Risk and protective factors for sporadic basal cell carcinoma: results of a two-centre case-control study in southern Germany. Clinical actinic elastosis may be a protective factor

Occupational solar exposure and basal cell carcinoma. A review of the epidemiologic literature with meta-analysis focusing on particular methodological aspects

BACKGROUND

Numerous epidemiologic studies and a few systematic reviews have investigated the association between occupational solar exposure and basal cell carcinoma (BCC). However, previous reviews have several deficits with regard to included and excluded studies/risk estimates and the assessment of risk of selection bias (RoSB). Our aim was to review epidemiologic studies with a focus on these deficits and to use meta-(regression) analyses to summarize risk estimates.

METHODS

We systematically searched PubMed (including MEDLINE) and Embase for epidemiologic studies. Study evaluation considered four main aspects of risk of bias assessments, i.e. Selection of subjects (selection bias); Exposure variables; Outcome variables; Data analysis.

RESULTS

Of 56 identified references, 32 were used for meta-(regression) analyses. The overall pooled risk estimate for BCC comparing high/present vs. low/absent occupational solar exposure was 1.20 (95% CI 1.02-1.43); among studies without major deficits regarding data analysis, it was 1.10 (95% CI 0.91-1.33). Studies with low and high RoSB had pooled risk estimates of 0.83 (95% CI 0.73-0.93) and 1.95 (95% CI 1.42-2.67), respectively. The definitions of exposure and outcome variables were not correlated with study risk estimates. Studies with low RoSB in populations with the same latitude or lower than Germany had a pooled risk estimate of 1.01 (95% CI 0.88-1.15).

CONCLUSION

Due to the different associations between occupational solar exposure and BCC among studies with low and high RoSB, we reason that the current epidemiologic evidence base does not permit the conclusion that regular outdoor workers have an increased risk of BCC.

A meta-analysis of sunburn and basal cell carcinoma risk

Basal cell carcinoma (BCC) is the most common cancer in the United States. Sunburn is a modifiable risk factor for BCC. The objective of this project was to synthesize research on BCC and sunburn to quantify the impact and severity of sunburn at different life stages on BCC risk in the general population. A systematic literature search of four electronic databases was conducted and data were extracted by two independent reviewers using standardized forms. Data from 38 studies were pooled using both dichotomous and dose-response meta-analytic methods. BCC risk increased with ever experiencing a sunburn in childhood (OR=1.43, 95% CI: 1.19, 1.72) and with ever experiencing a sunburn in life (OR= 1.40, 95% CI: 1.02, 1.45). Every five sunburns experienced per decade in childhood increased BCC risk by 1.86 (95% CI: 1.73, 2.00) times. Every five sunburns experienced per decade in adulthood increased BCC risk by 2.12 (95% CI: 1.75, 2.57) times and every five sunburns per decade of life increased BCC risk by 1.91 (95% CI: 1.42, 2.58) times. The data on sunburn exposure and BCC show that an increase in number of sunburns at any age increased the risk of BCC. This may inform future prevention efforts.

Basal cell carcinoma: what new can be learned about the most common human cancer? A cross-sectional prospective study of 180 cases in a single centre

Introduction

Basal cell carcinoma (BCC) is the most common cancer in humans, but the reporting of patients with BCC is still not complete. There are a limited number of analyses in the literature on BCC epidemiology.

Aim

To study the epidemiological as well as clinical aspects of BCC by analysing a single centre’s experience in the Lower Silesia region of Poland.

Material and methods

We investigated 180 patients with BCC treated in the Unit of Dermatosurgery, Department of Dermatology, Venereology, and Allergology of Wroclaw Medical University between September 2017 and December 2019.

Results

The mean age of patients with BCC was 70.5 ±11.9 years. The most frequently diagnosed type of BCC was nodular type, at 72% of all patients. BCC occurred most commonly on the face and neck area, at 132 (73.3%), without a statistical difference between males and females. The vast majority of cancers were located on the nose. There was a personal history of skin cancer in 29% of our patients. In 127 (70.6%) subjects, the diameter of the BCC on the day of excision was less than 2 cm.

Conclusions

The clinical characteristics of our cohort of BCC patients has some similarities with that reported from central Poland and other European countries. However, we found an increase in the incidence of BCC among females.

Favre-Racouchot disease: protective effect of solar elastosis

Favre-Racouchot disease (FRD) is an occupational disorder characterized by solar elastosis with open and cystically dilated comedones that tend to appear on the periorbital and temporal face of elderly light-complexioned men. It is a benign condition caused by chronic excessive ultraviolet exposure, as well as ionizing radiation and/or smoking. However, malignant skin neoplasms are uncommonly observed arising in FRD, which suggests a protective role of some element of FRD against carcinogenesis. We explore elastosis as a possibly beneficial tissue response. The clinical manifestations, pathogenesis, and recommended treatment options of this disorder are reviewed.

Recommended Surgical Margins for Basal Cell Carcinoma: Is 3 mm Safe Enough?

