Sun and Solarium Exposure and Melanoma Risk: Effects of Age, Pigmentary Characteristics, and Nevi

The effect of solarium light therapy on selected biological and biochemical parameters of peripheral blood in young and old horses

The aim of the study was to assess the impact of solarium light therapy on selected biological and biochemical parameters of peripheral blood in recreational horses. The study involved 10 horses divided into two groups of young (aged 5 to 7 years) and old (aged 14 to 19 years) individuals. All animals participated in light therapy sessions every other day. Blood was sampled three times during the study: before the treatment, after five light sessions, and after ten light sessions. Morphological parameters, the activity of antioxidant enzymes, TAS values, and the levels of glutathione (GSH), vitamin D3, vitamin C, and malondialdehyde (MDA) were measured in the whole blood. Light therapy contributed to an increase in MCV, HDW, MCVr, CHr and MPV indices, and simultaneously a decrease in the basophil counts, MCHC, RDW and CHCMr indices in both groups of horses (p ≤ 0.05). At the same time reticulocytes fell in older whereas white blood cells and monocytes counts expanded in younger individuals. The treatment also increased the activity of glutathione reductase (GR) and glutathione peroxidase (GPx) in young but decreased the activity of mentioned enzymes in blood plasma of old horses. The total antioxidant status (TAS) of the blood plasma rose progressively, whereas GSH levels declined in all individuals. Moreover, vitamin D3 levels did not change, whereas vitamin C levels gradually decreased during the experiment. The therapy also helped to reduce levels of MDA in the blood plasma, especially of older horses (p ≤ 0.05). In turn, GPx and GR activities as well as MDA levels significantly declined, whereas GSH levels notably elevated in erythrocytes (p ≤ 0.05). Solarium light therapy appears to have a beneficial impact on the morphological parameters and antioxidant status of blood in recreational horses in the winter season. However, the observed results could in part be attributed to the natural physiological adaptation of each individual organism to the treatment.

Natural hair color and skin cancers: A two-sample Mendelian randomization study

Previous observational studies have indicated an association between hair color and the risk of melanoma and keratinocyte skin cancer (KSC); however, different hair colors show inconsistent effects on skin cancers. Here, we conducted a two-sample Mendelian randomization (MR) study to evaluate the causal relationship between natural hair color and skin cancers by using 211 single nucleotide polymorphisms as genetic instruments from a genome-wide meta-analysis of 360,270 individuals of European ancestry. Light hair colors (red, blonde, and light brown) were associated with high levels of cutaneous melanoma (CM) and KSC (CM-inverse variance weighted [IVW] odds ratio [OR]-red: 1.034, 95% confidence interval [CI]: 1.025-1.044, P < 0.001; OR-blonde: 1.008, 95% CI: 1.003-1.014, P = 0.003; OR-light brown: 1.006, 95% CI: 1.002-1.011, P = 0.009; KSC-IVW OR-red: 1.078, 95% CI: 1.053-1.103, P < 0.001; OR-blonde: 1.024, 95% CI: 1.009-1.040, P = 0.002; OR-light brown: 1.018, 95% CI: 1.004-1.033, P = 0.01). However, dark brown hair showed an inverse causal relationship with skin cancers (CM IVW OR: 0.987, 95% CI: 0.984-0.990, P < 0.001; KSC IVW OR: 0.979, 95% CI: 0.970-0.988, P < 0.001). Black hair was associated with a decreased risk of KSC (IVW OR: 0.954, 95% CI: 0.913-0.997, P = 0.036) but showed no causal relationship with CM. The present study provides strong MR evidence of a causal association between hair color and skin cancer. Secondary MR analyses enhances result robustness by replicating findings, exploring gender-specific effects, and providing a more comprehensive understanding of the complex relationship between hair color and skin cancers. More large-scale MR studies or randomized controlled trials are required to further investigate the mechanisms of the association between hair color and skin cancers.

Vitamin D and potential effects on cancers: a review

Cancer is characterized by the abnormal and uncontrollable division and growth of cells that can infiltrate tissues and alter normal physiological function, which will become crucial and life-threatening if left untreated. Cancer can be a result of genetics, such as mutations or environmental causes, including smoking, lack of physical activity, as well as nutritional imbalance in the body. Vitamin D is one of the foremost nutrients that play a crucial role in a variety of biochemical pathways, and it is an important key factor in several diseases. Vitamin D is an essential nutrient for preventing malignancies and a complementary treatment for cancer through direct and indirect biochemical pathways. In this article, we summarized the correlation between vitamin D and various cancers using an extensive search on PubMed, Google Scholar, and Scopus. This paper reviews the role of vitamin D in different types of cancer.

Skin Cancer-Related Health Behavior Interventions in the Context of the Health Belief Model

The incidence of skin cancer is increasing around the world every year. Although there are many reasons for the occurrence of skin cancer, UV radiation caused by sunlight is seen as the most important factor. Therefore, reducing exposure to UV radiation should be a top priority for skin cancer prevention. In addition, different demographic features also affect the amount of UV exposure. These include age, gender and professional groups. On the other hand, people can be exposed to UV radiation voluntarily. Sunbathing or using tanning devices can be shown as examples for this. For these reasons, interventions to reduce exposure to UV radiation should focus on demographic features and the desire to tan. At the same time, it is emphasized in the literature that theory-based and systematic interventions are more effective than others. In this context, we think that the Health Belief Model, which is an effective psychosocial model for health behaviors, will be useful in developing sun protection behaviors. In this review, interventions based on the Health Belief Model in the context of tanning behavior, age, gender, and outdoor activities for the prevention of skin cancer and the improvement of sun protection behaviors have been discussed.

Mortality of Malignant Melanoma in Central Serbia, in the Period 1999-2015

INTRODUCTION

Malignant melanoma is one of the rarest forms of skin cancer but it is the most deadly.

OBJECTIVE

The objective of this paper was to analyze the epidemiological characteristics and trends of mortality from malignant melanoma in the population of Central Serbia in the period 1999-2015.

METHODS

The study was designed as a retrospective descriptive epidemiological study. Standardized mortality rates were used in statistical data processing. A linear trend model and regression analysis were used to examine trends in malignant melanoma mortality.

RESULTS

In Serbia, malignant melanoma mortality shows an increasing trend. The overall age-adjusted melanoma death rate was 2.6 per 100,000 with a higher death rate among men (3.03 per 100,000) than among women (2.1 per 100,000). Malignant melanoma mortality rates increase with age in both sexes and are highest in the age group of 75 and older. The highest increase in mortality in men is recorded in the 65-69 age group, with an average percentage increase of 21.33 (95% CI, 8.40 - 51.05), while in women the largest increase in mortality was recorded in the 35-39 age group, with an average percentage increase of 31.4 and in the 70-74 age group, 12.9.

CONCLUSIONS

The trend of increasing mortality from malignant melanoma in Serbia is similar to those in most developed countries. Education and improvement of awareness in the general population and among health professionals are vital to reducing melanoma mortality in the future.

Lifetime Sunburn Trajectories and Associated Risks of Cutaneous Melanoma and Squamous Cell Carcinoma Among a Cohort of Norwegian Women

Importance

To our knowledge, no study has prospectively investigated sunburn patterns over age periods from childhood to adulthood and their associations with skin cancer risk.

Objective

To identify lifetime trajectories of sunburns and compare the association between these trajectories and subsequent risk of cutaneous melanoma and squamous cell carcinoma (cSCC).

Design, Setting, and Participants

This population-based cohort study included participants from the Norwegian Women and Cancer Study, established in 1991, with follow-up through 2018. Baseline questionnaires were issued from 1991 to 2007, with follow-up questionnaires every 5 to 7 years. Data analysis was performed from March 16, 2021, to December 4, 2021.

Exposures

Participants reported pigmentation factors, sunbathing vacations, and indoor tanning. Annual frequencies of sunburns were reported for childhood, adolescence, and adulthood.

Main Outcomes and Measures

Information on cancer diagnoses, emigration, and death were obtained through linkage to the Cancer Registry of Norway using the unique personal identification number of Norwegian citizens.

