Sun exposure and large numbers of common and atypical melanocytic naevi: an analytical study in a southern European population

[Multiple sclerosis and melanoma]

Multiple sclerosis (MS) is a chronic autoimmune progressive demyelinating disease of the central nervous system, mainly in young people. The clinical picture of MS has a variety of neurological symptoms, which manifests itself during periods of exacerbation or progression and stabilizes at the moments of remission. The widespread introduction of new drugs with immunosuppressive and immunomodulatory mechanisms of action has led to the development of special risk management plans for monitoring patients during therapy and preventing adverse events and new comorbid conditions. This article presents a review of the literature and a case report on the combination of MS and melanoma in patients. Melanoma can rarely develop in patients treated with DMD, so it is necessary to introduce such a specialist in dermatology and venereology into a multidisciplinary team.

Evaluating the effect of tanning response to sun exposure on the risk of skin diseases through Mendelian randomization

Background: Until now, the relevance of the tanning response to sun exposure and skin diseases has incomplete and inconsistent epidemiological observations. In this case, it is valuable to find out the causality of tanning response to sun exposure and skin diseases, and take a step further toward developing effective therapies as well as prevention methods.

Methods: We investigated the causal effect of tanning response to sun exposure on 10 major skin diseases that have been studied in recent large-scale genome-wide association studies (GWASs). Significant independent genetic variants from large-scale GWAS on ease of skin tanning (N = 453,065) are selected as the effective instrumental variables (IVs). For each skin disease, we extracted the summary statistics of those IVs (or their proxies) from the corresponding skin disease-GWAS as the valid IVs. Mendelian randomization (MR) was further performed to evaluate the causal association of ease of skin tanning with each of the skin diseases using different statistical methods, including inverse-variance weighted (IVW), the weighted median, and MR-Egger. Sensitivity analysis was also conducted to evaluate the effect of horizontal pleiotropy and heterogeneity.

Results: We observe significant associations between six skin diseases with tanning response to sun exposure with adjusted p-value derived by IVW less than 0.05 and with nominal p value less than 0.05 at the same time derived by either MR-Egger or weighted median. The six skin diseases include actinic keratosis (IVW FDR = 1.71E-40, MR Egger p-value = 3.46E-22), seborrhoeic keratosis (IVW FDR = 2.97E-4, MR Egger p-value = 1.06E-3), blepharochalasis (IVW FDR = 1.30E-3, MR Egger p-value = 2.91E-4), seborrhoeic dermatitis (IVW FDR = 1.29E-2, MR Egger p-value = 1.23E-2), malignant melanoma of skin (IVW FDR = 2.95E-2, MR Egger p-value = 1.91E-2), and freckles (IVW FDR = 2.95E-2, weighted median p-value = 1.02E-3). Interestingly, we find increased trends of developing all of the six skin diseases with increased tanning response to sun exposure (beta values are positive using IVW, MR-egger, and weighted median methods). We also replicate the association on three skin diseases using an independent outcome GWAS cohort, including malignant melanoma of the skin (replication IVW p-value = 2.13E-39), actinic keratosis (replication IVW p-value = 4.64E-32), and seborrhoeic keratosis (replication IVW p-value = 1.79E-3).

Conclusion: Our observation shows that the tanning response to sun exposure is positively correlated with the development of skin diseases in people of European descent by Mendelian randomization studies. But randomized controlled trials are still needed to add proof to our observations.

High variability in anatomic patterns of cutaneous photodamage: a population-based study

BACKGROUND

Skin cancer is strongly associated with photodamaged skin, but body sites are often referred to as 'exposed' or 'unexposed' to sun without recognizing extent of site-specific variation.

OBJECTIVES

To assess whole-body patterns of photodamage in an Australian population.

METHODS

A random sample of adult residents of Queensland underwent imaging across 10 body sites. Photodamage was graded from images using an ordinal photonumeric scale. We used cluster analysis to identify whole-body photodamage patterns and prevalence proportion ratios (PPRs) to assess associated factors.

