Epidemiological evidence of carcinogenicity of sunbed use and of efficacy of preventive measures

Incidence and trends of first basal cell carcinomas in France between 1980 and 2019: a regional population-based registry study

BACKGROUND

Basal cell carcinoma (BCC) is the most frequent malignancy reported in populations with fair skin. In most countries, BCCs are only partially or not at all recorded, and incidence data are lacking.

OBJECTIVES

This study assessed the current incidence rates and trends in the only two French départements where BCCs have been recorded for several decades.

METHODS

This regional population-based study thus used data from two French cancer registries (Doubs and Haut-Rhin) where first-time BCC diagnoses were recorded. The European age-standardized incidence rates (EASR) were calculated per 100 000 person-years (PY). The trends and the annual percentages of change were assessed using joinpoint analysis.

RESULTS

In all, 48 989 patients were diagnosed with a first BCC in the study period. The median age at diagnosis was 69 years and the BCCs were mainly located on the head and neck (68.8%). In the Doubs area between 1980 and 2016, the EASR of BCC increased from 59.9 to 183.1 per 100 000 PY. The annual increase for men was 5.73% before 1999 and 1.49% thereafter, and among women 4.56% before 2001 and 1.31% thereafter. In the Haut-Rhin area, the EASR increased from 139.2 in 1991 to 182.8 per 100 000 PY in 2019. Among men, the EASR increased annually by 2.31% before 2000, and by 0.29% after 2000; among women, it increased by 0.95% over the entire period (1991-2019). In the most recent period and for these two départements, the age-specific incidence rates of BCC for men and women were close before the age of 60 years, except for the 40-49-year age group, where the rates were significantly higher among women. For patients aged 60 years and over, men had much higher rates of BCC.

CONCLUSIONS

BCC incidence has increased since 1980 and is still rising, particularly among men and the elderly. A slowing was observed from 2000, which could be explained by a shift in the management of BCCs and by the possible efficacy of prevention actions. This study provides insight into the BCC burden in France and highlights the need to maintain effective prevention strategies, as incidence is still increasing.

Current insights and future perspectives of ultraviolet radiation (UV) exposure: Friends and foes to the skin and beyond the skin

Ultraviolet (UV) radiation is ubiquitous in the environment, which has been classified as an established human carcinogen. As the largest and outermost organ of the body, direct exposure of skin to sunlight or UV radiation can result in sunburn, inflammation, photo-immunosuppression, photoaging and even skin cancers. To date, there are tactics to protect the skin by preventing UV radiation and reducing the amount of UV radiation to the skin. Nevertheless, deciphering the essential regulatory mechanisms may pave the way for therapeutic interventions against UV-induced skin disorders. Additionally, UV light is considered beneficial for specific skin-related conditions in medical UV therapy. Recent evidence indicates that the biological effects of UV exposure extend beyond the skin and include the treatment of inflammatory diseases, solid tumors and certain abnormal behaviors. This review mainly focuses on the effects of UV on the skin. Moreover, novel findings of the biological effects of UV in other organs and systems are also summarized. Nevertheless, the mechanisms through which UV affects the human organism remain to be fully elucidated to achieve a more comprehensive understanding of its biological effects.

Sun exposure practices, attitudes and knowledge among students and teachers at a University School of Health Sciences in Ecuador

Skin cancer incidence is increasing worldwide. Late adolescence and young adulthood are fundamental stages of life to acquire good sun exposure practices, regarding both personal involvement in skin cancer prevention and being a role model for others, especially in a health education environment. This descriptive cross-sectional study is based on the validated CHACES questionnaire to study sun exposure and photoprotection behavior among students and teachers at the School of Health Sciences in the National University of Chimborazo, Riobamba (Ecuador). University members (814 students (89.8 %) and 93 teachers (10.2 %)) were studied, with a predominance of females and light-skin phototypes in both groups. Similar results were obtained regarding sun exposure, with higher recreative exposure in the teachers' group and higher occupational exposure in students. However, students significantly showed lower avoiding midday sun (41.9 % vs 60.9 %), and lower use of sunglasses (10.1 % vs. 41.6 %). Attitudes towards the sun and photoprotection knowledge issues were also equivalent between students and teachers (6.1/10 vs 6.2/10). Students' sunburn rate last year reaches 88.4 % and 52.7 % in teachers (p < 0.001). Using a multivariable logistic regression model, we identified risk factors associated with a greater risk of sunburn in our population. This study highlights areas to be improved regarding knowledge, attitudes and, especially, practices of photoprotection, among students and teachers at the University of Chimborazo. These results point out that awareness-raising campaigns should be implemented to reduce sunburns, morbidity and mortality of skin cancer in this environment.