OBJECTIVE

The primary aim of treatment of basal cell carcinoma (BCC) is the complete excision of the tumor. Reconstruction of the defect after surgical excision varies, depending on the location and size of the defect and the skin to be used in the reconstruction. In this study, investigators compared the rates of tumor positivity at the edges of BCC specimens excised with 3- or 5-mm surgical margins.

METHODS

Researchers analyzed data related to 113 patients with a preliminary diagnosis of BCC between August 2016 and June 2018. In total, 99 lesions from 91 patients not exceeding 2 cm in size excised with 3-mm (n = 53) or 5-mm (n = 46) surgical margins were included. Statistical analysis was performed using the χ test.

RESULTS

After histopathologic assessment, 3 of 53 lesions that were excised with 3-mm surgical margins had a positive surgical margin, whereas none of the 46 lesions excised with 5-mm margins indicated a positive tumor presence. However, there was no statistical difference between the groups.

CONCLUSIONS

A 3-mm surgical margin may be sufficient and safe for BCC excision.

The current burden of non-melanoma skin cancer attributable to ultraviolet radiation and related risk behaviours in Canada

PURPOSE

Ultraviolet radiation (UVR) is an established cause of non-melanoma skin cancer (NMSC)-basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). The aim of this study was to estimate the current burden of BCC and SCC associated with UVR and modifiable UVR behaviours (sunburn, sunbathing, and indoor tanning) in Canada in 2015.

METHODS

The current burden of BCC and SCC associated with UVR was estimated by comparing 2015 incidence rates with rates of less exposed body sites (trunk and lower limbs) after adjusting for estimated surface areas. The burden associated with modifiable UVR behaviours was estimated by using prevalence estimates among Caucasians from the Second National Sun Survey, and relative risks that are generalizable to Canadians from conducting meta-analyses of relevant studies.

RESULTS

We estimated that 80.5% of BCCs and 83.0% of SCCs were attributable to UVR. Adult sunburn was associated with relative risks of 1.85 (95% CI 1.15-3.00) for BCC and 1.41 (95% CI 0.91-2.18) for SCC, while adult sunbathing was associated with relative risks of 1.82 (95% CI 1.52-2.17) for BCC and 1.14 (95% CI 0.53-2.46) for SCC. We estimated that 18.6% of BCCs and 9.9% of SCCs were attributable to adult sunburn, while 28.1% of BCCs were attributable to adult sunbathing. We estimated that 46.2% of BCCs and 17.3% of SCCs were attributable to modifiable UVR behaviours combined.

CONCLUSION

Our results provide quantifiable estimates of the potentially avoidable burden of NMSCs among Canadians. These estimates can be used to motivate prevention efforts in Canada.

Basal cell carcinoma risk and solar UV exposure in occupationally relevant anatomic sites: do histological subtype, tumor localization and Fitzpatrick phototype play a role? A population-based case-control study

Background

A two-fold risk increase to develop basal cell carcinoma was seen in outdoor workers exposed to high solar UV radiation compared to controls. However, there is an ongoing discussion whether histopathological subtype, tumor localization and Fitzpatrick phototype may influence the risk estimates.

Objectives

To evaluate the influence of histological subtype, tumor localization and Fitzpatrick phototype on the risk to develop basal cell carcinoma in highly UV-exposed cases and controls compared to those with moderate or low solar UV exposure.

Methods

Six hundred forty-three participants suffering from incident basal cell carcinoma in commonly sun-exposed anatomic sites (capillitium, face, lip, neck, dorsum of the hands, forearms outside, décolleté) of a population-based, case-control, multicenter study performed from 2013 to 2015 in Germany were matched to controls without skin cancer. Multivariate logistic regression analysis was conducted stratified for histological subtype, phototype 1/2 and 3/4. Dose-response curves adjusted for age, age², sex, phototype and non-occupational UV exposure were calculated.

Results

Participants with high versus no (OR 2.08; 95% CI 1.24–3.50; p = 0.006) or versus moderate (OR 2.05; 95% CI 1.15–3.65; p = 0.015) occupational UV exposure showed a more than two-fold significantly increased risk to develop BCC in commonly UV-exposed body sites. Multivariate regression analysis did not show an influence of phototype or histological subtype on risk estimates. The restriction of the analysis to BCC cases in commonly sun-exposed body sites did not influence the risk estimates. The occupational UV dosage leading to a 2-fold increased basal cell carcinoma risk was 6126 standard erythema doses.

Conclusion

The risk to develop basal cell carcinoma in highly occupationally UV-exposed skin was doubled consistently, independent of histological subtype, tumor localization and Fitzpatrick phototype.

