Getting in early: primary skin cancer prevention at 55 German kindergartens

Photoprotection: Current developments and controversies

This review aimed at summarizing some of the key points that were discussed during the photoprotection session at the International Forum of Dermatology in 2022. This international conference was designed to address prominent topics of clinical dermatology in a holistic way, allowing to articulate multiple viewpoints. Therefore, this review does not claim to be exhaustive, but is instead intended to give an overview of recent developments and ongoing controversies in the field of photoprotection. Cumulative ultraviolet radiation (UVR) exposure is the major aetiological factor in the development of photoageing, photoimunosuppression and photocarcinogenesis. UVA (320-400 nm) penetrates into the dermis and damages DNA and other intracellular and acellular targets primarily by generating reactive oxygen species (ROS). It is the major contributor to photoageing, characterized by fine and coarse wrinkles, dyspigmentation and loss of elasticity. UVB (290-320 nm) is responsible for sunburns through direct damage to DNA by the formation of 6-4 cyclobutane pyrimidine dimers (CPDs) and pyrimidine 6-4 pyrimidone photoproducts. Both UVA and UVB exposure increase the risk of basal cell carcinoma, squamous cell carcinoma and melanoma. In recent years, visible light (VL; 400-700 nm) has also been implicated in the exacerbation of conditions aggravated by sun exposure such as hyperpigmentation and melasma. Photoprotection is a critical health strategy to reduce the deleterious effects of UVR and VL. Comprehensive photoprotection strategies include staying in the shade when outdoors, wearing photoprotective clothing including a wide-brimmed hat, and sunglasses, and the use of sunscreen. Due to the absorption of UV filters, the safety of sunscreens has been questioned. Newer sunscreens are becoming available with filters with absorption even beyond the UV spectrum, offering enhanced protection compared with older products. Prevention of photocarcinogenesis, sun-induced or sunlight-exacerbated hyperpigmentary conditions and drug-induced photosensitivity is an important reason for adopting comprehensive photoprotection strategies.

Use of multiple correspondence analysis to explore associations between caregivers and sun protective habits during summer vacations

BACKGROUND

Childhood exposure to ultraviolet radiation (UVR) plays an important role in the development of keratinocyte carcinomas and melanomas. Therefore, sun protective measures ought to be implemented during early childhood. Young children are largely dependent upon adult care providers in order to achieve proper sun protection.

OBJECTIVES

To develop effective photoprotection in children, it is necessary to understand caregivers' attitudes and knowledge about UVR exposure. This study aimed to explore the variables associated with sun protective behaviour in parents and grandparents during summer vacations.

METHODS

A multinational, cross-sectional study was conducted using a web-based online survey with a representative sample of parents and grandparents of children aged ≤ 12 years, who cared for their children/grandchildren for at least 2 weeks during the summer of 2021, in five countries (France, Germany, Spain, Italy and the USA). Multiple correspondence analysis (MCA) was used to explore in an unbiased way the possible relationships among all the variables and to identify specific profiles.

RESULTS

A total of 6190 adult participants responded to the questionnaire: 5104 parents (average age 42.0 years, 54.3% women) and 1086 grandparents (average age 64.2 years, 55.5% women). MCA allowed discrimination of two groups of respondents based on their answers: a profile with 'unprotected sun exposure habits' vs. those with 'protective sun exposure habits'. Parents fell in closer proximity to the 'unprotected sun exposure habits', and 'sunburn reported in youngest child'. Grandparents adopted more cautious behaviours than parents. Nevertheless, grandparents fell in proximity to 'having exposed the grandchild to the sun between 11 h and 17.00 h', 'not using an umbrella' and 'not using sunglasses'.

CONCLUSIONS

Although grandparents appear to adopt more cautious behaviours than parents, many gaps in proper sun protection behaviour were observed in both groups of caregivers.