Results

Of the 172 472 women (age range, 31-70 years) who returned questionnaires, 169 768 received questions about sunburns at study inclusion. Five classes (stable low, low-moderate-low, low to high, high to low, and stable high) of individual lifetime sunburn trajectories with similar shapes were estimated in 3 samples up to 39 years (n = 159 773), up to 49 years (n = 153 297), and up to 59 years (n = 119 170). Mean follow-up ranged from 14.3 to 19.5 years in the 3 samples, during which 1252 to 1774 women were diagnosed with incident primary melanoma and 739 to 871 women with incident primary cSCC. With hazard ratios (HRs) and 95% CIs estimated using a Cox proportional hazards model, the stable high and high to low trajectories showed statistically significant increased melanoma and cSCC risks compared with the stable low trajectory across all samples (≤39 years for stable high and high to low trajectories: melanoma: HR, 1.50 [95% CI, 1.28-1.75] and HR, 1.44 [95% CI, 1.20-1.73]; cSCC: HR, 1.51 [95% CI, 1.22-1.87] and HR, 1.47 [95% CI, 1.14-1.91]). Other trajectories showed increased risk, though generally weaker and mainly estimates that were not statistically significant. There was no statistically significant heterogeneity between melanoma and cSCC estimates.

Conclusion and Relevance

This cohort study showed that high sunburn frequency throughout life was associated with increased melanoma and cSCC risk. Furthermore, sunburns in childhood are especially important for subsequent risk of these skin cancers. Avoiding sunburns throughout life, in particular in childhood, is therefore crucial.

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.

Higher polygenic risk for melanoma is associated with improved survival in a high ultraviolet radiation setting

BACKGROUND

The role of germline genetic factors in determining survival from cutaneous melanoma (CM) is not well understood.

OBJECTIVE

To perform a genome-wide association study (GWAS) meta-analysis of melanoma-specific survival (MSS), and test whether a CM-susceptibility polygenic risk score (PRS) is associated with MSS.

METHODS

We conducted two Cox proportional-hazard GWAS of MSS using data from the Melanoma Institute Australia, a high ultraviolet (UV) radiation setting (MIA; 5,762 patients with melanoma; 800 melanoma deaths) and UK Biobank (UKB: 5,220 patients with melanoma; 241 melanoma deaths), and combined them in a fixed-effects meta-analysis. Significant (P < 5 × 10-8) results were investigated in the Leeds Melanoma Cohort (LMC; 1,947 patients with melanoma; 370 melanoma deaths). We also developed a CM-susceptibility PRS using a large independent GWAS meta-analysis (23,913 cases, 342,870 controls). The PRS was tested for an association with MSS in the MIA and UKB cohorts.

RESULTS

Two loci were significantly associated with MSS in the meta-analysis of MIA and UKB with lead SNPs rs41309643 (G allele frequency 1.6%, HR = 2.09, 95%CI = 1.61-2.71, P = 2.08 × 10-8) on chromosome 1, and rs75682113 (C allele frequency 1.8%, HR = 2.38, 95%CI = 1.77-3.21, P = 1.07 × 10-8) on chromosome 7. While neither SNP replicated in the LMC, rs75682113 was significantly associated in the combined discovery and replication sets. After adjusting for age at diagnosis, sex and the first ten principal components, a one standard deviation increase in the CM-susceptibility PRS was associated with improved MSS in the discovery meta-analysis (HR = 0.88, 95% CI = 0.83-0.94, P = 6.93 × 10-5; I2 = 88%). However, this was only driven by the high UV setting cohort (MIA HR = 0.84, 95% CI = 0.78-0.90).

CONCLUSION

We found two loci potentially associated with MSS. Increased genetic susceptibility to develop CM is associated with improved MSS in a high UV setting.

Pre-diagnostic DNA methylation in blood leucocytes in cutaneous melanoma; a nested case-control study within the Norwegian Women and Cancer cohort

The prognosis of cutaneous melanoma depends on early detection, and good biomarkers for melanoma risk may provide a valuable tool to detect melanoma development at a pre-clinical stage. By studying the epigenetic profile in pre-diagnostic blood samples of melanoma cases and cancer free controls, we aimed to identify DNA methylation sites conferring melanoma risk. DNA methylation was measured at 775,528 CpG sites using the Illumina EPIC array in whole blood in incident melanoma cases (n = 183) and matched cancer-free controls (n = 183) in the Norwegian Women and Cancer cohort. Phenotypic information and ultraviolet radiation exposure were obtained from questionnaires. Epigenome wide association (EWAS) was analyzed in future melanoma cases and controls with conditional logistic regression, with correction for multiple testing using the false discovery rate (FDR). We extended the analysis by including a public data set on melanoma (GSE120878), and combining these different data sets using a version of covariate modulated FDR (AdaPT). The analysis on future melanoma cases and controls did not identify any genome wide significant CpG sites (0.85 ≤ padj ≤ 0.99). In the restricted AdaPT analysis, 7 CpG sites were suggestive at the FDR level of 0.15. These CpG sites may potentially be used as pre-diagnostic biomarkers of melanoma risk.

Perspectives for Combining Viral Oncolysis With Additional Immunotherapies for the Treatment of Melanoma

Melanoma is the deadliest type of skin cancer with steadily increasing incidence worldwide during the last few decades. In addition to its tumor associated antigens (TAAs), melanoma has a high mutation rate compared to other tumors, which promotes the appearance of tumor specific antigens (TSAs) as well as increased lymphocytic infiltration, inviting the use of therapeutic tools that evoke new or restore pre-existing immune responses. Innovative therapeutic proposals, such as immune checkpoint inhibitors (ICIs), have emerged as effective options for melanoma. However, a significant portion of these patients relapse and become refractory to treatment. Likewise, strategies using viral vectors, replicative or not, have garnered confidence and approval by different regulatory agencies around the world. It is possible that further success of immune therapies against melanoma will come from synergistic combinations of different approaches. In this review we outline molecular features inherent to melanoma and how this supports the use of viral oncolysis and immunotherapies when used as monotherapies or in combination.

Population-Based Study Detailing Cutaneous Melanoma Incidence and Mortality Trends in Canada

Background

Cutaneous melanoma (CM) is one of the most fatal types of skin cancer. Alarmingly, increases in incidence and mortality were noted globally for this malignancy, despite increase in understanding of melanoma pathogenesis and enhanced prevention efforts.

Methods

Data was extracted for CM patients for provinces and territories (except Quebec) using two independent, population-based registries. Analysis was performed using both clinical and pathological characteristics: tumor morphologic classification, age, sex, anatomic site affected and place of residence. Mortality trends were assessed over a 7-year period. Results were compared to prior findings for 1992-2010.

Results

During 2011-2017 39,610 patients were diagnosed with CM, with 5,890 reported deaths. National crude CM incidence was 20.75 (age-standardized incidence: 14.12) cases per 100,000 individuals per year. Females accounted for 45.8% of cases and 37.1% of deaths. While CM incidence rates continue to increase in both sexes, since 2013 the CM mortality is declining. We observed important differences across the provinces/territories, where Nova Scotia, Prince Edward Island, southern Ontario/British Columbia and certain coastal communities of New Brunswick demonstrated higher CM incidence and mortality rates. The observed incidence and mortality trends for 2011-2017 validate and extend earlier observations from 1992 to 2010 for CM.

Conclusion

This population-based study highlights that while melanoma's incidence is increasing in Canada, mortality rates are for the first time decreasing since 2013. We detail regional distribution of this cancer highlighting communities in southern/coastal areas, as being most at risk as well as the latest trends of melanoma incidence by age, sex and anatomic site. In males, melanoma is more common on the head/trunk, while in females on the extremities. Notably, Acral Lentiginous Melanoma was the only CM subtype that was more common in females, which primarily affects hands and feet.

Effect of an interactive educational activity using handheld ultraviolet radiation dosimeters on sun protection knowledge among Australian primary school students

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This interactive educational activity incorporated handheld UV dosimeters.

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The intervention improved UV-related knowledge among primary school students.

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Knowledge about the UV Index improved the most.

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Knowledge about UV harms, sun protective clothing and behaviours also improved.

Ultraviolet radiation (UV) is the main cause of skin cancer, and children are a priority group for reducing UV exposure. We evaluated whether an interactive educational activity using handheld dosimeters improved UV-related knowledge among primary (elementary) school students. We conducted an uncontrolled before-after study among 427 students in grades 3–6 (ages 8–12 years) at five schools in the Greater Sydney region, Australia. Students used UV dosimeters to measure UV exposure, using the UV index scale, at different locations on their school grounds with and without different forms of sun protection, followed by an indoor classroom presentation and discussion. A 10-point anonymous questionnaire was completed by each student before and after the entire session (60–90 min). Before-after responses were compared using a generalised linear mixed model, adjusted for school, grade and gender. Overall, the mean raw scores increased from 6.3 (out of 10) before the intervention to 8.9 after the intervention, and the adjusted difference in scores was 2.6 points (95% confidence interval 2.4–2.8; p < 0.0001). Knowledge improved for all questions, with the greatest improvement for questions related to the UV Index (p < 0.05). The effect of the intervention was similar across different school, grade and gender groups. School and grade had no significant effect on mean survey scores, but girls scored an average 0.2 points higher than boys (95% confidence interval 0.1–0.4; p = 0.01). In conclusion, Australian primary school students had moderate knowledge about UV and sun protection, and knowledge improved significantly after a short interactive educational activity using handheld UV dosimeters.