Global evidence on occupational sun exposure and keratinocyte cancers: a systematic review

Individual studies have suggested that the association between occupational exposure to solar ultraviolet radiation (UVR) and the development of keratinocyte cancers (KCs) may only be valid in populations of European ancestry living in certain geographical regions. Comparative global data are scarce and so this review aimed to summarize current evidence on the association between occupational exposure to solar UVR and the development of KCs, with a specific focus on geographical location and skin colour. Ovid MEDLINE, PubMed, Embase and Web of Science were searched for potentially relevant records. Extracted data were summarized by study, country and region. We included one prospective cohort study and 18 case-control studies (n = 15 233) from 12 countries in regions where the majority of the population is white skinned (Americas, Europe and Oceania). Eighteen of the 19 studies reported effect estimates suggesting an increased risk of basal cell carcinoma (BCC) and/or squamous cell carcinoma (SCC) among outdoor workers. Only 11 studies found a significantly increased risk and many had imprecise estimates. There was a significantly increased risk of BCC and SCC in individual studies in North America, Latin America and the Caribbean, Western Europe and Southern Europe, but not across regions or countries. Overall, 95% of studies reported higher risks among outdoor workers, although the increases in risk were statistically significant in just over half of the studies. Well-designed and sufficiently powered occupational case-control and cohort studies with adequate adjustment for confounding factors and other risk factors are required to provide more accurate risk estimates for occupational KC.

Photoaging and actinic keratosis in Danish outdoor and indoor workers

BACKGROUND

The risk of photoaging and actinic keratosis caused by work related solar ultraviolet radiation exposure has not previously been investigated in Nordic countries. The objectives of this study were to describe the occurrence of photoaging, actinic keratosis, and keratinocyte cancer in a population of Danish outdoor and indoor workers, and investigate the association between these clinical findings and semi-objective measures of work related solar ultraviolet radiation exposure in the same population.

METHODS

A clinical cross-sectional study of the occurrence of facial wrinkles, actinic keratosis, keratinocyte cancer, and melanocytic nevi in a population of Danish outdoor and indoor workers and associations with semi-objective measures of work related solar ultraviolet radiation exposure based on a combination of dosimetry and self-report.

RESULTS

Work related solar ultraviolet radiation exposure was significantly positively associated with occurrence of facial wrinkles (α = 0.05). Actinic keratosis was associated to status as outdoor worker (OR = 4.272, CI [1.045-17.471]) and age (P < 0.001, CI [1.077-1.262]) and twice as common in outdoor workers (10.3% CI [0.05, 0.15]) compared to indoor workers (5.1% CI [0.00, 0.10]). Only two cases of keratinocyte cancer were diagnosed (<1%). Older age was negatively associated with occurrence of melanocytic nevi.

CONCLUSION

Outdoor work in Denmark is associated with increased occurrence of facial wrinkles and actinic keratosis from solar ultraviolet radiation exposure, thus justifying sun safety at Danish workplaces from a clinical perspective.

Basal cell carcinoma: Epidemiology; pathophysiology; clinical and histological subtypes; and disease associations

As the most common human cancer worldwide and continuing to increase in incidence, basal cell carcinoma is associated with significant morbidity and cost. Continued advances in research have refined both our insight and approach to this seemingly ubiquitous disease. This 2-part continuing medical education article will provide a comprehensive and contemporary review of basal cell carcinoma. The first article in this series describes our current understanding of this disease regarding epidemiology, cost, clinical and histopathologic presentations, carcinogenesis, natural history, and disease associations.

Different outdoor professions have different risks - a cross-sectional study comparing non-melanoma skin cancer risk among farmers, gardeners and mountain guides

BACKGROUND

One of the main risk factors for non-melanoma skin cancer (NMSC), the most common cancer worldwide, is solar ultraviolet radiation (UVR). This has led to the recognition of NMSC as occupational disease for outdoor workers in several countries. However, outdoor professions are a very heterogeneous group with diverse daily activities and associated UVR exposure.

OBJECTIVE

To compare the prevalence of NMSC and associated risk behaviour in different outdoor professions.

METHODS

Cross-sectional study among outdoor workers (farmers, gardeners, mountain guides) and indoor workers (office employees) as control group using a paper-based questionnaire on UVR exposure and protective behaviour followed by a skin examination by a dermatologist.

RESULTS

A total of 563 participants (46.9% women, 46.9 ± 13.8 years) consisting of 348 outdoor workers (38.8% farmer, 35.3% gardener, 25.9% mountain guides) and 215 indoor workers were included in the study between March and September 2017. NMSC incl. actinic keratosis was diagnosed in 33.3% of mountain guides, 27.4% of farmers, 19.5% of gardeners and in 5.6% of indoor workers. Significant differences were seen between the outdoor professions with mountain guides at highest risk compared to farmers (OR = 2.6, 95% CI = 1.2-5.7). Substantial differences between the professions were also seen in skin cancer screening attendance rates (indoor worker 61.4%, mountain guides 57.8%, farmers 31.9%, gardeners 27.6%), daily UVR exposure during work and protective behaviour such as sunscreen use during work.

CONCLUSION

Different outdoor professions have significant different risks for NMSC and show different risk behaviour. Tailoring prevention efforts to different professions based on their individual needs could be the key to lower the global burden of (occupational) NMSC.