The role of community pharmacists in primary and secondary prevention of skin cancer: an evaluation of a Flemish skin cancer prevention campaign

BACKGROUND

Skin cancer is a leading form of cancer in Belgium. Prevention of skin cancer by community pharmacists can play a role in increasing awareness and promoting sun protection. However, which persons could be reached by community pharmacists for skin cancer awareness in Belgium and whether this increased awareness is associated with increased sun protection and early detection remains unclear.

METHODS

Demographics of approached persons in Flemish community pharmacies during the months of May-June 2022 and the content of the skin cancer counseling were retrieved from the pharmacy database. Sunscreen purchases and dermatologist visits were evaluated up to 180 days after the skin cancer counseling.

RESULTS

Community pharmacists provided skin cancer counseling to a broad population of visitors (n = 822, 69% females, median age of 59 years Q1-Q3: 44-71 years). During the campaign, 822 visitors received a leaflet with skin cancer prevalence and sunscreen importance. On top of that, 335 visitors (41%) received additional counseling: skin type sensitivity was checked for 198 visitors (24%), typical characteristics of melanoma were discussed with 100 visitors (12%) and 37 visitors (5%) were referred to a physician for further information or concerns regarding a skin spot. Overall, one out of three visitors purchased sunscreen on the day of the counseling (33%, increasing up to 38% after 180 days). Among people under 20 years, this was even higher (51%). Additional counseling increased the likelihood of a dermatologist visit within 180 days (OR = 1.80; 95%CI: 1.12-2.88).

CONCLUSIONS

By providing skin cancer counseling in Belgian community pharmacies, a broad range of citizens was reached and triggered to purchase sunscreen, often on the same day as the counseling. Notably, young people were likely to purchase sunscreen. Citizens receiving additional counseling were more likely to visit a dermatologist within 180 days.

Encouraging sun protection early in life: from a successful prevention programme in children to the identification of psychological barriers in adolescents

Children and adolescents have high rates of sunburn and high levels of ultraviolet radiation (UVR) exposure and are therefore at risk of developing skin cancer in later life. Minimizing UVR exposure in childhood and adolescence may be the most important component of skin cancer prevention efforts. Thus, age-adapted prevention campaigns, targeting children, adolescents and caregivers, are needed to change sun protection behaviour among individuals in these age groups. In the first part of this review, we describe the 'SunPass' programme, which was initiated in Germany in 2010 as the first nationwide educational intervention for sun safety designed to teach kindergarten children and their caregivers how to protect themselves from overexposure to the sun. Implemented in 55 kindergartens, this programme has been shown to be effective at improving sun protection behaviour (P < 0.001) and hat use (P = 0.029) among kindergarten children, as well as at improving shade practices and increasing demand for protective clothing (P < 0.001). Up to 40 000 children, 50 000 parents/grandparents and 2500 kindergarten caregivers took part in the SunPass programme in Germany from 2019 to June 2021. The programme has also been adapted and implemented in several other European countries and could be readily adapted for use elsewhere. In the second part of this review, we discuss the specific challenges faced by adolescents and consider how these issues may impact their sun protection behaviour. Adolescents have difficulties suppressing responses to reward-related cues and projecting themselves into the future. They also place a lot of importance on social acceptance and cosmetic appearance, and their higher risk of depression, addiction and impulsivity make them vulnerable to tanning addiction. These specificities need to be acknowledged by dermatologists, so they can adapt their therapeutic relationship and develop effective sun protection interventions for this generation.

Skin cancers and their risk factors in older persons: a population-based study

Background

The number of skin cancer is increasing rapidly. However, little is known about the risk factors of skin cancer in older persons. Our objectives were to determine the risk factors for skin cancer or its precursors in an older population. More specifically, to study the association of new skin cancers with previous skin cancer, sex, age, Fitzpatrick’s skin type, history of outdoor work and socioeconomic status (SES).

