypical moles, among others [ 3 ].…”

The Contributions of Cancer-Testis and Developmental Genes to the Pathogenesis of Keratinocyte Carcinomas

“…KCs are malignancies that arise from epidermal keratinocytes. Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) are the two types of KC, representing the first and fifth most prevalent cancers, respectively, worldwide [ 24 , 25 , 26 , 27 , 28 ]. BCC arises from keratinocytes in the basal layer of the interfollicular epidermis, mechanosensory niches and from hair follicle infundibulum stem cells [ 29 ].…”