UV imaging reveals facial areas that are prone to skin cancer are disproportionately missed during sunscreen application

Application of sunscreen is a widely used mechanism for protecting skin from the harmful effects of UV light. However, protection can only be achieved through effective application, and areas that are routinely missed are likely at increased risk of UV damage. Here we sought to determine if specific areas of the face are missed during routine sunscreen application, and whether provision of public health information is sufficient to improve coverage. To investigate this, 57 participants were imaged with a UV sensitive camera before and after sunscreen application: first visit; minimal pre-instruction, second visit; provided with a public health information statement. Images were scored using a custom automated image analysis process designed to identify areas of high UV reflectance, i.e. missed during sunscreen application, and analysed for 5% significance. Analyses revealed eyelid and periorbital regions to be disproportionately missed during routine sunscreen application (median 14% missed in eyelid region vs 7% in rest of face, p<0.01). Provision of health information caused a significant improvement in coverage to eyelid areas in general however, the medial canthal area was still frequently missed. These data reveal that a public health announcement-type intervention could be effective at improving coverage of high risk areas of the face, however high risk areas are likely to remain unprotected therefore other mechanisms of sun protection should be widely promoted such as UV blocking sunglasses.

A 13-Year Retrospective Study of Basal Cell Carcinoma in a Canadian Dermatology Practice: A Comparison Between Anatomical Location and Histopathologic Subtypes

BACKGROUND

It is unknown whether the histologic subtypes of basal cell carcinoma (BCC) arise from a common progenitor cell or whether other factors play a role in their development.

OBJECTIVE

To investigate the relationship between the different BCC histopathologic subtypes and anatomical distribution of BCCs in a Canadian dermatology practice.

METHODS

The charts of all patients diagnosed with BCC between 1993 and 2005 from a single private dermatology practice in Vancouver, Canada, were reviewed. Descriptive data analysis was undertaken to look at the distribution of histologic subtypes based on age, gender, and anatomical location.

RESULTS

Nodular BCCs accounted for 58% of all tumors. Sixty-six percent of these were situated on the head/neck (odds ratio [OR] = 3.0, 95% confidence interval [CI] = 2.1-4.3, P < .0001). Infiltrative (OR = 2.4, 95% CI = 1.5-4.1, P = .0003) and superficial BCCs were more common in women (OR = 3.7, 95% CI = 2.5-5.7, P < .0001), affected the trunk (OR = 3.2, 95% CI = 2.1-4.9, P < .0001), and appeared in younger individuals (OR = 1.8, 95% CI = 1.2-2.7, P = .004).

CONCLUSION

Our results show a preference of distinct BCC subtypes for certain anatomical locations.

Basal cell carcinoma in farmers: an occupation group at high risk

Introduction

Skin cancer is the most commonly diagnosed cancer type worldwide, and 80 % of skin cancers are basal cell carcinoma (BCC). The main risk factor for developing BCC is exposure to ultraviolet radiation (UVR), particularly high-dose exposure at a young age. Outdoor workers, particularly farmers, are at high risk of developing BCC. However, studies of BCC in this population are scant.

Objective

To comprehensively evaluate all cases of BCC of the head and neck region treated during the years 2007–2013 at our hospital in Poland, and to compare the tumour characteristics in farmers to non-farmers.

Materials and methods

Retrospective analysis of 312 patients treated for head and neck BCC during the study period (2007–2013).

Results

Most patients (198 cases; 63 %) were males, with 114 females (37 %). Median age was 73 years (range 32–96 years). The most common tumour location was the nose and cheek (114 pts; 37 %) followed by the auricle (82 pts; 26 %), lips (54 pts; 18 %), scalp (26 pts; 8 %), and eye (36 pts; 12 %). The most common disease stage on presentation was stage T2 (104 pts, 33 %), followed by stage T1 (79 pts; 25 %), stage T3 (89 pts; 28 %), and stage T4 (40 pts; 14 %). By occupation, farmers accounted for 33 % of all patients (102 of 312 pts). The most common tumour localisations in the farmer subgroup were the nose and cheek (50 pts; 49 %; p < 0.001; odds ratio [OR] 2.19; 95 % confidence interval [CI] 1.35–3.57), followed by the auricle (32 pts; 31 %), scalp (16 pts; 16 %), ocular region (3 pts; 3 %), and lips (1 pt; 1 %). Patients in the farmer group were significantly younger than non-farmers (62 vs. 73 years; p < 0.001; OR 0.90, 95 % CI 0.88–0.93). Farmers were significantly more likely to present disease recurrence (27 vs. 12 % of cases; p < 0.001; OR 5.94; 95 % CI 2.86–12.33).

Conclusion

The results highlight the increased incidence and risk of recurrence of BCC in farmers. It is therefore necessary to consider enhancing educational programmes and other preventative measures in this occupational group and to evaluate the effectiveness of such programmes.

Basal cell carcinoma of the skin (part 2): diagnosis, prognosis and management

Basal cell carcinoma (BCC) is a heterogeneous malignant neoplasm with different biological and clinical behaviors, often slow growing and rarely metastatic and conveying an excellent prognosis. However, BCC is the most frequent skin cancer worldwide and can cause great morbidity, as most occur in high visible areas of the body, often relapse and may invade and destroy local tissues. This review aims to present a concise and updated overview of BCC histopathology and clinical presentation and progression. We also present a summary of currently available treatment options and some of the new promising agents.