An Epidemiological Update on Indoor Tanning and the Risk of Skin Cancers

Indoor tanning (sunbeds, solarium) uses artificial ultraviolet radiation (UVR) to stimulate cosmetic tanning of the skin. Indoor tanning has been officially classified as a human carcinogen in 2009 by the International Agency for Research on Cancer of the World Health Organization (WHO). The differences in the prevalence of sunbed use across countries and over the years highlight underlying legislative, climatic, and cultural differences. Indoor tanning-seeking behaviors may be driven by motivations for an appealing appearance, largely influenced by gender and age, and several misconceptions that a prevacation tan safeguards the skin, that sunbeds can be used to treat acne or to increase vitamin D, or that tanning is a healthy habit. This review provides an epidemiological update on the prevalence of sunbed use, who tends to use sunbeds and why, and details the current evidence on the association of sunbeds with skin cancers, including cutaneous melanoma, basal cell carcinoma (BCC), and cutaneous squamous cell carcinoma (cSCC). A statistically significant higher risk of cutaneous melanoma, BCC and cSCC with the use of sunbeds has been consistently demonstrated. This risk of skin cancer is even higher with the more frequent use of sunbeds, underscoring a dose-response relationship, and in those first exposed to sunbeds at a younger age. Preventive measures against sunbed use include legislation restricting sunbed use, educational campaigns to inform and discourage from indoor tanning, as well as using the internet, online advertising messages and the social media to reach larger audiences and to promote an untanned appearance.

Effects of Engagement with a Social Media Campaign for Mothers to Prevent Indoor Tanning by Teens in a Randomized Trial

In a social media campaign aimed at reducing mothers' permissiveness for indoor tanning (IT) by their teenage daughters, a secondary analysis of campaign engagement effects on IT outcomes was performed. Mothers (n = 869) with daughters aged 14-17 were recruited in 34 states that did not ban IT by minors under age 18 for a randomized trial with follow-up at 12 months (end of intervention) and 18 months (6 months after intervention) post-randomization. Daughters' (n = 469) baseline and follow-up responses were analyzed too. Mothers received a Facebook feed on adolescent health topics that included posts about preventing IT (intervention) or prescription drug misuse (control). Engagement was measured by extracting reactions (e.g., like, sad, etc.) and comments posted by mothers to the campaign posts. Overall, 76.4% of posts received a reaction and/or comment. Mothers who engaged with IT posts were less permissive of daughters' IT immediately at the conclusion of the campaign (permit IT: -0.39, p < .05; facilitate IT: -0.29, p < .05) and 6 months after intervention (permit IT: -0.32, p < .05; facilitate IT: -0.31, p < .05) than mothers who did not engage with posts. Engagement with posts was essential to the success of a social media campaign for preventing IT by minors by reducing mothers' permissiveness.

The Skin We Live in: Pigmentation Traits and Tanning Behaviour in British Young Adults, an Observational and Genetically-Informed Study

Skin cancer incidence has been increasing worldwide, representing a particularly high burden for populations of European ancestry. Outdoor and indoor tanning using ultraviolet (UV) radiation devices are major risk factors for skin cancer. While tanning behaviours can be modified by targeted interventions to reduce skin cancer rates, there is insufficient evidence on the motivations for tanning preferences and their relationship with pigmentation phenotypes. The present observational and genetically-informed study investigates motives for tanning and the role that pigmentation phenotypes play on outdoor and indoor tanning behaviour in British young adults. This study included 3722 participants from the Avon Longitudinal Study of Parents and Children in South West England, with data on pigmentation features, tanning ability and preferences, and SNP genotypes. Liking to tan and outdoor tanning were strongly influenced by pigmentary traits and tanning ability. However, the association of these phenotypes with UV indoor tanning was weaker. Our results provide evidence to support the implementation of skin cancer preventative interventions that consider individual biological characteristics and motives for undergoing outdoor and indoor tanning.

