UV-induced skin cancer at workplace and evidence-based prevention

Degree of Actinic Elastosis Is a Surrogate of Exposure to Chronic Ultraviolet Radiation and Correlates More Strongly with Cutaneous Squamous Cell Carcinoma than Basal Cell Carcinoma

(1) Background: Keratinocyte cancer (KC) is associated with exposure to ultraviolet (UV) radiation. However, data are controversial as to whether chronic UV exposure or high intermittent UV exposure are key drivers of carcinogenesis in cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC). Prolonged sun exposure of the skin causes photo-aging, which is associated with actinic elastosis, a condition characterized by the degeneration of elastin in the upper dermis, which is assessable via conventional histology. In this study, we aimed to compare the degree of actinic elastosis in different types of KC with regard to various patient characteristics. (2) Methods: We defined a semiquantitative score for the degree of actinic elastosis ranging from 0 = none to 3 = total loss of elastic fibers (basophilic degeneration). The extent was measured histometrically by two independent dermatohistopathologists in the immediate vicinity of 353 KC. The scores were merged and matched with tumor types (cSCC and BCC with subtypes), and clinical variables such as body site, sex and age. (3) Results: As expected, the degree of actinic elastosis correlated with age. However, it was significantly higher in cSCC compared to BCC irrespective of age, sex, body site and tumor subtypes. (4): Conclusions: Lifetime sun exposure may be estimated via routine histology using this scoring technique for actinic elastosis as a surrogate marker. cSCCs are more strongly associated with chronic UV exposure than BCCs, even in sun-exposed localizations such as the face.

Body site locations of basal cell carcinoma, squamous cell carcinoma and actinic keratosis in patients referred to the Waikato District Health Board teledermoscopy clinic

Introduction Basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and actinic keratosis (AK) are usually located on sun-exposed areas of the body. Aims Our main aims were to identify the common body site locations of BCC, SCC and AK in patients attending the Waikato District Health Board teledermoscopy clinic, also known as the Waikato Virtual Lesion Clinic, as well as to analyse whether the distribution of location changes with age and sex. Methods This is a retrospective study where the body site location of 3272 keratinocytic lesions was determined and analysed in 1864 patients attending the Waikato District Health Board teledermoscopy clinics between 2010 and 2021. Results All three types of lesion were most commonly located in the head and neck region (40.9% of BCCs, 38% of SCCs, 83.2% of AKs), followed by 26.8% on the trunk for BCC, 32.3% on the lower extremities for SCC, and 11.6% on the upper extremities for AK. Discussion Our findings of body site locations for keratinocytic lesions were consistent with other studies. Patients were commonly diagnosed with multiple keratinocytic lesions.

Genetic Factors Affect the Survival and Behaviors of Selected Bacteria during Antimicrobial Blue Light Treatment

Antimicrobial resistance is a global, mounting and dynamic issue that poses an immediate threat to human, animal, and environmental health. Among the alternative antimicrobial treatments proposed to reduce the external use of antibiotics is electromagnetic radiation, such as blue light. The prevailing mechanistic model is that blue light can be absorbed by endogenous porphyrins within the bacterial cell, inducing the production of reactive oxygen species, which subsequently inflict oxidative damages upon different cellular components. Nevertheless, it is unclear whether other mechanisms are involved, particularly those that can affect the efficacy of antimicrobial blue light treatments. In this review, we summarize evidence of inherent factors that may confer protection to a selected group of bacteria against blue light-induced oxidative damages or modulate the physiological characteristics of the treated bacteria, such as virulence and motility. These include descriptions of three major photoreceptors in bacteria, chemoreceptors, SOS-dependent DNA repair and non-SOS protective mechanisms. Future directions are also provided to assist with research efforts to increase the efficacy of antimicrobial blue light and to minimize the development of blue light-tolerant phenotypes.

Economic evaluation of interventions to reduce solar ultraviolet radiation (UVR) exposure among construction workers

Solar ultraviolet radiation is one of the most common occupational carcinogens in Canada and is responsible for approximately 5,556 non-melanoma skin cancers per year. A large part of these cases are preventable by reducing solar ultraviolet radiation exposure. In this study, investigators estimated the potential economic impacts of different solar ultraviolet radiation reduction interventions among construction workers, as they are one of the largest at-risk occupational groups. Investigators performed an economic evaluation from a societal perspective, by comparing incremental costs in relation to incremental benefits achieved by two interventions-use of personal protective equipment by all exposed individuals and use of shade structure wherever and whenever feasible. Interventions costs were estimated for 2020-2050, and benefits with a 10-year delay, i.e., for the period 2030-2060. Economic evaluation estimates were reported by intervention costs, total costs of non-melanoma skin cancers cases averted, incremental cost per avert case, return on investment, and the break-even point. Various sensitivity analyses were undertaken with key parameters. Our findings indicate that if the rising trend of incidence continues, cases will be double in 2060, whereas by using personal protective equipment or shade structure, with the best-case scenario of full ultraviolet radiation removal, would result in 6,034 and 2,945 cases averted over 30 years, respectively. This translates into a total of $38.0 and $20.5 million of averted costs (all monetary values represented in 2017 Canadian dollars). Under this scenario investigators expect that by 2060, for every dollar invested in personal protective equipment and shade structures, $0.49 and $0.35 will be returned, respectively. Findings also suggested that under a conservative scenario, prevention of non-melanoma skin cancer cases by personal protective equipment and shade structures resulted in $5,812 and $7,355 incremental costs, respectively, over the 30-year period. This study provides important insights for decision makers about the potential impacts of solar ultraviolet radiation reduction interventions in the construction sector and other sectors with substantial outdoor work. Our estimates also can raise awareness of the importance of solar ultraviolet radiation reduction interventions.