RESULTS

Of 190 adults (median age 52; 58% males), 58% showed severe or moderate-to-severe photodamage on most body sites. A higher proportion of woman had severe photodamage on the arms (upper: P = 0.002, lower: P = 0.034). A higher proportion of men had moderate or severe photodamage on the lower back (P = 0.004). We identified four photodamage patterns: 'severe general' (n = 24, 13%), 'moderate-severe general' (n = 86, 45%), 'moderate-severe v-neck' (n = 40, 21%) and 'mild-moderate upper body' (n = 12, 6%). All participants with 'severe-general' photodamage were >50 years and more likely to have past skin cancer (PPR: 2.54, 95% CI: 1.44-4.49) than those with 'moderate-severe v-neck' photodamage. Those with 'moderate-severe general' photodamage showed similar associations and were more likely female (PPR: 1.33, 95% CI: 1.04-1.69). Past or current smoking was associated with having higher levels of photodamage, with no smokers in those with 'mild-moderate upper body' photodamage.

CONCLUSIONS

Moderate-to-severe photodamage across much of the body is common in Queensland adults and associated with age, sex, past skin cancer and smoking. Assuming a universal pattern of site-specific sun exposure could lead to spurious correlations, while accurate and objective assessment of site-specific photodamage can add to understanding of the development of sun-associated skin cancers, in particular site-specific skin carcinogenesis. Additionally, degree of site-specific photodamage has the potential to assist skin cancer screening.

Differences in clinicopathological features and distribution of risk factors in Italian melanoma patients

BACKGROUND

No studies are available in the literature on the distribution of different melanoma features and risk factors in the Italian geographical areas.

OBJECTIVE

To identify the differences in clinical-pathological features of melanoma, the distribution of risk factors and sun exposure in various Italian macro-areas.

METHODS

Multicentric-observational study involving 1,472 melanoma cases (713 north, 345 centre, 414 south) from 26 referral centres belonging to the Italian Multidisciplinary Group for Melanoma.

RESULTS

Melanoma patients in northern regions are younger, with thinner melanoma, multiple primaries, lower-intermediate phototype and higher counts of naevi with respect to southern patients; detection of a primary was mostly connected with a physician examination, while relatives were more involved in the south. Northern patients reported a more frequent use of sunbeds and occurrence of sunburns before melanoma despite sunscreen use and a lower sun exposure during the central hours of the day.

CONCLUSIONS

The understanding of differences in risk factors distribution could represent the basis for tailored prevention programmes.

Factors associated with the prevalence of atypical nevus in a Mediterranean pigmented skin lesion clinic

Atypical melanocytic nevi constitute central risk factor and are precursor lesions for cutaneous melanoma. Data regarding factors associated with their prevalence are mainly derived from fair-skinned populations, whereas little is known regarding their epidemiological associations in darker-skinned, chronically sun-exposed populations. The aim of this study was to identify risk factors for the occurrence of at least one atypical nevus on Crete, the southernmost island of Greece. This hospital-based case-control study included 143 patients and 189 controls with at least one atypical nevus presented at the pigmented skin lesion clinic of the University of Crete. All participants were interviewed and underwent complete skin examination by the same two experienced dermatologists. Multivariate logistic regression analysis was used to adjust for potential confounders. In the multivariate analysis, common melanocytic nevi [odds ratio (OR): of 2.2, 7.5, and 58.9 for the presence of 11-25, 26-100, and >100 common nevi, respectively] and recreational sun exposure (OR: 4.4) increased significantly the risk of the presence of atypical nevus. A decreased risk for atypical nevi was related to an increasing age (OR: 0.96/age), and professional sun exposure (OR: 0.5). Intermittent, recreational sun exposure is mainly associated with the prevalence of atypical nevi in our sample and this effect does not depend on skin phototype. Promotion of sun protection, especially in patients with high numbers of common nevi, might serve as a measure to prevent the development of atypical nevi.

Neonatal blue light phototherapy and melanocytic nevi: a twin study

BACKGROUND

Neonatal blue light phototherapy (NBLP) has been widely and successfully used for the treatment of neonatal jaundice to reduce the plasma concentration of bilirubin and, hence, to prevent kernicterus. Only a few and controversial data are available in the literature as to how NBLP influences melanocytic nevus development.