Indoor Tanning and the Risk of Overall and Early-Onset Melanoma and Non-Melanoma Skin Cancer: Systematic Review and Meta-Analysis

Simple Summary

Motivated by the increasing incidences of skin cancer, in 2015, Australian states banned indoor tanning to prevent exposure to artificial ultraviolet light. However, there has been no study investigating the association between indoor tanning and early-onset melanoma and non-melanoma skin cancer. In this study, we reviewed a total of 54 studies to examine the association between indoor tanning device use and overall and early-onset skin cancer. We found that indoor tanning is associated with increased risk for early-onset melanoma and NMSC, and has a dose–response relationship with first exposure at an early age and the frequency of exposure. Therefore, this study emphasizes the importance of avoiding indoor tanning risk in younger adults. Our findings provide evidence that supports policies regulating the excessive use of tanning devices, especially in the vulnerable younger population, to reduce the additional risk of skin cancer.

Abstract

The aim of this study was to examine the association between indoor tanning use and the risk of overall and early-onset (age < 50) melanoma and non-melanoma skin cancer (NMSC). To evaluate the association between indoor tanning and skin cancer, a systematic review of the literature published until July 2021 was performed using PubMed, EMBASE, and MEDLINE. Summary relative risk (RR) from 18 studies with 10,406 NMSC cases and 36 studies with 14,583 melanoma cases showed significant association between skin cancer and indoor tanning (melanoma, RR= 1.27, 95% CI 1.16–1.39; NMSC, RR = 1.40, 95% CI 1.18–1.65; squamous cell carcinoma (SCC), RR = 1.58, 95% CI 1.38–1.81; basal cell carcinoma (BCC), RR = 1.24, 95% CI 1.00–1.55). The risk was more pronounced in early-onset skin cancer (melanoma, RR = 1.75, 95% CI 1.14–2.69; NMSC, RR = 1.99, 95% CI 1.48–2.68; SCC, RR = 1.81, 95% CI 1.38–2.37; BCC, RR = 1.75, 95% CI 1.15–2.77). Moreover, first exposure at an early age (age ≤ 20 years) and higher exposure (annual frequency ≥ 10 times) to indoor tanning showed increasing risk for melanoma (RR = 1.47, 95% CI 1.16–1.85; RR = 1.52, 1.22–1.89) and NMSC (RR = 2.02, 95% CI 1.44–2.83; RR = 1.56, 95% CI 1.31–1.86). These findings provide evidence supporting primary prevention policies regulating modifiable behaviors to reduce the additional risk of skin cancer among younger adults.

The association between citrus consumption and melanoma risk in the UK Biobank

BACKGROUND

Melanoma incidence has been dramatically increasing worldwide. Psoralen, a known photocarcinogen, is naturally abundant in citrus products, leading to the hypothesis that high citrus consumption may increase melanoma risk.

OBJECTIVES

To investigate the association between total citrus consumption and melanoma risk, and the association between individual citrus products and melanoma risk, and to test for interactions between total citrus intake and established melanoma risk factors.

METHODS

Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between citrus consumption and melanoma risk among 1592 cases and 197 372 controls from the UK Biobank cohort. Citrus consumption data were collected via five rounds of 24-h recall questionnaires. International Classification of Diseases codes were used to determine melanoma outcome.

RESULTS

After adjusting for potential confounders, participants in the highest category of total citrus intake (> 2 servings per day) had a significantly increased risk of melanoma (OR 1·63, 95% CI 1·24-2·12) relative to those with no consumption. For individual citrus products, participants with the most orange and orange juice consumption (> 1 serving per day) had a significantly increased melanoma risk relative to those with no consumption (OR 1·79, 95% CI 1·07-2·78 and OR 1·54, 95% CI 1·10-2·10, respectively). Fair- or very fair-skinned participants with high citrus consumption had an even greater melanoma risk (OR 1·75, 95% CI 1·31-2·29).

CONCLUSIONS

High citrus consumption was associated with an increased risk of melanoma in a large, prospective, population-based cohort. Further validation of these findings could lead to improved melanoma prevention strategies.

Ultraviolet radiation and risk of cutaneous melanoma and squamous cell carcinoma in males and females in the Norwegian Offshore Petroleum Workers cohort

BACKGROUND

Increased risk of cutaneous melanoma and squamous cell carcinoma (SCC) has been reported among petroleum workers, but few studies include females, exposure data on ultraviolet radiation (UVR), and potential confounding factors. We aimed to examine UVR exposure in relation to risk of melanoma and SCC among male and female offshore petroleum workers. We also examined the association between UVR exposure and melanoma (Breslow) thickness.

METHODS

The Norwegian Offshore Petroleum Workers (NOPW) cohort (n = 27,917) holds information on sunbathing, indoor tanning, sunburns, sunscreen use, and other lifestyle factors recorded in 1998. Linkage to the Cancer Registry of Norway gave information on cancer diagnosis through 2017. We used Cox and logistic regression to estimate hazard ratios (HRs) of skin cancer and odds ratios (OR) of thick (≥1 mm) melanomas, respectively, with 95% confidence intervals (CIs).

RESULTS

Melanoma risk increased with increasing frequency of sunbathing after age 20 (ptrend  = 0.031), sunburn average intensity (ptrend  = 0.028), and sunscreen use (HR = 2.16; 95% CI: 1.42 -3.27 for almost always vs. never/rarely). The risk of thick melanoma was inversely associated with sunbathing frequency after age 20 (OR = 0.38; 95% CI: 0.16 - 0.90 for ≥4 weeks/year vs. 1 week/year). SCC risk increased with increasing frequency of indoor tanning after age 20 (HR = 2.72; 95% CI: 1.22 - 6.05 for ≥3 times/months vs. never), sunburn average intensity (ptrend  < 0.001), and sunscreen use (ptrend  < 0.001).

CONCLUSIONS

Our results support associations between UVR exposure and skin cancer risk in male and female offshore petroleum workers. This occupational group may be especially relevant for targeted sun protection advice.

Use of Fertility Drugs and Risk of Malignant Melanoma: Results from a Large Danish Population-Based Cohort Study

Fertility drugs have not definitively been linked to malignant melanoma. By the use of data from a large nationwide cohort of women aged 20.0-45.0 years and living in Denmark between January 1, 1995 and December 31, 2011, we assessed the association between the use of fertility drugs and the risk of malignant melanoma. Information on fertility status and the use of fertility drugs was obtained from the population-based Danish Infertility Cohort. Cox proportional hazard regression models were applied to estimate hazard ratios and 95% confidence intervals with adjustment for potential confounders. The study population comprised 1,330,954 women, of whom 86,231 (6.5%) were treated with fertility drugs. During a median follow-up of 21.0 years, 6,139 women were diagnosed with malignant melanoma. Compared with fertile women, women with fertility challenges who had used any fertility drugs had an increased risk of malignant melanoma (hazard ratio = 1.14; 95% confidence interval = 1.02-1.27). Furthermore, the use of specific types of fertility drugs (clomiphene, gonadotropins, human chorionic gonadotropin, gonadotropin-releasing hormone preparations, and progesterone) was also associated with an increased risk of malignant melanoma, with hazard ratios ranging between 1.09 and 1.13; however, the association did not reach statistical significance. Our findings indicate that the use of fertility drugs was associated with a modestly increased risk of malignant melanoma.

On Naevi and Melanomas: Two Sides of the Same Coin?

Benign naevi are closely linked to melanoma, as risk factors, simulators, or sites of melanoma formation. There is a heavy genetic overlap between the two lesions, a shared environmental influence of ultraviolet radiation, and many similar cellular features, yet naevi remain locally situated while melanomas spread from their primary site and may progress systemically to distal organs. Untangling the overlapping contributors and predictors of naevi and melanoma is an ongoing area of research and should eventually lead to more personalized prevention and treatment strategies, through the development of melanoma risk stratification tools and early detection of evolving melanomas. This will be achieved through a range of complementary strategies: risk-adjusted primary prevention counseling; the use of lesion imaging technologies such as sequential 3D total body photography and consumer-performed lesion imaging; artificial intelligence deep phenotyping and clinical assistance; a better understanding of genetic drivers of malignancy, risk variants, clinical genetics, and polygenic effects; and the interplay between genetics, phenotype and the environment.