Antimicrobial Blue Light versus Pathogenic Bacteria: Mechanism, Application in the Food Industry, Hurdle Technologies and Potential Resistance

Blue light primarily exhibits antimicrobial activity through the activation of endogenous photosensitizers, which leads to the formation of reactive oxygen species that attack components of bacterial cells. Current data show that blue light is innocuous on the skin, but may inflict photo-damage to the eyes. Laboratory measurements indicate that antimicrobial blue light has minimal effects on the sensorial and nutritional properties of foods, although future research using human panels is required to ascertain these findings. Food properties also affect the efficacy of antimicrobial blue light, with attenuation or enhancement of the bactericidal activity observed in the presence of absorptive materials (for example, proteins on meats) or photosensitizers (for example, riboflavin in milk), respectively. Blue light can also be coupled with other treatments, such as polyphenols, essential oils and organic acids. While complete resistance to blue light has not been reported, isolated evidence suggests that bacterial tolerance to blue light may occur over time, especially through gene mutations, although at a slower rate than antibiotic resistance. Future studies can aim at characterizing the amount and type of intracellular photosensitizers across bacterial species and at assessing the oxygen-independent mechanism of blue light-for example, the inactivation of spoilage bacteria in vacuum-packed meats.

Design and baseline data of a randomized trial comparing two methods for scaling-up an occupational sun protection intervention

Background

Successful methods for scaling-up evidence-based programs are needed to prevent skin cancer among adults who work outdoors in the sun.

Methods

A randomized trial is being conducted comparing two methods of scaling-up the Sun Safe Workplaces (SSW) intervention. Departments of transportation (DOTs) from 21 U.S. states are participating and their 138 regional districts were randomized following baseline assessment. In districts assigned to the in-person method (n = 46), project staff meets personally with managers, conducts trainings for employees, and provides printed materials. In districts assigned to the digital method (n = 92), project staff conduct these same activities virtually, using conferencing technology, online training, and electronic materials. Delivery of SSW in both groups was tailored to managers' readiness to adopt occupational sun safety. Posttesting will assess manager's support for and use of SSW and employees' sun safety. An economic evaluation will explore whether the method that uses digital technology results in lower implementation of SSW but is more cost-effective relative to the in-person method.

Results

The state DOTs range in size from 997 to 18,415 employees. At baseline, 1113 managers (49.0%) completed the pretest (91.5% male, 91.1% white, 19.77 years on the job, 66.5% worked outdoors; and 24.4% had high-risk skin types). They were generally supportive of occupational sun safety. A minority reported that the employer had a written policy, half reported training, and two-thirds, messaging on sun protection.

Conclusions

Digital methods are available that may make scale-up of SSW cost-effective in a national distribution to nearly half of the state DOTs.

Trial registration: The ClinicalTrials.gov registration number is NCT03278340.

Non-Melanoma Skin Cancer in Outdoor Workers: A Study on Actinic Keratosis in Italian Navy Personnel

Occupational exposure to ultraviolet radiation is one of the main risk factors for non-melanoma skin cancer (NMSC) development. The most common variants of NMSC are basal cell carcinomas, squamous cell carcinomas, and actinic keratosis (AK). The latter is nowadays considered by most authors as an early squamous cell carcinoma rather than a precancerous lesion. Outdoor workers have a higher risk of developing NMSC because they spend most of the working day outside. The aim of this descriptive study was to assess the prevalence of skin lesions, especially AK, in a professional category of individuals exposed to ultraviolet (UV) radiation: the Italian Navy. From January to June 2016, a questionnaire and a total skin examination of 921 military personnel were administered by medical specialists (dermatologists) in seven different Italian Navy centres. AK was detected in 217 of 921 (23.5%) workers. Older age, outdoor occupation, longer working life, and fair skin seem to promote the development of AK. Of the 217 workers with AK, 187 (86.2%) had lesions in chronically sun-exposed skin areas. Italian Navy personnel have a high AK prevalence. Further studies are needed to investigate occupational hazards and their health effects among outdoor workers to promote protective behaviour and raise awareness of skin cancer.