Methods

In this retrospective cross-sectional study of a large, well documented historical cohort data set a total body skin examination (TBSE) was performed for 552 participants aged between 70 and 93 years by dermatologists. The information gathered was augmented with health register data and self-reported data. The associations between skin cancer and its risk factors were studied by using the logistic regression analyses.

Results

According to the TBSE skin cancer/precursor was present in 25.5% of participants and was more common in males than in females (34.5% vs 20.2%, p < 0.001). Previous skin cancer increased the risk of subsequent skin cancer 2.6-fold (OR 2.56, 95% CI 1.43-4.55) and male sex nearly 2-fold (1.97, 95% CI 1.26-3.08). Specific risk factors for the first occurrence of skin cancer were male sex and outdoor work. There was also association between skin cancer and age and socioeconomic status.

Conclusions

TBSE is recommend for physicians treating older persons to allow early recognition of skin cancers or their precursors. Older males need particularly close attention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02964-1.

The Role of the Global Solar UV Index for Sun Protection of Children in German Kindergartens

More than twenty-five years ago, the Global Solar UV index (UVI) was introduced as a simple means of visualizing the intensity of ultraviolet radiation and to alert people to the need for sun protection. In our survey, among directors of 436 kindergartens in southern Germany we investigated the level of awareness and knowledge about the UVI as well as the practical consequences for sun protection in kindergartens. Less than half of the directors (n = 208, 47.7%) had ever heard of the UVI, and only a small minority of them (n = 34, 8.7%) used the daily UVI information to adapt sun protective measures in their kindergartens. Detailed knowledge about the UVI was a rarity among the respondents. The proportion of respondents with self-perceived detailed UVI knowledge was five times higher than the actual knowledge assessed by an in-depth structured interview using open-ended questions about the UVI (14.2% vs. 2.8%). No clear relationship between UVI awareness, knowledge, and use and directors' age and gender was found. The UVI-related variables also showed no association with directors' knowledge of risk factors for skin cancer and their attitudes towards tanned skin. Overall, the results paint a sobering picture regarding the penetration of the UVI into sun protection policies of German kindergartens. Future public health campaigns should aim to increase the awareness and understanding of the UVI as well as its relevance for sun protection of children.

Results of a Primary Skin-Cancer-Prevention Campaign in Early Childhood on Sun-Related Knowledge and Attitudes in Southern Hungary

Simple Summary

Primary skin-cancer-prevention campaigns among young children are important as this is the age when individuals are developing behaviors. Our aim was to evaluate sun-protection knowledge and behavior among caregivers in daycare centers and kindergartens and to determine if educational lectures are positively influential. In daycare centers, we discovered that measures of sun protection (e.g., hat, sunscreen, and shaded areas) are more likely to be available when compared to kindergartens. Knowledge regarding sun safety has improved following our initial presentation, however, not significantly. Sun safety policies did not exist in any of the facilities, presenting an urgent need for their implementation.

Abstract

Avoidance of ultraviolet (UV) exposure in early childhood is important for reducing the lifetime risk of developing skin cancer. The goal of the present prospective, multicenter pilot study was to assess the sun-protection practices in kindergartens and daycare centers and to evaluate sun protection knowledge and behavior among caregivers employed in the surveyed facilities. The study consisted of two parts. A baseline questionnaire was completed by the caregivers in relation to knowledge regarding basic sun protection and sun protection practices of the participating facilities. Afterward, a thirty-minute presentation was hosted in reference to this topic. Six months following the presentation, a follow-up questionnaire was distributed among the caregivers, evaluating the attitude-related and behavioral changes towards children. A total of 153 caregivers from five daycare centers (children between 6 months and 3 years of age) and sixteen kindergartens (children between 3 and 7 years of age) willfully participated in our study. According to our results, the main source of information regarding sun protection originated from different types of media. We found that staying in shaded areas and the use of protective clothing were not frequent in the facilities. Following our presentation regarding skin types and sunscreen use, protective measures improved, but not significantly (p = 0.222). The majority (92.31%) of caregivers distributed the information throughout their environment and also to parents. Sun protection knowledge is necessary; however, motivation among caregivers and parents and involvement of children is also relevant. Hence, a continuous, repetitive educational program regarding sun-smart behavior is deemed essential.