Solarium Use and Risk for Malignant Melanoma: Many Open Questions, Not the Time to Close the Debate

To shed further light on the ongoing debate whether sunbed use may increase melanoma risk, we have critically assessed the scientific literature that is at present available, focussing on a meta-analysis that we published recently. Our literature search identified several meta-analyses that report a weak association for ever-exposure to UV radiation from a solarium with melanoma risk. However, the quality of studies included in these meta-analyses and the resulting evidence levels and grades of recommendation were very low due to the lack of interventional trials and because of severe limitations of many of the observational studies. The results of cohort and case-control studies published until today do not prove causality, not even by the Hill criteria. The overall quality of these observational studies and the resulting evidence levels are low due to severe limitations (including unobserved or unrecorded confounding), which leads to bias. It must be recognized that in the majority of studies, published to date, many of the confounding factors, including sun exposure, sunburns and skin type, have not been adequately and systematically recorded and adjusted for. We conclude that the many limitations of the individual studies and the resulting low levels of evidence and grades of recommendation do at present not allow postulation of a causal relationship between solarium use and melanoma risk. At present, there is no convincing evidence that moderate/responsible solarium use increases melanoma risk.

Benefit-Cost Analysis of the Danish Sun Safety Campaign 2007-2015: Cost Savings from Sunburn and Sunbed Use Reduction and Derived Skin Cancer Reductions 2007-2040 in the Danish Population

BACKGROUND

Ninety percent of skin cancers are avoidable. In Denmark, 16,500 cases of melanoma and keratinocyte cancers were registered in 2015. The Danish Sun Safety Campaign has campaigned since 2007, targeting overexposure to ultraviolet radiation. During 2007-2015, the key indicators of skin cancer, i.e. sunbed use and sunburn, showed annual reductions of 6% and 1%, respectively.

OBJECTIVES

We aimed to examine the financial savings to society as a result of the campaign reductions in skin cancer cases (2007-2040), and to examine the campaign's cost-benefit and return on investment (ROI).

METHODS

The analysis is based on existing data: (1) annual population-based surveys regarding the Danish population's behavior in the sun; (2) skin cancer projections; (3) relative risks of skin cancers from sunburn and sunbed use and (4) historical cancer incidences, combined with new data; (5) benefits from the avoided costs of skin cancer reductions; and (6) the costs of the Danish Sun Safety Campaign.

RESULTS

The results were based on a reduction of 9000 skin cancer cases, saving €29 million of which €13 million were derived from sunburn reductions and €16 million from reductions in sunbed use. The ROI was €2.18.

CONCLUSION

Skin cancer prevention in Denmark is cost effective. Every Euro spent by the Danish Sun Safety Campaign saved the Danish health budget €2.18 in health expenses.

A Process Evaluation of the Skin Cancer Prevention Act (Tanning Beds): A Survey of Ontario Public Health Units

Evidence of the dangers of indoor tanning and its popularity, including among youth, led the Government of Ontario to pass the Skin Cancer Prevention Act (Tanning Beds) (SCPA) in 2014. This legislation includes prohibiting the sale of indoor tanning services to individuals under 18, requiring warning signs be posted, and other safety regulations. We collected information from Ontario Public Health Units to conduct a process evaluation of the SCPA to: understand legislation implementation; assess available evidence about compliance, inspection, and enforcement; and, note barriers and facilitators related to inspection and enforcement. Data was collected March-April 2018. All 36 Ontario Public Health Units were invited to participate in an online questionnaire about the SCPA. Questions covered complaints, inspection, and enforcement, and used both close- and open-ended questions. Participants from 20 Public Health Units responded to the questionnaire; a response rate of 56%. These agencies reported 485 facilities offer indoor tanning. Since 2014, there have been 242 infractions by tanning facility owner/operators related to the SCPA, with most being uncovered during non-mandatory routine inspections (n = 234, 97%), rather than mandatory complaint-based inspections (n = 8, 3%). Most infractions were related to warning signs (n = 201, 83%). No charges were issued for any infractions. Instead, providing education (n = 90, 62%) and issuing warnings (n = 33, 23%) were the most common enforcement strategies. SCPA amendments are needed, including mandatory, routinely scheduled inspections. In addition to providing education, fines may improve compliance. More resources are required for inspection and enforcement of the SCPA.

Multimodel preclinical platform predicts clinical response of melanoma to immunotherapy

Although immunotherapy has revolutionized cancer treatment, only a subset of patients demonstrate durable clinical benefit. Definitive predictive biomarkers and targets to overcome resistance remain unidentified, underscoring the urgency to develop reliable immunocompetent models for mechanistic assessment. Here we characterize a panel of syngeneic mouse models, representing a variety of molecular and phenotypic subtypes of human melanomas and exhibiting their diverse range of responses to immune checkpoint blockade (ICB). Comparative analysis of genomic, transcriptomic and tumor-infiltrating immune cell profiles demonstrated alignment with clinical observations and validated the correlation of T cell dysfunction and exclusion programs with resistance. Notably, genome-wide expression analysis uncovered a melanocytic plasticity signature predictive of patient outcome in response to ICB, suggesting that the multipotency and differentiation status of melanoma can determine ICB benefit. Our comparative preclinical platform recapitulates melanoma clinical behavior and can be employed to identify mechanisms and treatment strategies to improve patient care.

Predicting the Risk of Melanoma Metastasis Using an Immune Risk Score in the Melanoma Cohort

Melanoma is a highly aggressive cancer, attracting increasing attention worldwide. The 5-year survival rate of patients with metastatic melanoma is low. Therefore, it is critical to identify potential effective biomarkers for diagnosis of melanoma metastasis. In the present study, the melanoma cohort and immune genes were obtained from the Cancer Genome Atlas (TCGA) database and the ImmPort database, respectively. Then, we constructed the immune risk score (IRS) using univariate and multivariate logistic analysis. The area under the curve (AUC) of IRS in sequencing samples and the initial diagnosis patients was 0.90 and 0.80, respectively. Besides, IRS could add benefits for metastasis diagnosis. For sequencing samples, IRS (OR = 16.35, 95% CI = 8.74–30.59) increased the odds for melanoma metastasis. Similar results were obtained in the initial diagnosis patients (OR = 8.93, 95% CI = 3.53–22.61). A composite nomogram was built based on IRS and clinical information with well-fitted calibration curves. We further used other independent melanoma cohorts from Gene Expression Omnibus (GEO) databases to confirm the reliability and validity of the IRS (AUC > 0.75, OR > 1.04, and P value < 0.01 in all cohorts). In conclusion, IRS is significantly associated with melanoma metastasis and can be a novel effective signature for predicting the metastasis risk.

Lifetime Ultraviolet Radiation Exposure and DNA Methylation in Blood Leukocytes: The Norwegian Women and Cancer Study

Ultraviolet radiation (UVR) exposure is a leading cause of skin cancers and an ubiquitous environmental exposure. However, the molecular mechanisms relating UVR exposure to melanoma is not fully understood. We aimed to investigate if lifetime UVR exposure could be robustly associated to DNA methylation (DNAm). We assessed DNAm in whole blood in three data sets (n = 183, 191, and 125) from the Norwegian Woman and Cancer cohort, using Illumina platforms. We studied genome-wide DNAm, targeted analyses of CpG sites indicated in the literature, global methylation, and accelerated aging. Lifetime history of UVR exposure (residential ambient UVR, sunburns, sunbathing vacations and indoor tanning) was collected by questionnaires. We used one data set for discovery and the other two for replication. One CpG site showed a genome-wide significant association to cumulative UVR exposure (cg01884057) (pnominal = 3.96e-08), but was not replicated in any of the two replication sets (pnominal ≥ 0.42). Two CpG sites (cg05860019, cg00033666) showed suggestive associations with the other UVR exposures. We performed extensive analyses of the association between long-term UVR exposure and DNAm. There was no indication of a robust effect of past UVR exposure on DNAm.

Association of Indoor Tanning Exposure With Age at Melanoma Diagnosis and BRAF V600E Mutations

There is limited information on how indoor tanning promotes melanoma development. We investigated indoor tanning use in patients with melanomas in sun-exposed skin and studied the clinicopathological and molecular characteristics in relation to indoor tanning exposure. Patients from a multidisciplinary clinic for cutaneous cancers completed standardized questionnaires on risk factors for melanoma as a component of medical history at their initial consultations. For this study, we included patients from December 2013 to May 2015. The 114 patients who reported indoor tanning exposure were younger at diagnosis than the 222 patients who did not (51.5 vs 64.0 years, two-sided P < .001). BRAF V600E genotype was more prevalent in ever-users than in nonusers (42.9% vs 28.3%, two-sided P = .04) and higher in ever-users who initiated indoor tanning prior to age 25 years compared with age 25 years or older (62.2% vs 31.1%, two-sided P = .003). There were more melanomas in intermittently sun-exposed skin in ever-users than nonusers (65.7% vs 51.9%, respectively, two-sided P = .02). Our data suggest indoor tanning may promote melanomas that arise in skin with low-chronic sun-induced damage through BRAF V600E-mediated melanomagenesis.