OBJECTIVE

Our goal was to conduct a twin study with the aim of better understanding the role of NBLP in melanocytic nevus development. We also investigated the roles of other environmental and constitutional factors in nevus formation.

METHODS

Fifty-nine monozygotic and dizygotic twins were included in this cross-sectional study. One of the twin members received NBLP, and the other did not. A whole-body skin examination was performed to determine the density of melanocytic skin lesions. The prevalence of benign pigmented uveal lesions was evaluated during a detailed ophthalmologic examination. A standardized questionnaire was used to assess data relating to constitutional, sun-exposure, and other variables. To search for possible gene-environmental interactions involved in the appearance of pigmented lesions, the melanocortin 1 receptor variants and the I439V polymorphism of histidine ammonia-lyase genes were also determined in the enrolled twins.

RESULTS

NBLP was associated with a significantly higher prevalence of both cutaneous and uveal melanocytic lesions. No association was found between the examined gene polymorphisms and the number of pigmented alterations in the examined study group.

CONCLUSIONS

Our data suggest that NBLP could well be a risk factor for melanocytic nevus development. Phototherapy with blue-light lamps is a standard and essential therapeutic modality in neonatal care; therefore, additional in vivo and in vitro studies are necessary to establish its potential long-term adverse effects.

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.

[The prevalence of melanocytic naevi among teenagers]

Malignant melanoma is an increasing public health problem worldwide; accordingly, identification of the constitutional and environmental factors which contribute to the development of the disease, and hence identification of the individuals at high risk of melanoma, are indispensable steps in all primary prevention efforts.

AIM

The objective of the present study was to assess the prevalence of different pigmented lesions among schoolchildren, and to investigate their relationship with phenotypic pigmentary characteristics, sun exposure and other factors.

METHODS

A cross-sectional study was performed in two secondary schools in Szeged, Hungary. A total of 1320 schoolchildren, aged 14 to 18 years, underwent a whole-body skin examination. A standardized questionnaire was used to collect data on phenotypic, sun exposure and other variables.

RESULTS

Between 1-10 common melanocytic naevi were found in 27% of the participants, and naevi numbers were in the range between 10-100 in 67%. 5.4% of them had more than 100 common melanocytic naevi. The prevalence of clinically atypical naevi was 24.3%. Congenital naevi were detected in 6.2% of the schoolchildren. A statistically significant association was found between the number of pigmented lesions and gender, hair colour, eye colour, skin phototype, the history of severe painful sunburns, and the family history of a large number of melanocytic naevi.

CONCLUSIONS

Our study population displayed a markedly high prevalence of clinically atypical melanocytic naevi. Moreover, a considerable proportion of the investigated individuals had multiple common melanocytic naevi. Since the presence of large number of melanocytic naevi is a strong predictor for future melanoma development, health educational programmes on melanoma prevention should be aimed at young age groups.

The prevalence of melanocytic naevi among schoolchildren in South Hungary

BACKGROUND

Malignant melanoma is an increasing public health problem worldwide; accordingly, identification of the constitutional and environmental factors which contribute to the development of the disease, and hence identification of the individuals at high risk of melanoma, is an indispensable step in all primary prevention efforts.

OBJECTIVES

This paper aims to assess the prevalence of different pigmented lesions among schoolchildren and to investigate their relationship with phenotypic pigmentary characteristics, sun exposure and other factors.

PATIENTS/METHODS

A cross-sectional study was performed in two secondary schools in Szeged, Hungary. A total of 1320 schoolchildren, aged 14 to 18 years, underwent a whole-body skin examination. A standardized questionnaire was used to collect data on phenotypic, sun exposure and other variables.

RESULTS

One to 10 common melanocytic naevi were found in 27% of the participants, and the naevus numbers were in the range of 10-100 in 67%; 5.4% of them had more than 100 common melanocytic naevi. The prevalence of clinically atypical naevi was 24.3%. Statistically significant associations were found between the number of pigmented lesions and gender, hair colour, eye colour, skin phototype, a history of severe painful sunburns and a family history of a large number of melanocytic naevi.