Cluster Randomized Trial: Sun Protection Intervention 'Clever in Sun and Shade for Preschools'-Effectiveness and Dissemination

Skin cancer is one of the most common types of cancer and UV radiation is one of the main risk factors. Therefore, sun protection, especially in childhood, is strongly recommended. We examined the effectiveness of the ‘Clever in Sun and Shade for Preschools’ program (CLEVER) in promoting sun protection behavior among preschool staff (trial registration: DRKS00023468) and describe its dissemination. Within a cluster randomized trial with 24 preschools (n = 273 staff members) stating a high need for sun protection measures, an educational workshop for preschool staff and a project kit with materials applicable in preschool groups was provided. Staff members of preschools taking part in CLEVER report significantly stronger sun protection behavior to avoid the sun (effect size [ES] 0.70, 95% confidence interval [CI] 0.04 0.71, p < 0.05) and less perceived impediments to avoid the sun (ES −0.56, CI −0.82 −0.17, p < 0.01) after 12 months as well as higher self-efficacy to avoid the sun (ES 1.09, CI 0.39 1.07, p < 0.001) and to use sunscreen (ES 0.71, CI 0.03 0.88, p < 0.05) after 1 month. Compared to the control group, there was no significant effect on sunscreen use and further psychosocial outcomes. The effectiveness of CLEVER may be underrated due to a high drop-out rate. Within three years, an enhanced free-of-charge program kit, including a media-based workshop and materials, had reached over 4000 preschools, i.e., 7.1% of all daycare centers in Germany. The results show that CLEVER can strengthen sun protection, offer high-quality information at low cost, and is easily disseminable.

The effect of 'I am Protecting my Child from the Sun' programme on parental sun protection behaviours: Randomized controlled trial

AIMS

This study aims to examine the effect of the 'I am Protecting my Child from the Sun' program based on the social cognitive theory, on parental use of sun protection products and sun avoidance behaviours.

DESIGN

Cluster randomized controlled trial.

METHODS

The study was conducted with three groups using a pre-test, post-test, and follow-up design. The study included 185 parents, of which 63 were in the education group, 62 were in the education + SMS group, and 60 were in the control group. The parents in the intervention group were engaged in the 'I am Protecting my Child from the Sun' program for a period of 6 weeks, while the education + SMS group, in addition to the program, also received. Primary outcomes include sunscreen use and sun avoidance behaviour and secondary outcomes were self-protection and protection of their children's behaviour. A repeated-measures ANOVA and marginal homogeneity were the main statistical tests.

RESULTS

The interventions made as part of the 'I am Protecting my Child from the Sun' program increased the following behavioural components of parents in the education group and the education + SMS group, compared with the control group: sun protection product use behaviours, sun avoidance behaviours, and behaviours related to protecting themselves and their children from the sun. There was an even higher increase in these behavioural components for those parents who also received short reminder text messages.

CONCLUSION

The 'I am Protecting my Child from the Sun' program and the receiving of short reminder messages had positive effects on the parents' behaviours related to protecting themselves and their children from the sun.

IMPACT

The 'I am Protecting my Child from the Sun' developed parents' sunscreen use self-efficacy, norms/attitudes about sunscreen use and sunscreen use expectancy behaviour, and reduced their impediments to sunscreen use behaviour. In addition, the program developed parents' sun avoidance self-efficacy, norms/attitudes about sun avoidance and sun avoidance expectancy behaviours, and reduced tanning expectancy behaviour. Receiving SMS messages following the training was effective in parental behaviours for use of sunscreen, sun avoidance, and protecting themselves and their children from the sun. Registration number: Study is registered at ClinicalTrials.gov NCT04251598.