Advances and controversies in studying sunscreen delivery and toxicity

This review critically evaluates the sunscreen delivery and toxicity field. We chose to focus on approved sunscreens in this review. Optimal sunscreen use prevents skin cancer and photoageing but there is an important knowledge gap in sunscreen/skin interactions. Sunscreen delivery is a key for efficacy, but studying sunscreen delivery is not straightforward. We review the strengths and weaknesses of in vitro, excised skin and clinical approaches. Understanding positive and negative sunscreen effects on skin homeostasis is also challenging. The results in this field, especially in vitro testing, are controversial and experimental design varies widely which further supports disparities between some findings. We hypothesize that bias towards showing sunscreen toxicity to increase impact could be problematic. We explore that perception through a detailed review of experimental design, especially in cell culture models. Our conclusion is that emerging, non- and minimally invasive technologies are enabling new approaches to volunteer studies that could significantly improve knowledge of sunscreen delivery and interactions.

Investigating partitioning of free versus macrocycle bound guest into a model POPC lipid bilayer

We report on the permeation of free and macrocycle-bound avobenzone across a POPC lipid bilayer through combined neutron reflectometry experiments and molecular dynamics simulations. Results indicate that the p-phosphonated calix[8]arene macrocycle limits the avobenzone penetration into the upper leaflet of the membrane. Hence, it could serve as a useful vehicle for safer formulations.

We report on the permeation of free and macrocycle-bound avobenzone across a POPC lipid bilayer through combined neutron reflectometry experiments and molecular dynamics simulations.

Outdoor work as a risk factor for high-grade cutaneous squamous cell carcinoma of the head and neck

INTRODUCTION

While it is clear that individuals with outdoor occupations are at a significantly greater risk of developing cutaneous squamous cell carcinoma (cSCC), no previous studies have investigated the potential association between the tumour grade and occupation in this patient population.

AIM

To assess occupation as a risk factor for the development of high-grade cSCC. Secondarily, to determine the association between the tumour grade and other clinical characteristics.

MATERIAL AND METHODS

Retrospective analysis of 256 patients treated for head and neck cSCC at our institution in 2007-2016. The following patient characteristics and variables were assessed: age; sex; tumour location and grade; profession; and education level. A univariate analysis was performed to assess the association between each study variable and grade 3 tumour differentiation.

RESULTS

The following variables were significantly associated (p < 0.05) with grade 3 (G3) cSCC tumours: outdoor work vs. indoor work; primary school vs. high school education; and age. Additionally, patients with low-grade (G1) tumours were significantly younger (mean age: 72) than patients with high-grade (G3) tumours (mean age: 79) (p = 0.046).

CONCLUSIONS

To our knowledge, this is the first study to assess the variables associated with the tumour grade among outdoor workers. These findings suggest that outdoor workers who develop cSCC are at a greater risk of developing more aggressive cancers. These findings provide additional support for classifying cSCC as an occupational disease. Early education about the dangers of sun exposure during the first years of school is essential to minimize the risks of developing high-grade skin cancer.

Skin cancer in the military: A systematic review of melanoma and nonmelanoma skin cancer incidence, prevention, and screening among active duty and veteran personnel

BACKGROUND

Occupational sun exposure is a well-studied risk factor for skin cancer development, but more work is needed to assess melanoma and nonmelanoma skin cancer risk among US military personnel to improve education and screening efforts in this population.

OBJECTIVE

To conduct an extensive review of skin cancer risks for US military personnel to inform preventive education, diagnosis, and treatment efforts to better protect these individuals from future skin cancer development.

METHODS

A systematic review of published studies on the subject of melanoma and nonmelanoma skin cancer in military personnel was conducted.

RESULTS

A total of 9 studies describing skin cancer incidence in the US military were identified, with 4 studies specific to melanoma. The study findings reveal an increased risk for melanoma associated with service in the military or prisoner of war status. Service in tropical environments was associated with an increased incidence of both melanoma and nonmelanoma skin cancer among World War II soldiers. Two studies found that increased melanoma risk was also branch dependent, with the highest rates among the United States Air Force. Several of the reviewed studies implicated increased sun exposure during military service and lack of sufficient sun protection as the causes of higher rates of skin cancer among US military and veteran populations as compared with among the nonmilitary population in the United States.

LIMITATIONS

The reviewed articles have variable results; a prospective randomized controlled trial would be helpful to develop interventions that mitigate skin cancer risk in the US military.

CONCLUSION

This review identifies an abundance of evidence for an increased risk for skin cancer development among US active duty and veteran populations.

The epidemic spreading of basal cell carcinoma: incidence trend, demographic features, characteristics and risk factors in a retrospective study of 8557 lesions in Bologna. A 25-year analysis in a Dermatology referral center

BACKGROUND

The aim of this study was to retrospectively analyze all the cases of BCC histologically diagnosed in the Cutaneous Tumor Center of Dermatology of Bologna University, in a period between 1990 and 2014.