CONCLUSION

Our study population displayed a markedly high prevalence of clinically atypical melanocytic naevi. Moreover, a considerable proportion of the investigated individuals had multiple common melanocytic naevi. Since the presence of a large number of melanocytic naevi is a strong predictor for future melanoma development, health educational programmes on melanoma prevention should be aimed at young age groups.

Case-control study to identify melanoma risk factors in the Belgian population: the significance of clinical examination

BACKGROUND

Although numerous studies have evaluated risk factors associated with cutaneous malignant melanoma (CMM), no such study has been carried out in Belgium.

OBJECTIVES

To identify individuals who are at high risk of developing malignant melanoma in Belgium, which could enhance the efficacy of screening interventions and avoid unnecessary skin inspections. STUDY DESIGN/SETTING/SUBJECTS: We prospectively included patients who were diagnosed with invasive malignant melanoma between 1998 and 2001 at the Department of Dermatology in a case-control study. Controls were selected from the outpatient dermatology clinic. Participants were interviewed and clinically examined by a dermatologist. We asked questions concerning most known risk factors associated with malignant melanoma such as phenotypical and skin characteristics, and environmental and lifestyle exposures. To adjust for confounding variables and to estimate odds ratios (ORs) and 95% confidence intervals (CIs), a multivariate model was used.

RESULTS

Although sunburn in childhood and substantial occupational solar exposure were modestly, but significantly, associated with malignant melanoma risk, clinical examination yielded several stronger risk factors. In a multivariate model, which adjusted for age, gender and skin phototype, phenotypical characteristics such as skin, hair and eye colour were significantly associated with the development of malignant melanoma. In the multivariate model, people with three or more atypical naevi were at more than 10-fold risk of developing a malignant melanoma (> or = 3 atypical naevi; adjusted OR = 11.40, 95% CI = 4.79-17.53) compared to those without an atypical naevus. The presence of one or more palpable naevi on the upper extremities or having solar lentigines increased the odds of developing malignant melanoma at least twofold.

CONCLUSIONS

In Belgium, risk factors associated with malignant melanoma appear to be in accordance with previous studies. To assess peoples' risk profile, clinical skin examination is likely to yield the most important sporadic malignant melanoma risk factors. Therefore, focusing screening campaigns on individuals with predefined findings on skin self-examination may increase its efficacy.

The effect of sun exposure in determining nevus density in UK adolescent twins

We report a study of 221 teenage twin pairs to examine the genetic and environmental determinants of nevi representing the most potent phenotypic risk factor for melanoma. Our published heritability analysis estimated that nevi are mainly genetically determined. In this paper we examine the role of sun exposure. We report a correlation between nevus density and sun exposure, particularly that acquired in hotter countries than in the UK (mean nevus density 41 per m2 in those in the highest quartile of exposure vs 24 per m2 in those with no exposure, p<0.0001). We were not able to demonstrate a protective effect for either sun protection cream or shirt wearing. By including phenotypic variables and reported sun exposure into the heritability analysis, we conclude that 66% of the total variance of nevus count is attributable to genetic effects: 7% associated to eye color, 6% to hair color, and 1% to reported skin type, which leaves 52% as to yet unidentified genetic factors. Of the 25% of variation attributable to environmental influences, one-third is estimated to be because of sun exposure on hot holidays.

Ectopic expression of tyrosinase increases melanin synthesis and cell death following UVB irradiation in fibroblasts from familial atypical multiple mole and melanoma (FAMMM) patients