Sunburn-related variables, secular trends of improved sun protection and short-term impact on sun attitude behavior in Italian primary schoolchildren: Analysis of the educational campaign "Il Sole Amico" ("The sun as a friend")

Sun protection early in life is an essential issue for primary prevention of skin cancers. The Il Sole per Amico was an educational campaign among 66 Italian primary schools. A total of 12,188 questionnaires were completed at baseline. Overall, 9.4% children reported >1 sunburn during the last year and 44.7% parents a use of sunlamps. Independent factors associated with sunburns were: age, lower level of parents' education, light eye and skin color, freckles, nevi on arms, intense sun exposure during the last year, sporadic use of sunscreens, and parental use of sunlamps. A total of 7280 (59.7%) questionnaires were completed at the end of the educational intervention. No significant difference was documented about behavior between the pre- and post-intervention periods. A significant reduction was instead found in both prevalence of recent sunburns and total number of sunburn episodes after comparison with the data obtained by identical questionnaire in the same geographic areas in the "Sole Si Sole No" project in 2001.

Shedding Light on the Shade: How Nurseries Protect Their Children from Ultraviolet Radiation

Minimizing exposure to ultraviolet radiation (UVR) is strongly recommended as the most important primary prevention measure regarding skin cancer. The responsibility for adequate sun protection of young children lies with their parents and external caregivers. Since a high proportion of 3- to 6-year-old children in Germany attend nurseries, the practice of sun protection in this setting was assessed. A survey was conducted in 246 nurseries in southern Germany during spring and summer of 2014 and 2015. Shade coverage in the outdoor area of the nursery was assessed by study team members and UVR protective behavior of staff was assessed by an interview with the directors. On average, 52% of the entire outdoor area and 65% of the children’s outdoor play area were covered by shade, with a significant difference between nurseries of different sizes, pointing to a better shade coverage in larger nurseries. The daily outdoor stay was not regularly scheduled before or after peak sun intensity hours around noon to avoid intense UVR exposure. General sun protection rules were present in the majority of the nurseries and addressed predominantly wearing sunhats and applying sunscreen. Our findings show that current sun protection recommendations for children are only partially met in nurseries and indicate a lower level of sun protection in small institutions. Especially, avoidance of excessive exposure to UVR around noon and the importance of shade provision over play structures needs to be emphasized in future information campaigns.

Sun-related knowledge and attitudes of primary and secondary schoolchildren in western Switzerland

Switzerland, particularly its western region, has the highest incidence of melanoma in Europe. Although the risk of melanoma increases with sun overexposure during childhood, sun-related knowledge and attitudes of Swiss children are scarcely documented. We report the first investigation of the knowledge of the danger of ultraviolet radiation, attitudes towards a suntan and parental influence of schoolchildren in western Switzerland. All fifth, eighth and eleventh graders (average ages of 9, 12 and 15, respectively) in the 18 primary (fifth grade, n=431) and secondary (eighth and eleventh grades, n=837) public schools of La Chaux-de-Fonds were surveyed during regular school classes. The response rate was 91% (1154/1268). Sun-related knowledge was high overall. Eight out of 10 children knew about the risk of skin cancer and recognized the most susceptible phototype. Knowledge increased significantly with age. Girls, older children, fair-skinned participants and those who preferred a tanned skin obtained the highest knowledge score. The main source of information on ultraviolet radiation and sun protection was their parents (76%), followed by the school (11%) and the media (9%). Multivariate logistic regression analyses identified higher sun-related knowledge, lower familial socioprofessional status and skin phototypes III-IV to be associated with a tan-seeking attitude. Parental sensitization (56%) and encouragement (61%) towards sun protection were more common among fair-skinned children and those of higher familial socioprofessional status. The high awareness of the risk of skin cancer among Swiss schoolchildren does not translate into appropriate attitudes. Community-wide intervention programmes involving parents, teachers, peers and primary care clinicians could be considered for Swiss prevention campaigns to improve children's sun behaviour and change their current pro-tan attitude.