METHODS

All the consecutive histopathologically diagnosed BCCs at the Dermatology of the Bologna University from 1990 to 2014 were retrospectively reviewed. We evaluated the absolute number of basal cell carcinoma (BCCs), the demographic features of patients and the characteristics of BCCs with statistically significant correlations.

RESULTS

During the investigated 25 years, 8557 BCCs were collected in 7297 patients. We observed that the incidence of this cancer, after stabilizing around a plateau of 400 cases/year in 2005, progressively increased onwards reaching a maximum of cases (821) in 2014 (+105.25%), with an 8.32% mean increase per year in those last 9 years. Moreover, we found a significant correlation (P<0.01%) between gender and the onset of BCC, between the anatomic location and the occurrence of the tumor, between the onset of recurrent or new BCCs and sun exposure.

CONCLUSIONS

The present study collects the largest series in the Italian literature focused on demographic features and characteristics of BCC, highlights its higher increasing incidence in Bologna and the need to improve preventive strategies to stem the epidemic diagnosis of BCC.

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.

Implementation of Ultraviolet Radiation Safety Measures for Outdoor Workers

Ultraviolet radiation (UVR) poses a major risk for outdoor workers, putting them at greater risk for skin cancer. In the general population, the incidence of both melanoma and nonmelanoma skin cancers is increasing. It is estimated that 90% of skin cancers in Canada are directly attributable to UVR exposure, making this cancer largely preventable with the appropriate precautions. A scoping review was conducted on the barriers and facilitators to UVR safety in outdoor workers to elucidate why these precautions are not in use currently. We discuss these results according to the Hierarchy of Controls as a means to outline effective and feasible prevention strategies for outdoor workers. In doing so, this review may be used to inform the design of future workplace interventions for UVR safety in outdoor workers to decrease the risk of skin cancer in this vulnerable population.

Is UV an etiological factor of acral melanoma?

Ultraviolet (UV) radiation is a major environmental risk factor for melanoma, particularly among Caucasians. However, studies have generated conflicting results on the role of UV exposure in the development of acral melanoma, the most prevalent subtype of melanoma in non-Caucasians. In this review, we analyzed studies that have examined the relationship between acral melanoma and UV and show that acral melanoma has specific epidemiological and genetic characteristics, with a lower frequency or absence of UV-induced features. Therefore, we postulate that UV is probably not involved in the etiology of acral melanoma. However, further epidemiological and laboratory studies are required to fully address this controversial issue, which may lead to a better understanding of the pathogenesis and prevention of acral melanoma.

Adoption of sun safe workplace practices by local governments

CONTEXT

Outdoor workers are especially susceptible to skin cancer--the most common, but also one of the most preventable, forms of cancer. Colorado, the location of the study, has the second highest rate of skin cancer deaths in the nation.

OBJECTIVE

Local government managers in Colorado-in municipalities, counties, and special districts-were surveyed to ascertain the extent to which they engage in formal (written) and informal practices to protect their outdoor workers against excessive exposure to sun.

DESIGN

The survey consisted of 51 questions assessing awareness of formal or informal practices for sun protection of outdoor workers. An index of practices--the study's dependent variable--was created that was composed or practices such as providing employees free or reduced-cost sunscreen, wide-brimmed hats, sunglasses, long-sleeved work shirts, long work pants, and temporary or permanent outdoor shade shelters. Proscriptive policies, such as restricting the use of broad brimmed hats, were subtracted from the index. Surveys were completed by 825 administrators representing 98 jurisdictions. Responses from administrators in the same jurisdiction were averaged.

RESULTS

More than 40% of responding jurisdictions indicated that they engaged in informal sun safety practices. Tests conducted to determine what variables might account for the adoption of these sun protection practices found that the degree to which a community could be regarded as cosmopolite and as having an individualistic political culture were significant predictors. Type of government was also significant. Although, higher community income was a significant predictor, neither local government budget nor size was significant.

CONCLUSIONS

The adoption of sun safe practices bears low costs with potentially high returns. Findings from this study suggest that awareness campaigns might most effectively target cosmopolite communities, but that the greatest impact might be achieved by targeting localite communities. Government size and budget do not appear to be constraints in the adoption of sun safe practices.

Sun safety knowledge and practice in UK postal delivery workers

BACKGROUND

Postal delivery workers spend a large proportion of their work time outdoors, placing them at increased risk of skin cancer. To date, no studies have examined occupational sun safety knowledge and practice within this group in the UK.

AIMS

To describe the occupational sun safety knowledge and practice of UK postal delivery workers and to investigate the association of demographic, personal and occupational factors with knowledge and practice in order to identify potential strategies for improving sun safety in this occupational group.