Associations of pigmentary and naevus phenotype with melanoma risk in two populations with comparable ancestry but contrasting levels of ambient sun exposure

BACKGROUND

People at high risk of developing melanoma are usually identified by pigmentary and naevus phenotypes.

OBJECTIVE

We examined whether associations of these phenotypes with melanoma risk differed by ambient sun exposure or participant characteristics in two population-based, case-control studies with comparable ancestry but different ambient sun exposure.

METHODS

Data were analysed from 616 cases and 496 controls from the Australian Melanoma Family Study and 2012 cases and 504 controls from the Leeds (UK) case-control study. Questionnaire, interview and dermatological skin examination data were collected using the same measurement protocols. Relative risks were estimated as odds ratios using unconditional logistic regression, adjusted for potential confounders.

RESULTS

Hair and skin colour were the strongest pigmentary phenotype risk factors. All associations of pigmentary phenotype with melanoma risk were similar across countries. The median number of clinically assessed naevi was approximately three times higher in Australia than Leeds, but the relative risks for melanoma associated with each additional common or dysplastic naevus were higher for Leeds than Australia, especially for naevi on the upper and lower limbs. Higher naevus counts on the head and neck were associated with a stronger relative risk for melanoma for women than men. The two countries had similar relative risks for melanoma based on self-reported naevus density categories, but personal perceptions of naevus number differed by country. There was no consistent evidence of interactions between phenotypes on risk.

CONCLUSIONS

Classifying people at high risk of melanoma based on their number of naevi should ideally take into account their country of residence, type of counts (clinical or self-reported), body site on which the naevus counts are measured and sex. The presence of naevi may be a stronger indicator of a genetic predisposition in the UK than in Australia based on less opportunity for sun exposure to influence naevus development.

Is there a causal relationship between vitamin D and melanoma risk? A Mendelian randomization study

BACKGROUND

Several preclinical studies have identified the antiproliferative effects of 25-hydroxyvitamin D [25(OH)D; vitamin D]. Ultraviolet radiation (UVR) is essential for vitamin D synthesis yet increases the risk of melanoma. Observational studies on the association of vitamin D levels with melanoma risk have reported inconclusive results, and are difficult to interpret owing to the potential confounding from the dual role of UVR.

OBJECTIVES

To determine whether there is a causal association between genetically predicted 25(OH)D concentrations and melanoma using a Mendelian randomization (MR) approach.

METHODS

We performed MR using summary data from a large genome-wide association study (GWAS) meta-analysis of melanoma risk, consisting of 12 874 cases and 23 203 controls. Five single nucleotide polymorphisms associated with 25(OH)D concentration - rs12785878, rs10741657, rs2282679, rs6013897 and rs116970203 - were selected as instrumental variables. An inverse variance weighted method was used to access the evidence for causality. MR results from the melanoma meta-analysis were combined with results from an MR study based on a melanoma risk GWAS using UK Biobank data.

RESULTS

A 20 nmol L^-1 decrease in 25(OH)D was not associated with melanoma risk [odds ratio (OR) 1·06, 95% confidence interval (CI) 0·95-1·19]. Results from the UK Biobank were concordant with this, with meta-analysis of our and UK Biobank-derived MR causal estimates showing no association (OR 1·02, 95% CI 0·92-1·13 for a 20 nmol L^-1 decrease).

CONCLUSIONS

The results suggest that vitamin D levels may not be causally associated with the risk of melanoma. What's already known about this topic? Antitumour activity of vitamin D has been identified in preclinical studies. Observational studies link vitamin D deficiency with an increased risk of a range of cancers. There is a growing public interest for vitamin D supplementation. Observational studies of melanoma are fraught with difficulties because while higher ultraviolet radiation levels increase vitamin D levels, such exposure is also associated with increased melanoma risk. Results from observational studies are inconclusive regarding the effect of vitamin D on melanoma risk. What does this study add? Using Mendelian randomization, an approach to causal inference, which is analogous to a natural randomized controlled trial, we found no causal association between vitamin D levels and melanoma.

Prevalence and determinants of sunbed use in thirty European countries: data from the Euromelanoma skin cancer prevention campaign

BACKGROUND

Although considered as a first-group carcinogen, indoor tanning is a common practice in Europe. Euromelanoma is a pan-European skin cancer prevention campaign.

OBJECTIVES

To compare several European countries in terms of the prevalence and determinants of sunbed use.

METHODS

Participants in the Euromelanoma campaigns filled in questionnaires containing demographics and risk factors, including type/duration of sunbed use. Multivariate analyses adjusted for age, gender, education, skin type and year of survey were employed to assess factors independently associated with sunbed use in each country.

RESULTS

In total, 227 888 individuals (67.4% females, median age 44, 63.4% highly educated, 71.9% skin types III-VI) from 30 countries participated. Overall, the prevalence of sunbed ever use was 10.6% (≤19-year-olds: 5.9%; 20 to 35-year-olds: 17.0%; >35-year-olds: 8.3%). Females displayed a higher prevalence than males in all countries. Balkan countries displayed the highest female/male ratios (≥4). Sunbed use was significantly more prevalent among skin type III-VI (14/30 countries) and highly educated participants (11/30 countries). Significant correlations were found between sunbed use prevalence and countries' latitude (P < 0.001) and sunshine (P = 0.002); Italy and Spain represented exceptions towards excessive exposure. Very different prevalence rates were found for Spain (19.3%) and Portugal (2.0%). Scandinavian countries ranked highest in sunbed use among ≤19-year-olds, Baltic countries among 20 to 35-year-olds.

CONCLUSIONS

Sunbed use prevalence was higher in northern, sun-deprived countries, with the exception of Italy and Spain. The main determinants of sunbed use were age (young adults) and gender (females), whereas education and skin type had a less relevant effect. Geographic particularities were found in four regions: Iberian (prevalence ten times higher in Spain than Portugal), Balkan (prevalence disproportionately higher among women), Baltic (highest prevalence among young adults) and Scandinavian (highest prevalence among adolescents). These data have public health relevance for future interventions aimed at reducing sunbed use in Europe.

Association of sunbed use with skin cancer risk factors in Europe: an investigation within the Euromelanoma skin cancer prevention campaign

INTRODUCTION

Sunbed use has been significantly associated with increased risk of melanoma and non-melanoma skin cancer (NMSC), but its relationship with melanoma's risk factors such as high nevus count, atypical nevi and lentigines is poorly studied. Euromelanoma is a skin cancer prevention campaign conducted all over Europe. It offers a once-a-year screening during which participants' data, including sunbed use and phenotype, are collected via questionnaires.

OBJECTIVES

To investigate the association of sunbed use with nevus count, atypical nevi, lentigines and suspicion of skin cancer.

METHODS

To ensure reliability of the data, we defined inclusion and exclusion criteria for countries' eligibility for the risk analysis. Multivariate logistic regression models (including age, gender, education, skin type, family history of melanoma, personal history of skin cancer, any sun exposure and any sunscreen use) were used to calculate summary odds ratios (SORs) of each clinical endpoint for ever sunbed use.

RESULTS

Overall, 227 888 individuals from 30 countries completed the Euromelanoma questionnaire. After the data quality check, 16 countries were eligible for the multivariate analysis, for a total of 145 980 participants (64.8% females; median age 43 years; 62.3% highly educated; 28.5% skin type I-II; 11.0% ever sunbed use). Ever sunbed use was independently associated with nevus count >50 [SOR = 1.05 (1.01-1.10)], atypical nevi [SOR = 1.04 (1.00-1.09)], lentigines [SOR = 1.16 (1.04-1.29)] and suspicion of melanoma [SOR = 1.13 (1.00-1.27)]. Conversely, no significant association was found between ever sunbed use and suspicion of NMSC [SOR = 1.00 (0.91-1.10)].

CONCLUSIONS

Indoor tanning is significantly associated with well-recognized risk factors for melanoma (including high nevus count, presence of atypical nevi and lentigines) as well as suspicion of melanoma within the Euromelanoma screenees. In order to reduce the prevalence of melanoma risk factors, avoidance/discontinuation of sunbed use should always be encouraged, especially but not exclusively for individuals with high-risk phenotypes.