St. Jude Cancer Education for Children Program: The Impact of a Teacher-Led Intervention on Student Knowledge Gains

In 2006, St. Jude Children's Research Hospital (Memphis, Tennessee) began developing a school-based outreach program known as the St. Jude Cancer Education for Children Program (SJCECP). The aim of this program is to teach Memphis-area children about cells, cancer, and healthy habits that can prevent the development of cancer in adulthood. Initial plans for delivery of the program was for St. Jude staff to present the program at local schools. This plan for disseminating instruction was not feasible due to the limited availability of St. Jude staff. As a next step, during the 2012-2014 academic years, we conducted a study entitled SJCECP2, utilizing the SJCECP curriculum, with the objective of evaluating the impact of the educational intervention on knowledge acquisition and retention among fourth-grade students participating in a modified, teacher-led version of the program. Eighteen teachers and 426 students from 10 local schools in the greater Memphis area participated in the program evaluation. This study used a single-group, pre-test/post-test design to determine the impact of the SJCECP intervention on changes in knowledge scores among fourth-grade students. Testing was on cells, cancer, and healthy living. The mean scores increased from 6.45 to 8.12, 5.99 to 7.65, and 5.92 to 7.96 on cell, cancer, and health behaviors units, respectively (all p values <.001). Preliminary evidence suggests that the SJCECP2 intervention is a useful tool for teachers to improve student knowledge of knowledge of cells, cancer, and healthy living concepts at the fourth-grade level.

CONSENSUS REPORT: Recognizing non-melanoma skin cancer, including actinic keratosis, as an occupational disease - A Call to Action

1. Non-melanoma skin cancer (NMSC) is by far the most common cancer diagnosed in westernized countries, and one of the few almost preventable cancers if detected and treated early as up to 90% of NMSC may be attributed to excessive exposure to ultraviolet radiation. 2. The incidence of NMSC is increasing: 2-3 million people are diagnosed worldwide annually, with an average yearly increase of 3-8% among white populations in Australia, Europe, the US and Canada over the last 30 years. 3. The link between solar ultraviolet (UV) radiation and certain forms of NMSC is clearly recognized. It is estimated that outdoor workers are exposed to an UV radiation dose 2-3 times higher than indoor workers, and there is a growing body of research linking UV radiation exposure in outdoor workers to NMSC: I. Occupationally UV-exposed workers are at least at a 43% higher risk of basal cell carcinoma (BCC) and almost doubled risk of squamous cell carcinoma (SCC) compared to the average population, with risk increasing with decreasing latitude. II. The risk for BCC, SCC and actinic keratosis (AK) among workers who have worked outdoors for more than 5 years is 3-fold higher than the risk among those with no years of working outdoors. 4. Primary prevention, early detection, treatment and regular follow-up of skin cancer (NMSC and melanoma) are shown to be beneficial from a health economic perspective. 5. Action is needed at international, European and national level to legislate for recognizing AK and NMSC as an occupational disease, which has the potential to improve access to compensation and drive preventative activities. 6. This report is a Call to Action for: I. The engagement of key stakeholders, including supranational institutions, national governments, trade organizations, employers, workers and patient organizations to drive change in prevention and protection of at-risk groups. II. Employers should be obliged to prevent outdoor worker's UV exposure from exceeding limit values, and to implement occupational skin cancer screening programmes among the at-risk workforce. III. Educational programmes for the outdoor workforce are needed to improve health literacy and drive behavioural change. IV. Nationally, steps to improve notifications and surveillance of skin cancers through both occupational services and public health programmes are required. V. Future research activities should focus on the precise definition of at-risk groups among outdoor workers through increased data gathering, including UV-dosimetry, and evaluation.