METHODS

Postal delivery workers completed a questionnaire that collected data on occupational sun safety knowledge and practice in addition to demographic, personal and workplace characteristics. One-way analysis of variances were applied to assess differences in knowledge and practice by these characteristics.

RESULTS

A total of 1153 postal delivery workers completed the questionnaire, a 60% response rate. Thirty-three per cent reported receiving sun safety training within the previous 12 months. The majority of respondents reported correct knowledge on three of the six domains and good practice on four of the six behavioural domains. However, only one-fifth of respondents reported wearing sunglasses and ensuring a plentiful intake of water. Knowledge and practice differed significantly according to demographic, personal and workplace characteristics.

CONCLUSIONS

There is a need to raise the profile of occupational skin cancer in this occupational group and to increase the priority given to occupational sun safety policies alongside targeted and tailored interventions, the effect of which can be evaluated.

Factors Associated With Occupational Sun-Protection Policies in Local Government Organizations in Colorado

IMPORTANCE

Skin cancer prevention remains a national priority. Reducing chronic UV radiation exposure for outdoor workers through sun-safety practices is an important step to help reduce the incidence of skin cancer.

OBJECTIVE

To determine the presence of occupational sun-safety policies at local government organizations in a single state.

DESIGN, SETTING, AND PARTICIPANTS

Of 571 potentially eligible local government organizations of Colorado cities, counties, and special tax districts, we enrolled 98 in a randomized pretest-posttest controlled experiment starting August 15, 2010, that evaluated an intervention to promote the adoption of sun-safety policies. We used a policy-coding protocol to evaluate personal sun-protection practices, environmental and administrative controls, and policy directives for sun safety starting February 10, 2011. We report the baseline assessment of the occupational sun-protection policies of these organizations.

MAIN OUTCOMES AND MEASURES

The presence of an occupational sun-safety policy.

RESULTS

Overall, 85 local government organizations (87%) had policies that required personal sun-protection practices, including the use of eyewear, hats, and protective clothing. However, of the 98 responding organizations, only 8 hat policies (8%), 10 eyewear policies (10%), and 7 clothing policies (7%) mentioned sun protection as the intent of the policy. Only cosmopoliteness, operationalized as proximity to an urban area, was associated with the presence of a sun-safety policy (odds ratio, 0.99 [95% CI, 0.98-1.00]; P = .02).

CONCLUSIONS AND RELEVANCE

Outdoor workers are at increased risk for skin cancer because of long-term exposure to solar UV radiation. Although organizational policies have the potential to increase sun protection in occupational settings, occupational sun-safety policies were uncommon among local governments. Opportunities exist for dermatologists and other physicians to influence occupational sun-safety practices and policies, which are consistent with other safety procedures and could easily be integrated into existing workplace practices.

Sun Safety at Work Canada: a multiple case-study protocol to develop sun safety and heat protection programs and policies for outdoor workers

BACKGROUND

CAREX Canada has identified solar ultraviolet radiation (UV) as the second most prominent carcinogenic exposure in Canada, and over 75 % of Canadian outdoor workers fall within the highest exposure category. Heat stress also presents an important public health issue, particularly for outdoor workers. The most serious form of heat stress is heat stroke, which can cause irreversible damage to the heart, lungs, kidneys, and liver. Although the need for sun and heat protection has been identified, there is no Canada-wide heat and sun safety program for outdoor workers. Further, no prevention programs have addressed both skin cancer prevention and heat stress in an integrated approach. The aim of this partnered study is to evaluate whether a multi-implementation, multi-evaluation approach can help develop sustainable workplace-specific programs, policies, and procedures to increase the use of UV safety and heat protection.

METHODS/DESIGN

This 2-year study is a theory-driven, multi-site, non-randomized study design with a cross-case analysis of 13 workplaces across four provinces in Canada. The first phase of the study includes the development of workplace-specific programs with the support of the intensive engagement of knowledge brokers. There will be a three-points-in-time evaluation with process and impact components involving the occupational health and safety (OHS) director, management, and workers with the goal of measuring changes in workplace policies, procedures, and practices. It will use mixed methods involving semi-structured key informant interviews, focus groups, surveys, site observations, and UV dosimetry assessment. Using the findings from phase I, in phase 2, a web-based, interactive, intervention planning tool for workplaces will be developed, as will the intensive engagement of intermediaries such as industry decision-makers to link to policymakers about the importance of heat and sun safety for outdoor workers.

DISCUSSION

Solar UV and heat are both health and safety hazards. Using an occupational health and safety risk assessment and control framework, Sun Safety at Work Canada will support workplaces to assess their exposure risks, implement control strategies that build on their existing programs, and embed the controls into their existing occupational health and safety system.

Brazilian consensus on photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of non-melanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection.