Patients with familial atypical multiple mole and melanoma (FAMMM) [so-called familial dysplastic naevus syndrome (FDNS)] have a high risk for the development of malignant melanoma. The underlying gene defect has an autosomal dominant inheritance with variable expression and incomplete penetrance. Fibroblasts derived from FAMMM patients have high sensitivity to UVC and mutagens, e.g. 4-nitroquinoline-1-oxide. We were interested in identifying how the combination of inherent sensitivity to UV light and abnormal melanin synthesis interacts in the development of melanoma in FAMMM patients. Intermediates of melanin synthesis produce free radicals that are toxic to cells. Atypical moles (dysplastic naevi) are engaged in the biosynthesis of abnormal melanin pigments. This study examined whether there was any abnormal melanin pigmentation or cell damage after the ectopic expression of tyrosinase in fibroblasts from FAMMM patients when compared with fibroblasts from normal subjects. Fibroblasts from FAMMM patients (3012T and 3072T) were associated with a higher sensitivity than normal human fibroblasts to the toxicity of UVB. When cells were infected with tyrosinase-expressing adenovirus (Ad-HT) and irradiated with UVB, FAMMM fibroblasts showed higher tyrosinase activity, produced more melanin pigments and were degraded more significantly than normal human fibroblasts. Western blot analysis revealed that Ad-HT-infected 3072T produced a larger amount of tyrosinase protein than did Ad-HT-infected normal fibroblasts after UVB irradiation. Our findings suggest: (1) that FAMMM fibroblasts have an unknown machinery which enhances tyrosinase expression by UVB irradiation; and (2) that the resulting increase in melanin synthesis affects the cytotoxicity of UVB to FAMMM fibroblasts. All of these processes may be involved in the genomic instability and development of melanoma in FAMMM patients.

Bronzeamento e risco de melanoma cutâneo: revisão da literatura

Estudos epidemiológicos sugerem a relação entre comportamentos relacionados ao bronzeamento e risco elevado de melanoma. Nesse sentido, realizou-se revisão sobre essa temática que abrangeu o período correspondente aos anos de 1977 a 1998. Foram pesquisadas as bases de dados Medline e Embase (Excerpta Medica). A análise mostrou que entre os jovens, apesar do conhecimento sobre os riscos da exposição excessiva à radiação ultravioleta e sobre as práticas visando à proteção da pele, prevalece o hábito de expor-se intencionalmente ao sol. Esse hábito é alimentado por crenças e atitudes em relação ao bronzeado e estimulado por influência do grupo e de pessoas consideradas "referências". As práticas mais freqüentemente adotadas para bronzear a pele apresentam risco elevado para o desenvolvimento de melanoma. Conclui-se que a forma mais eficaz de prevenir o melanoma é divulgar nos meios de comunicação que a pele bronzeada não é saudável, pois foi danificada pela radiação ultravioleta solar; e iniciar campanhas com ações efetivas para mudar comportamentos, naquilo que os motiva e os alimenta.

Long-term dermoscopic follow-up of melanocytic naevi: clinical outcome and patient compliance

BACKGROUND

Digital dermoscopy for the follow-up of melanocytic naevi (MN) is becoming more common in dermatological private practice.

OBJECTIVES

To evaluate the clinical outcome, including the patient's compliance, in a long-term follow-up of single MN.

METHODS

Criteria for the selection of MN for follow-up: clinically suspicious without dermoscopically atypical features, or typical for the patient. Clinical outcome measures: number of detected malignant melanomas (MM) and/or atypical MN; quantity, quality, and differences in morphological changes between 'low-risk' patients (no MM in history and < 50 MN) and 'high-risk' patients (MM in history and/or > 50 MN). Compliance: the number of patients who joined a recommended follow-up scheme.

RESULTS

No MM was found in 145 consecutive patients (mean age 28 years, 54% female) during a 4-year period (median follow-up per patient: 24 months; ranging 4-45; at least three visits). In five patients (3%), seven histologically proven atypical MN were shown on whole body examination at sites other than those documented. A total of 1968 images in 177 'low-risk' and 95 'high-risk' MN were analysed: 37% (n = 65) of 'low-risk' and 32% (n = 30) of 'high-risk' MN showed dermoscopic changes (difference not statistically significant), none were suspicious for MM. Compliance, evaluated within a separate database of 303 consecutive patients (mean age 32 years, 52% female) over a 6-month period, was only 46%, although recall letters were used.

CONCLUSIONS

(i) In our setting of daily routines in dermatological private practices long-term follow-up of a single MN seems not to be helpful for the detection of MM. (ii) A whole body examination must be done at each visit. (iii) The clinician's experience of the type and number of possible morphological changes in MN is crucial in order to avoid unnecessary excisions. (iv) The patient's compliance might be an important problem. (v) Cost-effectiveness has yet to be analysed.