Early-onset basal cell carcinoma and indoor tanning: a population-based study

OBJECTIVE

Indoor tanning with UV radiation-emitting lamps is common among adolescents and young adults. Rising incidence rates of basal cell carcinoma (BCC) have been reported for the United States and elsewhere, particularly among those diagnosed at younger ages. Recent epidemiologic studies have raised concerns that indoor tanning may be contributing to early occurrence of BCC, and younger people may be especially vulnerable to cancer risk associated with this exposure. Therefore, we sought to address these issues in a population-based case-control study from New Hampshire.

METHODS

Data on indoor tanning were obtained on 657 cases of BCC and 452 controls ≤50 years of age.

RESULTS

Early-onset BCC was related to indoor tanning, with an adjusted odds ratio (OR) of 1.6 (95% confidence interval, 1.3-2.1). The strongest association was observed for first exposure as an adolescent or young adult, with a 10% increase in the OR with each age younger at first exposure (OR per year of age ≤23 = 1.1; 95% confidence interval, 1.0-1.2). Associations were present for each type of device examined (ie, sunlamps, tanning beds, and tanning booths).

CONCLUSIONS

Our findings suggest early exposure to indoor tanning increases the risk of early development of BCC. They also underscore the importance of counseling adolescents and young adults about the risks of indoor tanning and for discouraging parents from consenting minors to this practice.

Ultraviolet Radiation and the Skin

Ultraviolet radiation (UVR) has many interactions with the skin, which are explored in detail in this review. Both ultraviolet A (UVA) and ultraviolet B (UVB) wavelengths are absorbed by chromophores in the skin, resulting in important biologic effects. Exposure to UVR can result in sunburn, immediate and delayed skin pigmentation, photoaging, and immunosuppression. In addition, exposure to UVA and UVB is an important risk factor for melanoma, squamous cell carcinoma, and basal cell carcinoma. Because endogenous vitamin D synthesis requires UVB, concerns have been raised about the possibility that photoprotection might contribute to vitamin D deficiency; however, vitamin D supplementation is a safer and more reliable method for maintaining adequate vitamin D levels than UVR exposure. Protection from UVR is critical and involves several factors. These elements include sun avoidance during peak hours of UVR exposure (10 am to 2 pm), proper application of a broad-spectrum sunscreen with adequate sun protection factor, and wearing protective clothing, a wide-brimmed hat, and protective eyewear. Indoor tanning is a high-risk activity that is likely contributing to recent increases in melanoma and nonmelanoma skin cancer in young women, and efforts are ongoing to ban minors from engaging in indoor tanning.

Indoor tanning and non-melanoma skin cancer: systematic review and meta-analysis

OBJECTIVE

To synthesise the literature on indoor tanning and non-melanoma skin cancer.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed (1966 to present), Embase (1974 to present), and Web of Science (1898 to present).

STUDY SELECTION

All articles that reported an original effect statistic for indoor tanning and non-melanoma skin cancer were included. Articles that presented no data, such as review articles and editorials, were excluded, as were articles in languages other than English.

DATA EXTRACTION

Two investigators independently extracted data. Random effects meta-analysis was used to summarise the relative risk of ever use versus never use of indoor tanning. Dose-response effects and exposure to indoor tanning during early life were also examined. The population attributable risk fraction for the United States population was calculated.

RESULTS

12 studies with 9328 cases of non-melanoma skin cancer were included. Among people who reported ever using indoor tanning compared with those who never used indoor tanning, the summary relative risk for squamous cell carcinoma was 1.67 (95% confidence interval 1.29 to 2.17) and that for basal cell carcinoma was 1.29 (1.08 to 1.53). No significant heterogeneity existed between studies. The population attributable risk fraction for the United States was estimated to be 8.2% for squamous cell carcinoma and 3.7% for basal cell carcinoma. This corresponds to more than 170 000 cases of non-melanoma skin cancer each year attributable to indoor tanning. On the basis of data from three studies, use of indoor tanning before age 25 was more strongly associated with both squamous cell carcinoma (relative risk 2.02, 0.70 to 5.86) and basal cell carcinoma (1.40, 1.29 to 1.52).

CONCLUSIONS

Indoor tanning is associated with a significantly increased risk of both basal and squamous cell skin cancer. The risk is higher with use in early life (<25 years). This modifiable risk factor may account for hundreds of thousands of cases of non-melanoma skin cancer each year in the United States alone and many more worldwide. These findings contribute to the growing body of evidence on the harms of indoor tanning and support public health campaigns and regulation to reduce exposure to this carcinogen.

Role of solar UVB irradiance and smoking in cancer as inferred from cancer incidence rates by occupation in Nordic countries

A large body of evidence indicates that solar ultraviolet-B (UVB) irradiance and vitamin D reduce the risk of incidence and death for many types of cancer. However, most of that evidence comes from midlatitude regions, where solar UVB doses are generally high in summer. Data on cancer standardized incidence ratios (SIRs) by sex and 54 occupation categories based on 1.4 million male and 1.36 million female cancer cases for 1961–2005 in the five Nordic countries provide the basis for an ecological study of the role of solar UVB in the risk of many types of cancer at high latitudes. Lip cancer SIRs less lung cancer SIRs for men was the best index of solar UVB dose, which was weakly inversely correlated with both melanoma and nonmelanoma skin cancer (NMSC) SIRs. Lung cancer SIRs were used as the index of the effects of smoking. For men, the UVB index was significantly inversely correlated with 14 types of internal cancer—bladder, breast, colon, gallbladder, kidney, laryngeal, liver, lung, oral, pancreatic, pharyngeal, prostate, rectal and small intestine cancer. For women, the same UVB index was inversely correlated with bladder, breast and colon cancer. These results generally agree with findings from other studies. These results provide more support for the UVB-vitamin D-cancer hypothesis and suggest that widespread fear of chronic solar ultraviolet (UV) irradiance may be misplaced.