Analysis of the B-RafV600E mutation in cutaneous melanoma patients with occupational sun exposure

Sun-exposure is one of the risk factors associated with the development of a cutaneous neoplasm. In melanoma, the Ras-Raf-MEK-ERK (MAPK) signaling pathway is constitutively activated through multiple mechanisms, including B-RAF mutation. It has been hypothesized that B-RAF mutations in melanocytic lesions arise from DNA damage induced by ultraviolet (UV) radiation. However, it is still discussed if B-RAF mutations are associated with melanoma patients exposed to the sun. Therefore, in the present study, the known B-RAF^V600E mutation was analysed in melanoma samples from 30 indoor and 38 outdoor workers. B-RAF^V600E mutation was detected in 52 and 73% of outdoor workers and indoor workers, respectively. Of note, this mutation was identified in 12 of 14 (85%) melanoma of the trunk diagnosed in indoor workers and in 9 of 19 (47%) samples from outdoor workers (p=0.03). By analyzing melanomas of other body sites, no statistical difference in the frequency of B-RAF^V600E mutation was identified between the groups of workers. It appears that the mutation detected among indoor workers may be associated with a recreational or intermittent exposure to the sun, as usually the trunk is a sun-protected body site. Overall, these data indicate that the B-RAF^V600E mutation detected in melanoma is not associated with a chronic exposure to the sun. Mutations detected in other genes may also contribute to melanoma development in the subset of patients exposed to UV radiation.

Non-melanoma skin cancer: occupational risk from UV light and arsenic exposure

Non-melanoma skin cancer (NMSC) has a significant impact on public health and health care costs as a result of high morbidity and disfigurement due to the destruction of surrounding tissues. Although the mortality rates of these tumors are low, the high incidence rates determine a considerable number of deaths. NMSC is the most common type of skin cancer, representing about 1/3 of all malignancies diagnosed worldwide each year. The most common NMSC are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Studies on humans and experimental animals indicate that ultraviolet (UV) light and arsenic play important roles in the development of these skin malignancies. Several epidemiological studies have investigated the risk of developing NMSC and the potential link between exposure to sunlight and arsenic in the agricultural and industrial occupational settings. To date, the published literature suggests that there is no apparent skin cancer risk as regards workplace exposure to artificial UV light or arsenic. Concerning UV light from sun exposure at the workplace, most published studies indicated an elevated risk for SCC, but are less conclusive for BCC. Many of these studies are limited by the methodology used in the evaluation of occupational exposure and the lack of adjustment for major confounders. Therefore, further epidemiological studies are required to focus on exposure assessment at the individual level as well as potential interactions with other occupational and non-occupational exposures and individual susceptibility. In doing so, we can better quantify the true risk of skin cancer in exposed workers and inform effective public health prevention programs.

Expression of GLTSCR2/Pict-1 in squamous cell carcinomas of the skin

The most important cause of cutaneous squamous cell carcinomas (SCC) is DNA damage induced by exposure to solar UV irradiation. DNA damage induced by UV irradiation is sensed by early DNA damage response (DDR) proteins. Recently, GLTSCR2 has been suggested to play a role in UV light-induced DDR. To explore the role of GLTSCR2 in the development of cutaneous SCC, we investigated the molecular mechanism underlying GLTSCR2 inactivation in response to UV irradiation. We analyzed cutaneous SCC (n=42), basal cell carcinomas (BCC; n=26), and normal skin tissue samples (n=36) and compared GLTSCR2 expression between tumor and normal tissues, using immunohistochemistry. Next, to investigate the effects of UV irradiation on GLTSCR2, we performed immunocytochemistry, RT-PCR, immunoblotting, half-life assay for GLTSCR2, and comet assay after UV irradiation in primary keratinocytes. GLTSCR2 expression in SCC was significantly lower than that of normal skin tissue (p<0.05), but not different between BCC and normal skin. In cultured primary keratinocytes, GLTSCR2 expression was decreased and translocated after UV irradiation. UV irradiation accelerated degradation of GLTSCR2 through proteasomal pathway. Knockdown of GLTSCR2 resulted in marked decrease in γH2AX foci after UV exposure. Furthermore, comet assay showed that DNA damage after UV exposure persists longer in GLTSCR2 knocked-down cells. Our data show that GLTSCR2 is downregulated in SCC of the skin and that UV light exposure decreases the stability of GLTSCR2 and sensitizes keratinocytes to DNA damage. Therefore, our data suggest that GLTSCR2 might be involved in the development and/or progression of SCC of the skin.

Management of actinic keratosis

Actinic keratoses are common, often multiple, epidermal lesions found mainly on the sun-exposed skin of fair-skinned middle-aged and older people.(1) Over time, lesions may remain unchanged or may proliferate, regress, reappear or develop into squamous cell carcinoma (SCC).(2) Detectable (spot) lesions are often associated with alteration of the surrounding skin (field) where subclinical lesions might be present.(2) Interventions may target individual or multiple lesions or a whole field.(2) Here, we update our previous review(3) on the prevention and treatment of actinic keratoses, focusing on the licensed treatments most commonly used in the UK and recommended in UK guidelines.