Multi-Level Models of Internalizing Disorders and Translational Developmental Science: Seeking Etiological Insights that can Inform Early Intervention Strategies

This commentary discusses the articles in this special section with an emphasis on the specific utility of multivariate, multi-level models in developmental psychopathology for ultimately contributing to both etiologic insights and translational advances. These issues are considered not only in terms of the specific papers, but also within a larger set of questions regarding the opportunities (and challenges) currently facing the field. We describe why we believe this an exciting time for integrative team-science approaches to tackle these challenges--a time that holds great promise for rapid advances in integrative developmental science that includes a biological level of mechanistic understanding. In order to facilitate this, we outline a range of approaches within both translational neuroscience and translational developmental science that can be used as frameworks for understanding how such research can provide etiologic insights regarding real-world targets at the level of social, behavioral, and affective processes that can be modified during key developmental windows of opportunity. We conclude that a "construct validity" framework, where biological data form a critical, but not privileged, component of key etiological mechanisms, combined with a developmental perspective on key period of sensitivity to intervention effects, is most likely to provide significant translational outcomes.

The case for targeting community pharmacy-led health improvement: Findings from a skin cancer campaign in Wales

Objectives

The aims of the study were: to examine the association between high risk behaviour and deprivation and contribute evidence to the case for or against targeting cancer prevention campaigns at specific risky behaviour in areas of high deprivation.

Methods

This study has an ecological design and involved retrospective analysis of data derived from 5739 sun-safety quizzes completed by pharmacy users at 714 community pharmacies in Wales during May 2014.

Results

Levels of participation in the campaign and high risk sun-safety behaviours were higher in more deprived areas. Respondents from deprived areas had significantly lower sun-safety knowledge. 3802 (66.2%) respondents reported ‘excellent’ or ‘good’ knowledge of behaviours which promote sun-safety but this did not necessarily translate into how individuals behaved. 3787 (66.1%) respondents considered community pharmacies an acceptable location for the campaign and for discussing the signs and symptoms of skin cancer.

Key Findings

Results show association between high risk behaviour and geographically defined deprivation adding to the case for targeting cancer prevention campaigns at specific behaviours and geographies.

Conclusions

Community pharmacies appear to be acceptable locations from which to deliver health improvement campaigns in terms of participant recruitment, ease of delivery, and pharmacy user feedback.

Malondialdehyde-derived epitopes in human skin result from acute exposure to solar UV and occur in nonmelanoma skin cancer tissue

Cutaneous exposure to solar ultraviolet radiation (UVR) is a causative factor in photoaging and photocarcinogenesis. In human skin, oxidative stress is widely considered a key mechanism underlying the detrimental effects of acute and chronic UVR exposure. The lipid peroxidation product malondialdehyde (MDA) accumulates in tissue under conditions of increased oxidative stress, and the occurrence of MDA-derived protein epitopes, including dihydropyridine-lysine (DHP), has recently been substantiated in human skin. Here we demonstrate for the first time that acute exposure to sub-apoptogenic doses of solar simulated UV light (SSL) causes the formation of free MDA and protein-bound MDA-derived epitopes in cultured human HaCaT keratinocytes and healthy human skin. Immunohistochemical staining revealed that acute exposure to SSL is sufficient to cause an almost twenty-fold increase in general MDA- and specific DHP-epitope content in human skin. When compared to dose-matched solar simulated UVA, complete SSL was more efficient generating both free MDA and MDA-derived epitopes. Subsequent tissue microarray (TMA) analysis revealed the prevalence of MDA- and DHP-epitopes in nonmelanoma skin cancer (NMSC). In squamous cell carcinoma tissue, both MDA- and DHP-epitopes were increased more than threefold as compared to adjacent normal tissue. Taken together, these date demonstrate the occurrence of MDA-derived epitopes in both solar UVR-exposed healthy human skin and NMSC TMA tissue; however, the potential utility of these epitopes as novel biomarkers of cutaneous photodamage and a functional role in the process of skin photocarcinogenesis remain to be explored.