Beneficial effects of UV radiation other than via vitamin D production

Most of the positive effects of solar radiation are mediated via ultraviolet-B (UVB) induced production of vitamin D in skin. However, several other pathways may exist for the action of ultraviolet (UV) radiation on humans as focused on in this review. One is induction of cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning). UVB-induced, delayed tanning (increases melanin in skin after several days), acts as a sunscreen. Several human skin diseases, like psoriasis, vitiligo, atopic dermatitis and localized scleroderma, can be treated with solar radiation (heliotherapy) or artificial UV radiation (phototherapy). UV exposure can suppress the clinical symptoms of multiple sclerosis independently of vitamin D synthesis. Furthermore, UV generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health. UVA-induced NO may also have antimicrobial effects and furthermore, act as a neurotransmitter. Finally, UV exposure may improve mood through the release of endorphins.

Cutaneous melanoma attributable to sunbed use: systematic review and meta-analysis

OBJECTIVE

To estimate the burden of melanoma resulting from sunbed use in western Europe.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, ISI Web of Science (Science Citation Index Expanded), Embase, Pascal, Cochrane Library, LILACS, and MedCarib, along with published surveys reporting prevalence of sunbed use at national level in Europe.

STUDY SELECTION

Observational studies reporting a measure of risk for skin cancer (cutaneous melanoma, squamous cell carcinoma, basal cell carcinoma) associated with ever use of sunbeds.

RESULTS

Based on 27 studies ever use of sunbeds was associated with a summary relative risk of 1.20 (95% confidence interval 1.08 to 1.34). Publication bias was not evident. Restricting the analysis to cohorts and population based studies, the summary relative risk was 1.25 (1.09 to 1.43). Calculations for dose-response showed a 1.8% (95% confidence interval 0% to 3.8%) increase in risk of melanoma for each additional session of sunbed use per year. Based on 13 informative studies, first use of sunbeds before age 35 years was associated with a summary relative risk of 1.87 (1.41 to 2.48), with no indication of heterogeneity between studies. By using prevalence data from surveys and data from GLOBOCAN 2008, in 2008 in the 15 original member countries of the European Community plus three countries that were members of the European Free Trade Association, an estimated 3438 cases of melanoma could be attributable to sunbed use, most (n=2341) occurring among women.

CONCLUSIONS

Sunbed use is associated with a significant increase in risk of melanoma. This risk increases with number of sunbed sessions and with initial usage at a young age (<35 years). The cancerous damage associated with sunbed use is substantial and could be avoided by strict regulations.

[Cutaneous malignancies in occupationally-induced scars]

BACKGROUND

The occurrence of neoplasms in injury scars--as consequence of occupational accidents--may lead to compensation according to the statutory accident insurance regulations. According to newer regulatory attempts in occupational dermatology, certain criteria have to be met before the diagnosis of a neoplasm induced by a scar is accepted and compensation is due.

MATERIAL AND METHODS

Based on a retrospective analysis of 217 dermatological claim files between 2007 and 2009 of the IPA (including 22 follow-ups), medical opinions on neoplasms developing in possible occupational scars were re-evaluated using criteria of the German social accident insurance and the Bamberg medical bulletin, part II (Bamberger Merkblatt, BM II) to see how well they qualified for recognition as an occupational or accident-related disorder.

RESULTS

Three cases were identified where a neoplasm was suspected of having developed in an occupationally-related scar. One of the insured events entitled for compensation. Following the guidelines of the BM II, this case was approved as an occupational disease secondary to injuries with resultant reduction in earning capacity, whereas the others did not meet the requirements.

CONCLUSIONS

Two problems in evaluating malignant tumors in occupational scars are the long latency period and the documentation of a scar. The tumor excision specimen should be histologically re-examined to document the presence of an associated scar.

Epidemiology of basal cell carcinoma

Basal cell carcinoma is the most common malignant neoplasm in humans and its incidence has increased over the last decades. Its high frequency significantly burdens the health system, making the disease a public health issue. Despite the low mortality rates and the rare occurrence of metastases, the tumor may be locally invasive and relapse after treatment, causing significant morbidity. Exposure to ultraviolet radiation is the main environmental risk factor associated with its cause. However, other elements of risk are described, such as light skin phototypes, advanced age, family history of skin carcinoma, light eyes and blond hair, freckles in childhood and immunosuppression. Behavioral aspects such as occupational sun exposure, rural labor and sunburns at a young age also play a role. Between 30% and 75% of the sporadic cases are associated with patched hedgehog gene mutation, but other genetic changes are also described. The tumor is commonly found in concomitance with skin lesions related to chronic sun exposure, such as actinic keratoses, solar lentigines and facial telangiectasia. The prevention of basal cell carcinoma is based on the knowledge of risk factors, early diagnosis and treatment, as well as on the adoption of specific measures, particularly in susceptible populations. The authors present a review of the epidemiology of basal cell carcinoma.