Reduced mortality rates in a cohort of long-term underground iron-ore miners

BACKGROUND

Historically, working in iron-ore mines has been associated with an increased risk of lung cancer and silicosis. However, studies on other causes of mortality are inconsistent and in the case of cancer incidence, sparse. The aim of this study was to examine the association between iron-ore mining, mortality and cancer incidence.

METHODS

A 54-year cohort study on iron-ore miners from mines in northern Sweden was carried out comprising 13,000 workers. Standardized rate ratios were calculated comparing the disease frequency, mortality, and cancer incidence with that of the general population of northern Sweden. Poisson regression was used to evaluate the association between the durations of employment and underground work, and outcome.

RESULTS

Underground mining was associated with a significant decrease in adjusted mortality rate ratios for cerebrovascular and digestive system diseases, and stroke. For several outcomes, elevated standardized rate ratios were observed among blue-collar workers relative to the reference population. However, only the incidence of lung cancer increased with employment time underground (P < 0.001).

CONCLUSIONS

Long-term iron-ore mining underground was associated with lower rates regarding several health outcomes. This is possibly explained by factors related to actual job activities, environmental exposure, or the selection of healthier workers for long-term underground employment.

Occupational exposure to ultraviolet radiation and risk of non-melanoma skin cancer in a multinational European study

Background

Studies suggest that ambient sunlight plays an important role in the pathogenesis of non-melanoma skin cancers (NMSC). However, there is ongoing controversy regarding the relevance of occupational exposure to natural and artificial ultraviolet radiation (UV) radiation.

Objectives

We investigated potential associations between natural and artificial UV radiation exposure at work with NMSC in a case-control study conducted in Hungary, Romania, and Slovakia.

Methods

Occupational exposures were classified by expert assessment for 527 controls and 618 NMSC cases (515 basal cell carcinoma, BCC). Covariate information was collected via interview and multiple logistic regression models were used to assess associations between UV exposure and NMSC.

Results

Lifetime prevalence of occupational exposure in the participants was 13% for natural UV radiation and 7% for artificial UV radiation. Significant negative associations between occupational exposure to natural UV radiation and NMSC were detected for all who had ever been exposed (odds ratio (OR) 0.47, 95% confidence interval (CI) 0.27–0.80); similar results were detected using a semi-quantitative metric of cumulative exposure. The effects were modified by skin complexion, with significantly decreased risks of BCC among participants with light skin complexion. No associations were observed in relation to occupational artificial UV radiation exposure.

Conclusions

The protective effect of occupational exposure to natural UV radiation was unexpected, but limited to light-skinned people, suggesting adequate sun-protection behaviors. Further investigations focusing on variations in the individual genetic susceptibility and potential interactions with environmental and other relevant factors are planned.

The relationship between occupational sun exposure and non-melanoma skin cancer: clinical basics, epidemiology, occupational disease evaluation, and prevention

BACKGROUND

The cumulative effect of solar ultraviolet (UV) radiation is responsible for the worldwide increase in non-melanoma skin cancer, a category that includes squamous cell carcinoma and its precursors (the actinic keratoses) as well as basal-cell carcinoma. Non-melanoma skin cancer is the most common type of cancer in areas of the world with a light-skinned population. The occupational exposure to UV radiation is high in many outdoor occupations; recent studies suggest that persons working in such occupations are more likely to develop non-melanoma skin cancer.

METHODS

On the basis of a selective review of the literature, we present the current state of knowledge about occupational and non-occupational UV exposure and the findings of meta-analyses on the association of outdoor activity with non-melanoma skin cancer. We also give an overview of the current recommendations for prevention and for medicolegal assessment.

RESULTS

Recent meta-analyses have consistently documented a significantly higher risk of squamous cell carcinoma of the skin among persons who work outdoors (odds ratio [OR] 1.77, 95% confidence interval [CI] 1.40-2.22, p<0.001). There is also evidence for an elevated risk of basal-cell carcinoma (OR 1.43, 95% CI 1.23-1.66, p = 0.0001), but the effect is of lesser magnitude and the study findings are not as uniform.

CONCLUSION

The association of occupational exposure to solar UV radiation with squamous cell carcinoma, including actinic keratosis, has been conclusively demonstrated. It follows that, in Germany, suspected non-melanoma skin cancer in persons with high occupational exposure to UV radiation should be reported as an occupational disease under § 9, paragraph 2 of the Seventh Book of the German Social Code (Sozialgesetzbuch, SGB VII). Preventive measures are urgently needed for persons with high occupational exposure to UV radiation.

Prevalence of exposure to solar ultraviolet radiation (UVR) on the job in Canada

OBJECTIVE

Over one third of all newly diagnosed cancers in Canada in 2010 were skin cancer, despite the fact that skin cancer is largely preventable by limiting ultraviolet radiation (UVR) exposure. Outdoor workers are at risk of exposure to UVR, yet the prevalence of exposure in Canada is unknown. The objective of this study was to estimate the number of outdoor workers in Canada.