Cutaneous melanoma attributable to UVR exposure in Denmark and Germany

BACKGROUND

Increasing incidence rates of cutaneous melanoma (CM) observed during the last five decades in white populations are largely attributed to increased exposure to solar ultraviolet radiation (UVR), often expressed as population attributable fraction (PAF). Thus, many CMs could be prevented by reducing UVR exposure. The aim of this study was to estimate the PAF of CM attributable to UVR exposure and demographic changes in Denmark and Saarland/Germany for the period 1943 to 2036.

MATERIAL AND METHODS

CM incidence data (ICD-10, C43) for Denmark (1943-2016) and the German Federal State of Saarland (1972-2016) were retrieved from the NORDCAN database and from the Saarland Cancer Registry. The number of CMs attributable to UVR exposure was calculated by comparing contemporary or predicted CM incidence rates with CM rates in Denmark during the years 1943-1946.

RESULTS

In Denmark, the proportion of CM cases attributable to UVR exposure increased from around 20% in 1947-1951 to 96% in 2012-2016; in the Federal State of Saarland, it increased from 50% in 1972-1976 to 90% in 2012-2016. Until 2032-2036, the PAF is expected to rise in Denmark to 97% and in the Saarland to 92%. The demographic influence, on the other hand, is rather small.

CONCLUSIONS

More than 90% of all CM in Germany and Denmark are attributable to UVR exposure, and in principle, preventable. These findings underline the need for primary prevention strategies, aiming to increase the awareness of melanoma and its risk factors and to promote behavioural changes that decrease sun exposure.

Results of a social media campaign to prevent indoor tanning by teens: A randomized controlled trial

Indoor tanning (IT) increases risk of developing skin cancer. A social media campaign to reduce mother’s permissiveness toward their teenage daughters IT was evaluated. Mothers (N = 869) of daughters aged 14–17 in 34 states without bans on IT by minors were enrolled in a randomized trial with assessments at baseline and 12-months follow-up in 2017–19. A year-long adolescent health campaign was delivered to all mothers. The intervention group received posts on preventing IT and the control group, posts about preventing prescription drug misuse. Daughters (n = 469; 54.0%) completed the assessments at baseline and 12 months. At 12-month follow-up, intervention-group mothers were less permissive of IT by daughters (unadjusted means = 1.70 [95% CI: 1.59, 1.80] v. 1.85 [1.73, 1.97] [5-point Likert scale], b = -0.152), reported more communication about avoiding IT with daughters (4.09 [3.84, 4.35] v. 3.42 [3.16, 3.68] [sum of 7 yes/no items], b = 0.213), and had lower intentions to indoor tan (1.41 [1.28, 1.55] v. 1.60 [1.43, 1.76] [7-point likelihood scale], b = -0.221) than control-group mothers. Daughters confirmed intervention-group mothers communicated about IT (3.81 [3.49, 4.14] v. 3.20 [2.87, 3.53] [sum of 7 yes/no items], b = 0.237) and shared IT posts (unadjusted percentages = 52.4% v. 36.4%, b = 0.438) more than control-group mothers. No differences were found in IT behavior, self-efficacy to refuse permission, and negative attitudes toward IT. A social media campaign may be an effective strategy to convince mothers to withhold permission for IT, which may help increase the effectiveness of state laws designed to reduce IT by minors by requiring parental permission.

Association Between State Indoor Tanning Legislation and Google Search Trends Data in the United States From 2006 to 2019: Time-Series Analysis

BACKGROUND

Exposure to ultraviolet radiation from the sun or indoor tanning is the cause of most skin cancers. Although indoor tanning has decreased in recent years, it remains most common among adolescents and young adults, whose skin is particularly vulnerable to long-term damage. US states have adopted several types of legislation to attempt to minimize indoor tanning among minors: a ban on indoor tanning among all minors, a partial minor ban by age (eg, <14 years), or the requirement of parental consent or accompaniment for tanning. Currently, only 6 US states have no indoor tanning legislation for minors.