Indoor tanning and risk of early-onset basal cell carcinoma

BACKGROUND

Despite an increase in incidence of basal cell carcinoma (BCC) among young people and the ubiquity of indoor tanning in this population, few epidemiologic studies have investigated this exposure-disease relationship.

OBJECTIVE

We sought to evaluate the association between indoor tanning and early-onset BCC.

METHODS

Patients with BCC (n = 376) and control subjects with minor benign skin conditions (n = 390) who were younger than 40 years of age were identified through Yale Dermatopathology. Participants provided information on ever indoor tanning, age of initiation, frequency, duration, burns while tanning, and type of tanning device during an in-person interview. We calculated odds ratios (OR) and 95% confidence intervals (CI) using multivariate logistic regression with never indoor tanners as the referent group.

RESULTS

Ever indoor tanning was associated with a 69% increased risk of early-onset BCC (95% CI 1.15-2.48). This association was stronger among females (OR 2.14, 95% CI 1.31-3.47), for multiple BCCs (OR 2.16, 95% CI 1.26-3.70), and for BCCs on the trunk and extremities (OR 2.81, 95% CI 1.57-5.02). Risk increased dose dependently with years using regular indoor tanning devices (P trend = .003), number of overall burns (P trend < .001), and burns to biopsy site (P trend < .001) from indoor tanning. Approximately one quarter (27%) of early-onset BCCs (or 43% among women) could be prevented if individuals never tanned indoors.

LIMITATIONS

Potential recall bias of indoor tanning by patients and generalizability of the control population suggest replication in other studies is warranted.

CONCLUSIONS

Indoor tanning was a strong risk factor for early-onset BCC, particularly among females. Indoor tanning should continue to be targeted by both policy-based and behavioral interventions, as the impact on BCC-associated morbidity may be substantial.

[Risk factors for basal cell carcinoma: a study from the national dermatology center of Colombia]

BACKGROUND

Colombia is home to one of the areas with the highest levels of exposure to UV radiation in the world, namely, the Andes Mountains, which stretch along the equator. Recent studies have reported an increase in the incidence of basal cell carcinoma in Colombia, but the risk factors associated with the development of this disease have not been studied.

OBJECTIVE

To determine the risk factors for basal cell carcinoma in patients from the National Dermatology Center of Colombia.

MATERIAL AND METHODS

We performed a case-control study involving 406 individuals, and analyzed sociodemographic, epidemiological, and clinical factors using multiple logistic regression.

RESULTS

The following risk factors were identified: skin phototypes I to III (odds ratio [OR], 15.4), family history of skin cancer (OR, 5.8), past history of actinic keratosis (OR, 3.3), continued residence in a rural area after the age of 30 years (OR, 2.96), practice of outdoor sports (OR, 2.67), history of 10 or more episodes of sunburn (OR, 2.3), actinic conjunctivitis (OR, 2.26), and failure to use a hat in childhood (OR, 2.11).

CONCLUSIONS

Different factors specific to Colombia increase the risk of basal cell carcinoma. In particular, the association with phototype III could partly explain the increase in incidence detected in this country. Preventive programs should target the risk groups detected and highlight the importance of basing decisions on local evidence.

Determination of the relationship between Basal cell carcinoma and human papilloma virus, based on immunohistochemistry staining method

Background:

Basal cell carcinoma (BCC) is the most common skin cancer among Caucasians, and in most cases, occurs in the sun-exposed areas. In recent years, in addition to many other etiologies such as exposure to UV radiation, and occasionally xeroderma pigmentosa, burns, tattoos, and pox scars, human papillomavirus (HPV) is also considered to have an etiologic role. Different studies were conducted with varied results in this regard.

Aims:

We evaluate this plausible relationship between HPV and BCC by means of immunohistochemistry (IHC) staining method.

Methods:

This is an analytic cross-sectional study in which 160 samples were selected randomly consisting of 80 BCC lesions and 80 safe margins. Sampling was done among paraffin-embedded blocks in pathology ward of Kashani and Alzahra hospitals, Isfahan-Iran, from 2004-2007. A section of each block was IHC stained for HPV immunoreactivity (DAKO, Denmark). This was followed by microscopic evaluation in terms of being positive or negative.

Results:

Fifty seven point five percent of the samples belonged to men and the others to women. In 10%, HPV marker was positive, both in lesion and margin. In 83.8% neither the lesions nor the margins were immunoreactive for HPV. Only in 5 cases (6.3%) the lesion was positive and the margin was negative for this marker. There was no case of immunoreactivity for HPV marker in margins, while it was negative in lesions. Our study results followed by McNemar analysis did not show a significant relationship between BCC incidence and HPV existence. This was consistent in both genders (P > 0.05, power > 90%).