METHODS

Building on CAREX Canada methods, we used a combination of data in the original Finnish CAREX, an Australian skin cancer prevention workbook, career-selection websites, and published studies to flag jobs at high risk of exposure. We also created a category for moderate exposure, where workers were unlikely to spend their whole day outside. Adjustments were made for industry-driven exposure, and prevalence of exposure was assigned for all jobs. Prevalence data were linked to census data to derive the number of workers exposed to solar UVR.

RESULTS

Over 1.5 million Canadian workers are exposed to solar UV at work, and approximately 897,000 of these were flagged as "high exposed" (outdoors > or =75% of the workday). The largest occupational groups were farmers, construction labourers, and landscapers. Proportions of the workforce exposed ranged by province, with 6.9% of workers exposed in Ontario, and up to 17.3% in Prince Edward Island.

CONCLUSIONS

Information on solar UVR exposure prevalence is needed for primary skin cancer prevention with regard to targeting of high-risk groups, priority setting, and better risk assessment. This study showed that solar UVR exposure is occurring on a large scale in Canada.

The application of Levulan-based photodynamic therapy with imiquimod in the treatment of recurrent basal cell carcinoma

BACKGROUND

Common skin tumors like basal- and squamous-cell carcinoma present a serious problem in modern medicine. Exposure to ultraviolet solar radiation is the main cause of these lesions. Since application of Aldara and PDT separately is well documented, we decided to use both methods together. The aim of our study was to evaluate the effectiveness of local photodynamic therapy supplemented with topical application of Aldara in basal-cell carcinoma.

MATERIAL/METHODS

Thirty-four patients ages 50 to 68 years were enrolled to the trial and underwent PDT treatment. Each case of BCC was histopathologically confirmed. Ten patients were subjected to local Levulan-PDT and placebo (Eucerin as vehicle cream), and 24 patients were subjected to Levulan-PDT and imiquimod. Photodynamic diagnosis (PDD) was used to detect and visualize suspicious foci (including cancer lesions).

RESULTS

In the group of patients who were treated using Levulan-PDT and placebo, 6 patients (60%) were totally cured and 4 lesions (40%) significantly decreased in size. In the group of patients treated with Levulan-PDT and imiquimod, 18 lesions totally disappeared (75%), 6 lesions significantly diminished, and in 1 patient small foci of previously excised BCC developed again in scar tissue 10 month after the first control examination.

CONCLUSIONS

Cure was achieved without any scarring and with very good cosmetic effects. Although this is the preliminary report, the presented modification of PDT seems to be reasonable and promising in treating basal-cell carcinoma.

Roles of the immune system in skin cancer

Over the past several decades, there has been increasing interest in understanding the roles of the immune system in the development and progression of cancer. The importance of the immune system in human skin cancer has been long recognized based primarily upon the increased incidence of skin cancers in organ transplant recipients and mechanisms of ultraviolet (UV) radiation-mediated immunomodulation. In this review, we integrate multiple lines of evidence highlighting the roles of the immune system in skin cancer. First, we discuss the concepts of cancer immunosurveillance and immunoediting as they might relate to human skin cancers. We then describe the clinical and molecular mechanisms of skin cancer development and progression in the contexts of therapeutic immunosuppression in organ transplant recipients, viral oncogenesis, and UV radiation-induced immunomodulation with a primary focus on basal cell carcinoma and squamous cell carcinoma. The clinical evidence supporting expanding roles for immunotherapy is also described. Finally, we discuss recent research examining the functions of particular immune cell subsets in skin cancer and how they might contribute to both antitumour and protumour effects. A better understanding of the biological mechanisms of cancer immunosurveillance holds the promise of enabling better therapies.

Basal cell carcinoma: 10 years of experience

Introduction. Basal cell carcinoma (BCC) is a locally invasive malignant epidermal tumour. Incidence is increasing by 10% per year; incidence of metastases is minimal, but relapses are frequent (40%–50%). The complete excision of the BCC allows reduction of relapse. Materials and Methods. The study cohort consists of 1123 patients underwent surgery for basal cell carcinoma between 1999 and 2009. Patient and tumor characteristics recorded are: age; gender; localization (head and neck, trunk, and upper and lower extremities), tumor size, excisional margins adopted, and relapses. Results. The study considered a group of 1123 patients affected by basal cell carcinoma. Relapses occurred in 30 cases (2,67%), 27 out of 30 relapses occurred in noble areas, where peripheral margin was <3 mm. Incompletely excised basal cell carcinoma occurred in 21 patients (1,87%) and were treated with an additional excision. Discussion. Although guidelines indicate 3 mm peripheral margin of excision in BCC <2 cm, in our experience, a margin of less than 5 mm results in a high risk of incomplete excisions.