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

The International Agency for Research on Cancer classified, in July 2009, exposure to artificial tanning devices (sunbeds) as carcinogenic to humans. This classification was based on evidence from epidemiological and experimental animal studies. The present chapter will review these epidemiological evidences. The summary risk estimates from 27 epidemiological studies obtained through a meta-analysis showed an increased risk of melanoma: summary relative risk (SRR) = 1.20 [95% confidence interval (CI) 1.08-1.34]. The risk was higher when exposure took place at younger age (SRR = 1.59; 95% CI 1.36-1.85). The risk was independent of skin sensitivity or population and a dose response was evident. A meta-analysis of 12 studies was conducted for non-melanoma skin cancers and showed a significantly increased risk for basal cell carcinoma (SRR = 1.29; 95% CI 1.08-1.53) and for squamous cell carcinoma (SRR = 1.67; 95% CI 1.29-2.17). As for melanoma, the risk for other skin cancers increased for first exposures at young age. Epidemiological studies have gradually strengthened the evidence for a causal relationship between indoor tanning and skin cancer and they fit with prior knowledge on relationship between UV exposure and skin cancer. Additionally, several case-control studies provided consistent evidence of a positive association between use of sunbed and ocular melanoma, also with greater risk for first exposures at younger age. Preventive measures based on information on risk or by requiring parental authorization for young users proved to be inefficient in several studies. The significant impact of strong actions or total ban, such as performed in Iceland, or a total ban of sunbed use, as in Brazil or Australian states, needs to be further assessed.

Incidence, Mortality, and Spatiotemporal Distribution of Cutaneous Malignant Melanoma Cases Across Canada

Background:

We recently reported a steady increase in the incidence and mortality of cutaneous malignant melanoma (CMM) in Canada during 1992-2010.

Objectives:

The objective of this article is to examine the distribution of Canadian CMM patients at the level of provinces, cities, and forward sortation area (FSA) postal codes.

Methods:

Using 3 Canadian population-based registries, we conducted an in-depth examination of the incidence and mortality trends for 72 565 Canadian CMM patients over the period 1992-2010.

Results:

We found that among 20- to 39-year-olds, the incidence of CMM in women (7.17 per 100 000 individuals) was significantly higher than in men (4.60 per 100 000 individuals per year). Women age 80 years and older had an incidence of CMM (58.46 cases per 100 000 women per year) more than 4 times greater than the national average (12.29 cases per 100 000 population per year) and a corresponding high mortality rate (20.18 deaths per 100 000 women per year), when compared with the Canadian melanoma mortality of 2.4 deaths per 100 000 per year. In other age groups men had higher incidence and corresponding melanoma mortality rates. We also studied CMM incidence by province, city, and FSA postal codes and identified several high-incidence communities that were located near the coast/waterfronts. In addition, plotting latitude measures for cities and FSAs vs CMM incidence rate confirmed the inverse relationship between geographical latitude and incidence of melanoma in Canada (slope = –0.22 ± 0.05).

Conclusions:

This research may help develop sex-, age- and geographic region-specific recommendations to decrease the future burden of CMM in Canada.

Skin cancer projections and cost savings 2014-2045 of improvements to the Danish sunbed legislation of 2014

BACKGROUND

Sunbed use increases the risk of skin cancer. The Danish sunbed legislation (2014) did not include an age limit.

AIM

To model skin cancer incidences and saved costs from potential effects of structural interventions on prevalence of sunbed use.

MATERIALS AND METHODS

Survey data from 2015 were collected for 3999 Danes, representative for the Danish population in regards to age, gender and region. Skin cancer incidences were modelled in the Prevent program, using population projections, historic cancer incidence, sunbed use exposure and relative risk of sunbed use on melanoma.

RESULTS

If structural interventions like an age limit of 18 years for sunbed use or complete ban had been included in the Danish sunbed legislation in 2014, it would have reduced the annual number of skin cancer cases with 455 or 4177, respectively, while for the entire period, 2014-2045 the total reductions would be 3730 or 81 887 fewer cases, respectively. The cost savings from an age limit or ban, respectively, are 9 and 129 millions € during 2014-2045.

CONCLUSION

Legislative restrictive measures which could reduce the sunbed use exists. Danish politicians have the opportunity, supported by the population, to reduce the skin cancer incidence and thereby to reduce the future costs of skin cancer.

Reproductive factors, exogenous hormone use and incidence of melanoma among women in the United States

Background

Although the photosensitising effects of oestrogens may increase the impact of ultraviolet radiation (UVR) on melanoma risk, few prospective studies have comprehensively assessed the association between oestrogen-related factors and melanoma.

Methods

We examined the associations between reproductive factors, exogenous oestrogen use and first primary invasive melanoma among 167 503 non-Hispanic white, postmenopausal women in the NIH-AARP Diet and Health Study. Satellite-based ambient UVR estimates were linked to geocoded residential locations of participants at study baseline.

Results

Increased risk of melanoma was associated with early age at menarche (≤10 vs ≥15 years: HR = 1.25, 95% CI: 0.92, 1.71; P for trend = 0.04) and late age at menopause (≥50 vs <45 years: HR = 1.34, 95% CI: 1.13, 1.59; P for trend = 0.001). The relationship between ambient UVR and melanoma risk was highest among women with age at menarche ≤10 years (HR per UVR quartile increase = 1.29; 95% CI: 1.05, 1.58; P-interaction = 0.02). Melanoma risk was not associated with parity, age at first birth, use of oral contraceptives or use of menopausal hormone therapy.

Conclusions

Our findings suggest that increased melanoma risk is associated with early age at menarche and late age at menopause. Effect modification findings support the hypothesis that endogenous oestrogen exposure in childhood increases photocarcinogenicity. Future studies should include information on personal UVR exposure and sun sensitivity.

Beliefs, attitudes and perceptions to sun-tanning behaviour in the Norwegian population: a cross-sectional study using the health belief model

BACKGROUND

Norway has one of the highest incidences of melanoma in the world. It has been suggested that the majority of all skin cancers could be prevented by changes related to sun-tanning behaviour. This study explores the sun-tanning behaviour of the Norwegian population using a modified Health Belief Model (HBM). Increased knowledge about beliefs, attitudes and sun-tanning behaviour can provide information which may be useful for future sun protection interventions.

METHODS

In 2017, 1004 members of the Norwegian population completed cross-sectional online surveys. People who seek the sun for tanning purposes was the eligibility criterion for this study, reducing the study population to 569. With the aid of the constructs from the HBM, predictive factors explaining sun-tanning behaviour were determined using multivariate linear regression adjusted for demographics (gender, age, education and income). Furthermore, the predictor variables, empowerment and benefits of tanning, were added to the model.

RESULTS

Five of the constructs in the modified HBM showed significant correlation with sun-tanning behaviour using bivariate analysis. The strongest correlation was perceived barriers of sun protection (0.42), with the next strongest being the benefits of tanning (0.30). The modified model explained 31% of the variation in sun-tanning behaviour using multivariate analysis. Significant predictors from the HBM to sun-tanning behaviour were perceived barriers to sun protection (Beta = 0.36, p < 0.001) and the severity of melanoma (Beta = - 0.20, p < 0.001). In addition, empowerment (Beta = 0.05, p = 0.05) and the benefits of tanning (Beta = 0.28, p < 0.001) proved to be variables with significant effect on sun-tanning behaviour. The demographic factors age, education and income were also associated with sun-tanning behaviour (p < 0.05).

CONCLUSION

Based on the results of this study, several factors in the modified HBM had a significant impact on Norwegians' sun-tanning behaviour. The results indicate that future sun protection interventions should focus on reducing barriers in relation to sun protection behaviour, as well as emphasizing the severity of adverse tanning behaviour and melanoma. Efforts to alter the perceptions of the beneficial factors of tanning behaviour can also be appropriate in health promotion campaigns and interventions. Finally, implementing empowerment strategies could have a positive effect on promoting healthy sun-tanning behaviour.

Cutaneous malignant melanoma incidence and mortality trends in Canada: A comprehensive population-based study

BACKGROUND

The incidence of cutaneous malignant melanoma (CMM) is on the rise in many parts of the world. However, there is limited knowledge on the epidemiology of CMM in Canada.

OBJECTIVE

To conduct a comprehensive population-based study of CMM in Canada.

METHODS

We examined patient clinical and pathologic characteristics as well as the incidence and mortality trends of CMM in Canada using 3 independent population-based registries.

RESULTS

In total, 72,565 Canadian patients were given CMM diagnoses during 1992-2010; 47.5% were women. Average age at the time of diagnosis was 56.5 years for women and 60.4 years for men. We report a steady increase in CMM incidence and mortality rates in both sexes. The overall incidence rate of CMM in Canada was 12.29 cases/100,000 person-years. We also report important differences in the incidence and mortality rates between Canadian provinces and territories; the highest incidence of this cancer was documented in Nova Scotia and Prince Edward Island.

LIMITATIONS

Data on race, clinical disease stage, and Breslow depth of CMM was not available.