Conclusion:

In this study we did not find a significant relationship between BCC and HPV, but based on review of articles it appears that large multicentric studies are to be conducted in this regard.

Corrective eyeglasses and medial canthal basal cell carcinoma: a case-control study

BACKGROUND

Corrective eyeglasses are frequently worn by adults, particularly at older ages. Their lenses and frames provide ultraviolet protection. Medial canthal basal cell carcinomas are infrequent (3-8%), and their relation with the use of corrective glasses was not yet investigated.

OBJECTIVES

To assess the prevalence of corrective eyeglasses use in individuals with medial canthal basal cell carcinoma.

METHODS

Case-control study using two controls matched by age, gender, and ethnicity for each case. Cases were patients with medial canthal basal cell carcinoma, and controls were patients with basal cell carcinoma elsewhere on the face. The prevalence of major risk variables was estimated and adjusted by conditional multiple logistic regression.

RESULTS

Fifty cases and 100 controls were assessed. The mean patient age was 69.7 years, and 54% of the subjects were females. No difference regarding the eyeglasses use or use duration was found between groups. However, when visual defects were separately evaluated, eyeglasses for myopia correction were independently associated with lower risk of medial canthal basal cell carcinoma development (OR=0.26; P=0.03), what can be related to long term local photoprotection.

CONCLUSION

The use of eyeglasses for myopia correction is associated with lower prevalence of medial cantal basal cell carcinoma. Risk-reducing mechanisms should be elucidated.

Risk factors for basal cell carcinoma: Results from the case-control study

The aim of the present case-control study was to assess the risk factors for Basal cell carcinoma (BCC) in the Montenegrin population. The study group was comprised of 100 consecutive patients with a diagnosis of BCC, while the control group consisted of patients who did not present skin cancer and who were individually matched to the cases by sex and age. The increased risk for BCC was associated with: the presence of nevi (odds ratio [OR] = 3.77; 95% confidence interval [CI] = 1.12–12.73), type of skin concerning to burn rather than to tan after repeated sun exposure in childhood or adolescence (OR = 3.14; 95% CI = 1.59–6.18), the skin reaction to burn after two or more hours of sunlight during childhood or adolescence (OR = 4.53; 95% CI = 2.37–8.63), the number of severe and painful sunburns during their lifetime(OR = 3.52; 95% CI = 1.68–7.38), outdoor work during the summer-time (OR = 2.73; 95% CI = 1.00–7.45), occupational exposure to chemicals (OR = 17.89; 95% CI = 2.82–113.52), history of eczema (OR = 4.17; 95% CI = 1.53–11.39), and history of previous BCC (OR = 3.86; 95% CI = 1.40–10.65). Our study confirms the role of environmental and constitutional factors in development of BCC.

Basal cell carcinoma: what's new under the sun

Basal cell carcinoma (BCC) is the most common skin cancer in white populations with an increasing incidence worldwide, thereby imposing an important public health problem. Its etiology is still unclear, but existing data indicate that the risk for BCC development is of multifactorial origin and results from the interplay of both constitutional and environmental factors. Yet, UV radiation (UVR) is believed to be the predominant causative risk factor in the pathogenesis of BCC. For years, BCC and squamous cell carcinoma (SCC) have been grouped together as "nonmelanoma skin cancer." However, it seems that there are considerable biologic differences between BCC and SCC, and thus each type of epithelial cancer should be addressed separately. The present review provides an overview of the intriguing etiologic link of BCC with UVR and attempts a comprehensive review of recent epidemiologic and molecular evidence that supports this association.

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

PURPOSE

The present review is aimed at providing an overview of skin cancer with particular focus on occupational concern and giving evidence-based recommendation for effective prevention at workplace.

METHODS

We performed a systematic search of literature using PubMed and the Cochrane Library.

RESULTS

Outcome of preventive strategies depends either on efficacy of the strategy itself but also on acceptance and implementation of protective means among the persons at possible risk for hazardous health effects. Epidemiological studies have reported significantly more non-melanoma skin cancer in men than in women. Life-style choices and difference in immunosuppression play a major role in this gender disparity. Tumor biology of skin cancer is diverging: severe blistering sunburns corresponding to intermittent intense UV exposures are associated with an increased risk for both melanoma and basal cell carcinoma (BCC); whereas the risk of squamous cell carcinoma (SCC) and actinic keratoses (AK) is strongly associated with chronic UV exposure. Several clinical trials give evidence that long-term use of sunscreen prevents the appearance of non-melanotic skin cancer such as AK and SCC, but not of BCC. All technical and organizing measures aimed at reducing UV exposure at workplace belong to first-line prevention; however, there is much room for improvement. The efficacy of personal protection means (second-line strategy) strongly depends on the workers' compliance which is quite low at workplace.

CONCLUSION

Evidence-based data confirming the benefit of sun protective strategies are scarce, general recommendations are mainly based on the avoidance of UV radiation being identified as potential risk factor for non-melanoma skin cancer in epidemiological studies. Occupational screenings should include regular interventions aimed at enhancing a clear understanding of risk factors for individuals and finally improving the acceptance and maintenance for UV-protective means at workplace.