OBJECTIVE

This study investigated whether internet searches (as an indicator of interest) related to indoor tanning varied across US states by the type of indoor tanning legislation, using data from Google Trends from 2006 to 2019.

METHODS

We conducted a time-series analysis of Google Trends data on indoor tanning from 2006 to 2019 by US state. Time-series linear regression models were generated to assess the Google Trends data over time by the type of indoor tanning legislation.

RESULTS

We found that indoor tanning search rates decreased significantly for all 50 states and the District of Columbia over time (P<.01). The searches peaked in 2012 when indoor tanning received marked attention (eg, indoor tanning was banned for all minors by the first state-California). The reduction in search rates was more marked for states with a complete ban among minors compared to those with less restrictive types of legislation.

CONCLUSIONS

Our findings are consistent with those of other studies on the association between indoor tanning regulations and attitudinal and behavioral trends related to indoor tanning. The main limitation of the study is that raw search data were not available for more precise analysis. With changes in interest and norms, indoor tanning and skin cancer risk among young people may change. Future studies should continue to determine the impact of such public health policies in order to inform policy efforts and minimize risks to public health.

Influence of the Exposome on Skin Cancer

Skin cancer is the most frequent type of cancer in humans. While exposure to solar radiation is the most widely known and relevant causal factor, the different degrees of individual risk have not been fully elucidated. Epidemiological studies show how the risk of skin cancer is affected by other types of radiation (eg, ionizing radiation), pesticides, particulate matter in air pollution, toxins (eg, arsenic) in water and some foods. Some living entities, such as polyomavirus and human papillomavirus, can also cause specific types of cancer. Lastly, lifestyle factors such as stress, sleep, and exercise may play a role, although only a few studies shed light on these factors. The abovementioned factors make up the exposome of skin cancer, that is, the set of environmental exposures that, together with the genome and microbiome, determine the onset of disease.

Ultraviolet Radiation Exposure: Some Observations and Considerations, Focusing on Some Italian Experiences, on Cancer Risk, and Primary Prevention

Solar ultraviolet radiation may cause acute and chronic health effects on the skin, eyes, and also on the immune system. Actinic keratosis, non-melanoma skin cancers, and malignant melanoma are the main long-term adverse skin effects. In the white population, the most common type of cancer worldwide is skin cancer, and the incidence of this cancer has increased during the last decades. The most important risk factor responsible for this trend seems to be Ultraviolet Radiation (UVR). IARC has classified UVR as being carcinogenic to humans. UV radiation exposure is ubiquitous; to study skin cancer risk, it is important to take into account the fact that UV exposure may occur both for occupational activities but also during vacation or recreational activities. Furthermore, exposure to artificial UVR such as those emitted by artificial devices, classified by IARC as carcinogenic to humans, is also to be considered. Due to the prominent role of UVR, primary prevention of skin cancer is very suitable, because when following specific rules this risk factor can be reduced. The incidence rate of skin cancer is higher in people with fair skin. Outdoor workers exposed to solar UVR are at risk of developing skin cancer, particularly non-melanoma skin cancers, and welders exposed to artificial UVR are at risk of developing ocular melanoma. A specific project on solar UVR risk in outdoor workers in Tuscany, Italy, has shown that outdoor workers had an unsatisfactory sun protection behaviour. The project demonstrates the complexity of studying UVR exposure and recommended the need for prevention programs. Risk increases with increasing ambient solar radiation and with unsafe behaviours in the sun or when using artificial UVR (e.g., sunbeds). Effective prevention strategies have to be adopted both for the outdoor workers and for the general population exposed to UVR. A standardized program of proven efficacy, such as that implemented in Australia, should also be implemented in other countries. All these strategies could contribute to the aim of decreasing the morbidity and mortality of cancers associated with this exposure. The aim of this paper is to provide an overview of UVR exposure risk, particularly occupational risk, and to give some elements to understand the complexity of the relation between UVR exposure and cancer risk, as well as to outline primary prevention measures, focusing also on Italian experiences that could be useful for providing additional elements of knowledge on this topic.