CONCLUSION

This study, for the first time, defines the disease burden of CMM in Canada and highlights important longitudinal, geographic, and spatial differences in the distribution of CMM in this country.

Clinicopathologic, misdiagnosis, and survival differences between clinically amelanotic melanomas and pigmented melanomas

BACKGROUND

Amelanotic malignant melanoma (AMM) is challenging to diagnose. Clinical risk factors for AMM are not well defined.

OBJECTIVE

To investigate clinicopathologic, misdiagnosis, and survival differences between patients with AMM and those with pigmented malignant melanoma (PMM).

METHODS

A cross-sectional retrospective medical record review at a tertiary academic medical center.

RESULTS

A total of 933 patients with melanoma with known presenting tumor color were identified (342 with AMM vs 591 with PMM). AMM was associated with older age, history of nonmelanoma skin cancer, and red hair, whereas AMM was inversely associated with a family history of melanoma, more than 50 nevi, and a history of dysplastic nevi. Compared with PMM, AMM was more likely to be located on the head and/or neck, had more aggressive pathologic features (greater Breslow depth and/or mitoses, ulceration, nodular subtype), and was less likely to be associated with a precursor nevus or regression. Finally, patients with AMM were more likely to be misdiagnosed than were patients with PMM (25% vs 12% clinically and 12% vs 7% pathologically), and they had poorer melanoma-specific survival (5-year overall survival rate, 0.77 [95% confidence interval, 0.72-0.82] vs 0.84 [95% confidence interval, 0.80-0.87]).

LIMITATIONS

Retrospective study design, single-institutional study.

CONCLUSION

Greater clinician awareness, lower biopsy thresholds, and increased patient education may be useful to enhance AMM detection in patients with certain characteristics.

Association of Phenotypic Characteristics and UV Radiation Exposure With Risk of Melanoma on Different Body Sites

Importance

Two pathways have been hypothesized for the development of cutaneous melanoma: one typically affects the head and neck, a site with chronic sun damage, and the other affects the trunk, which is less exposed to the sun. However, the possible cause of limb melanomas is less studied under this hypothesis.

Objective

To investigate the association between phenotypic characteristics, pattern of UV radiation exposure, and risk of melanoma on different body sites.

Design, Setting, and Participants

This study used data on 161 540 women with information on phenotypic characteristics and UV radiation exposure who were part of the Norwegian Women and Cancer study, a population-based prospective study established in 1991 with exposure information collected by questionnaires at baseline and every 4 to 6 years during follow-up through 2015. Data analysis was performed from October 2017 through May 2018.

Exposures

Participants reported hair color, eye color, untanned skin color, number of small symmetric and large asymmetric nevi, and freckling, as well as histories of sunburns, sunbathing vacations, and indoor tanning in childhood, adolescence, and adulthood.

Main Outcomes and Measures

The Norwegian Women and Cancer study was linked to the Cancer Registry of Norway for data on cancer diagnosis and date of death or emigration. Primary melanoma site was categorized as head and neck, trunk, upper limbs, and lower limbs.

Results

During follow-up of the 161 540 women in the study (mean age at study entry, 50 years [range, 34-70 years]; mean age at diagnosis, 60 years [range, 34-87 years]), 1374 incident cases of melanoma were diagnosed. Having large asymmetric nevi was a significant risk factor for all sites and was strongest for the lower limbs (relative risk [RR], 3.38; 95% CI, 2.62-4.38) and weakest for the upper limbs (RR, 1.96; 95% CI, 1.22-3.17; P = .02 for heterogeneity). Mean lifetime number of sunbathing vacations was significantly associated with risk of trunk melanomas (RR, 1.14; 95% CI, 1.07-1.22) and lower limb melanomas (RR, 1.12; 95% CI, 1.05-1.19) but not upper limb melanomas (RR, 0.98; 95% CI, 0.88-1.09) and head and neck melanomas (RR, 0.87; 95% CI, 0.73-1.04; P = .006 for heterogeneity). Indoor tanning was associated only with trunk melanomas (RR for the highest tertile, 1.49; 95% CI, 1.16-1.92) and lower limb melanomas (RR for the highest tertile, 1.33; 95% CI, 1.00-1.76; P = .002 for heterogeneity). Skin color, hair color, small symmetric nevi, and history of sunburns were associated with risk of melanoma on all sites.

Conclusions and Relevance

These results appear to support the hypothesis of divergent pathways to melanoma and that recreational sun exposure and indoor tanning are associated with melanoma on the lower limbs, the most common site of melanoma in women. These findings appear to have important preventive implications.

Development in sunburn 2007-2015 and skin cancer projections 2007-2040 of campaign results in the Danish population

Exposure to ultraviolet radiation is the main risk factor for skin cancer. Denmark has one of the highest incidences of skin cancer in the world. In 2007, a long-term sun safety campaign was launched in Denmark. We have evaluated the effects on prevalence of sunburn and modeled the effects on future melanoma incidence.Sunburn was evaluated by annual cross-sectional surveys representative for the Danish population on age, gender, and region. During 2007-2015, survey data were collected for 33.315 Danes. Cutaneous Melanoma incidences were modeled in the Prevent program, using population projections, historic incidence, sunburn exposure, and relative risk of sunburn on melanoma.The prevalence of sunburn in Denmark was reduced with 1% annually during 2007 to 2015. The campaign is estimated to have reduced the number of skin cancer cases with 664 annually in 2040 and 14.326 totally during 2007 to 2040. If the campaign was terminated in 2015 and sunburn rates return to precampaign level there would be no annual reduction in 2040 while in total the reduction would be 4.024 cases for 2007 to 2040. A continuous campaign until 2040 would yield annual reductions of 2.121 cases by 2040 and a total of 29.729 cases for the entire period.We have showed the value of prevention and the value of long-term planning in prevention campaigning. Sunburn use was reduced significantly during 2007-2015 and further reductions are possible. Consequently, we predict significant fewer skin cancer cases as anticipated.

Sunbed use 2007-2015 and skin cancer projections of campaign results 2007-2040 in the Danish population: repeated cross-sectional surveys

OBJECTIVE

To evaluate the effect of the Danish Sun Safety Campaign 2007-2015 on the prevalence of sunbed use and to model future effects on the skin cancer incidences 2007-2040.

DESIGN

The study has a repeated, cross-sectional design.

SETTING

Exposure to ultraviolet radiation is the main risk factor for skin cancer. Denmark has the highest prevalence of sunbed use reported and one of the highest incidences of skin cancer worldwide.

PARTICIPANTS

During 2007-2015, survey data were collected for 37 766 Danes, representative of the Danish population with regards to age, gender and region.

INTERVENTIONS

In 2007, an ongoing long-term antisunbed campaign was launched in Denmark.

PRIMARY AND SECONDARY OUTCOME MEASURES

Sunbed use was evaluated by annual cross-sectional surveys. Skin cancer incidence was modelled in the Prevent programme, using population projections, historic cancer incidence, sunbed use exposure and relative risk of sunbed use on melanoma.

RESULTS

The prevalence of recent sunbed use in Denmark was reduced from 32% and 18% to 13% and 8% for women and men, respectively. The campaigns results during 2007-2015 are estimated to reduce the number of skin cancer cases from more than 5000 (746malignant melanoma, 1562 SCC, 2673 BCC) totally during 2007-2040. Keeping the 2015 level of sunbed use constant by continued campaign pressure or introduction of structural interventions would potentially prevent more than 750 skin cancer cases annually in 2040 and 16 000 skin cancer cases in total during 2007-2040.

CONCLUSION

We have shown the value of prevention and of long-term planning in prevention campaigning. Sunbed use was reduced significantly during 2007-2015 and further reductions are possible by structural interventions. Consequently, significantly fewer skin cancer cases are anticipated during 2007-2040. The Danish Parliament has population support to enforce structural interventions to avoid a large burden of this disease.

The health benefits of UV radiation exposure through vitamin D production or non-vitamin D pathways. Blood pressure and cardiovascular disease

The detrimental effects of ultraviolet radiation are well known. Skin cancer, photo-aging, and induction or exacerbation of photosensitive dermatoses have been the focus of most photobiological research since 1928 when Findlay confirmed the carcinogenicity of ultraviolet radiation using a murine model of skin cancer. The epidemiological, mechanistic and clinical trial data have enabled the classification by the International Agency for Research on Cancer of ultraviolet radiation as a Group 1 ('sufficient evidence') carcinogen for human skin. Public health advice in most developed countries with a pale-skinned population following this has advocated limiting exposure to sunlight through use of clothing, sunblock and behavioural alterations. Despite this plethora of data, one striking omission is evidence that ultraviolet radiation shortens life, and as I will lay out in this chapter, epidemiological and now mechanistic data suggest that UV may have significant benefits on health and in particular cardiovascular health.

UV Driven Tanning Salons: Danger on Main Street

Appearing in the early 1980s, at a time when UVA was considered as relatively safe, the tanning industry has substantially developed in occidental countries, especially in Northern European countries. In Europe, the erythemally-weighted irradiance of a modern sunbed should not exceed 0.3 W/m², equivalent to an UV index of 12, i.e. to a tropical midday sun, but increased in recent years, the UV spectrum emitted by sunbeds had evolved towards higher UVA irradiance and solariums UV had become even less similar to natural sun.

Polyunsaturated fatty acids and risk of melanoma: A Mendelian randomisation analysis

Melanoma is the deadliest form of skin cancer, mainly affecting populations of European ancestry. Some observational studies suggest that particular diets reduce melanoma risk, putatively through an increase in polyunsaturated fatty acid (PUFA) consumption. However, interpretation of these observational findings is difficult due to residual confounding or reverse causality. To date, a randomized controlled trial has not been carried out to examine the relationship between PUFAs and melanoma. Hence, we performed a Mendelian randomisation (MR) study to evaluate the link between PUFAs and melanoma. To perform MR, we used summary results from the largest risk genome-wide association study (GWAS) meta-analysis of melanoma, consisting of 12,874 cases and 23,203 controls. As instrumental variables we selected SNPs associated with PUFA levels from a GWAS meta-analysis of PUFA levels, from the CHARGE consortium. We used the inverse variance weighted method to estimate a causal odds ratio. To aid interpretation, we established a benchmark "large" predicted change in PUFAs in which, for example, an increase in docosahexaenoic acid (DPA) of 0.17 units (equal to 1 standard deviation) moves a person from the 17^th percentile to the median. Raising PUFA levels by a large amount (increasing DPA by 0.17 units) only negligibly changed melanoma risk: odds ratio [OR] = 1.03 (95% confidence interval [CI] = 0.96-1.10). Other PUFAs yielded similar results as DPA. Our MR analysis suggests that the effect of PUFA levels on melanoma risk is either zero or very small.

Counseling on Sun Protection and Indoor Tanning

BACKGROUND

The US Preventive Services Task Force recommends clinical counseling for individuals ages 10 to 24 years to decrease skin cancer risk.

METHODS

A national, random sample of US American Academy of Pediatrics members practicing primary care in 2002 (response rate 55%) and 2015 (response rate 43%). Surveys explored attitudes and experiences regarding sun protection counseling; indoor tanning questions were added in 2015. χ² tests compared demographics and counseling responses across years, and multivariable logistic regression models examined counseling predictors.

RESULTS

More pediatricians in 2015 (34%) than in 2002 (23%) reported discussing sun protection during recent summer months with ≥75% of patients. This pattern held across all patient age groups (each P <.001). Female and suburban pediatricians counseled more; those in the South and West counseled less. More pediatricians in 2015 than in 2002 named time as a barrier. Sun protection ranked lowest among preventive topics in both years. In 2015, approximately one-third of pediatricians reported discussing indoor tanning at least once with 10 to 13 year-old patients; approximately half discussed this with older adolescents. Most (70%) did not know if their states had laws on minors' indoor tanning access; those stating they knew whether a law existed counseled more.

CONCLUSIONS

Although improved, sun protection counseling rates remain low. Indoor tanning counseling can be improved. Because early-life exposure to UV radiation increases risk and clinician counseling can positively impact prevention behaviors, pediatricians have an important role in skin cancer prevention; counseling may save lives. Time constraints remain a barrier.

Recall of indoor tanning salon warnings and safety guidelines among a national sample of tanners

Indoor tanning (IT) is a known carcinogen, and regulation has increased across the USA. However, there is minimal point-of-sale regulation for adult users. The purpose of the present study is to explore whether IT users recall being provided with warnings or safety guidelines at tanning salons. A national sample of 273 young adult, female IT users (mean age = 22.26, SD = 2.38) was surveyed regarding the frequency that they recalled being provided with six different warnings and safety guidelines when at tanning salons. Between 65 and 90.1 % of participants reported recalling the various warnings and guidelines. Having very fair skin was reported by 16.8 % of participants, and these high-risk individuals were less likely to recall having read and signed a consent form than other IT users (p = .002). The current level of regulation is insufficient to provide IT users with consistent warnings and safety guidelines at tanning salons.

A protocol for prospective studies of 25-hydroxyvitamin D, leptin and body mass index in relation to cutaneous melanoma incidence and survival

INTRODUCTION

The incidence and mortality rates of cutaneous melanoma (CM) are increasing among fair-skinned populations worldwide. Ultraviolet radiation (UVR) is the principal risk factor for CM, but is also the main source of 25-hydroxyvitamin D (25(OH)D), which has been associated with reduced risk and better prognosis of some cancer types. However, both low and high 25(OH)D levels have been associated with increased risk of CM. Obesity as measured by body mass index (BMI) is associated with risk of several cancers and has also been suggested as a risk factor for CM, and may also be related to insufficient 25(OH)D and/or high leptin levels. Moreover, contracting a CM diagnosis has been associated with increased risk of developing second cancer. We aim to study whether low prediagnostic serum levels of 25(OH)D, high prediagnostic levels of BMI and high serum leptin levels influence CM incidence, Breslow thickness and CM mortality, and risk of second cancer and survival after a CM diagnosis.

METHODS AND ANALYSIS

Cohort and nested case-control studies will be carried out using the population-based Janus Serum Bank Cohort (archival prediagnostic sera, BMI, smoking and physical activity), with follow-up from 1972 to 2014. Additional data will be received from the Cancer Registry of Norway, the national Cause of Death Registry, Statistics Norway (education and occupation) and exposure matrices of UVR. Time-to-event regression models will be used to analyse the cohort data, while the nested case-control studies will be analysed by conditional logistic regression. A multilevel approach will be applied when incorporating group-level data.

ETHICS AND DISSEMINATION

The project is approved by the Regional Committee for Medical Research Ethics and is funded by the Norwegian Cancer Society. Results will be published in peer-reviewed journals, at scientific conferences and in the news media.

Knowledge deficit, attitude and behavior scales association to objective measures of sun exposure and sunburn in a Danish population based sample

The objective of this study was to develop new scales measuring knowledge and attitude about UVR and sun related behavior, and to examine their association to sun related behavior objectively measured by personal dosimetry. During May-August 2013, 664 Danes wore a personal electronic UV-dosimeter for one week that measured their UVR exposure. Afterwards, they answered a questionnaire on sun-related items. We applied descriptive analysis, linear and logistic regression analysis to evaluate the associations between the questionnaire scales and objective UVR measures. Perceiving protection as routine and important were positively correlated with protective behavior. Knowledge deficit of UV and risk of melanoma, perceived benefits and importance of protection behavior was also correlated with use of protection. ‘Knowledge deficit of UV and risk of melanoma and Perceived barrier towards sun avoidance between 12 and 15’ were both associated with increased risk of sunburn. Attitude towards tan was associated to both outdoor time and exposure as well as use of protection, but not to sunburn. The results regarding Knowledge deficit of UV and risk of melanoma associated to UVR exposure and Perceived barrier towards sun avoidance between 12 and 15 emphasize the importance of awareness of melanoma risk and the priority of the skin cancer prevention advice. Shifting activities to outside the suns peak-hours could be an approach for structural and campaign preventive measures. Knowledge of items predicting exposure to UVR, use of protection and sunburn are important for planning of preventive interventions and melanoma research.

Fasting boosts sensitivity of human skin melanoma to cisplatin-induced cell death

Melanoma is one of leading cause of tumor death worldwide. Anti-cancer strategy includes combination of different chemo-therapeutic agents as well as radiation; however these treatments have limited efficacy and induce significant toxic effects on healthy cells. One of most promising novel therapeutic approach to cancer therapy is the combination of anti-cancer drugs with calorie restriction. Here we investigated the effect Cisplatin (CDDP), one of the most potent chemotherapeutic agent used to treat tumors, in association with fasting in wild type and mutated BRAFV600E melanoma cell lines. Here we show that nutrient deprivation can consistently enhance the sensitivity of tumor cells to cell death induction by CDDP, also of those malignancies particularly resistant to any treatment, such as oncogenic BRAF melanomas. Mechanistic studies revealed that the combined therapy induced cell death is characterized by ROS accumulation and ATF4 in the absence of ER-stress. In addition, we show that autophagy is not involved in the enhanced sensitivity of melanoma cells to combined CDDP/EBSS-induced apoptosis. While, the exposure to 2-DG further enhanced the apoptotic rate observed in SK Mel 28 cells upon treatment with both CDDP and EBSS.