Number Of Naevi Research Articles

Low risk of melanoma in patients with atopic dermatitis

There is a possible association between atopy and cancer based on the concept of atopic diseases as a hyper-reactive state of the immune system. Melanoma is an immunogenic tumour, and since patients with atopic dermatitis (AD) are subjected to local and systemic immunosuppressives, it would be expected to find an influence of AD on the melanoma risk. There is a positive correlation between the number of naevi and melanoma risk, and children and adults with AD have fewer naevi than controls although many patients receive ultraviolet treatment. This study aims to investigate the melanoma risk in a retrospective cohort of AD patients compared with the population. 6280 AD patients born 1935-1979 visited five Dermatology clinics during 1986-2004. Mean follow-up time was 36.7 years (SD 6.9) corresponding to 230 742 person-years at risk. The cohort file was linked to the National Cancer register. Six AD patients with melanoma were identified, and the Poisson regression analysis adjusted for age group, sex and year resulted in an incidence rate ratio of 0.49 (95% confidence interval: 0.27-1.35, P = 0.08) for the AD group compared with the total population in the region. A low risk to develop melanoma was found in AD patients. However, the results must be interpreted with caution since the small number of expected cases of melanoma makes the risk estimate sensitive to chance effects. We hypothesize that formation of naevi and progression to melanoma is counteracted by the inflammatory process in the skin of AD patients.

The prevalence of melanocytic naevi among schoolchildren in South Hungary

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. 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. 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. 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. 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.

Dysplastic naevi with moderate to severe histological dysplasia: a risk factor for melanoma

The risk of malignant melanoma associated with histologically dysplastic naevi (HDN) has not been defined. While clinically atypical naevi appear to confer an independent risk of melanoma, no study has evaluated the extent to which HDN are predictive of melanoma. To estimate the risk of melanoma associated with HDN. Secondarily, the risk associated with number of naevi and large naevi is estimated. We enrolled 80 patients with newly diagnosed melanoma along with 80 spousal controls. After obtaining information on melanoma risk factors and performing a complete cutaneous examination, the most clinically atypical naevus was biopsied in both cases and controls. Histological dysplasia was then assessed independently by 13 dermatopathologists (0, no dysplasia; 1, mild dysplasia; 2, moderate dysplasia; 3, severe dysplasia). The dermatopathologists were blinded as to whether the naevi were from melanoma subjects or controls. Multivariate analyses were performed to determine if there was an independent association between the degree of histological dysplasia in naevi and a personal history of melanoma. In persons with naevi receiving an average score of > 1 (i.e. naevi considered to have greater than mild histological dysplasia), there was an increased risk of melanoma [odds ratio (OR) 2.60, 95% confidence interval (CI) 0.99-6.86] which persisted after adjustment for confounders (OR 3.99, 95% CI 1.02-15.71). Very few dermatopathologists reliably graded naevi of subjects with melanoma as being more dysplastic than naevi of control subjects. Among the entire group, the interobserver reliability associated with grading histological dysplasia in naevi was poor (weighted kappa 0.28). HDN do appear to confer an independent risk of melanoma. However, this result may add more to our biological understanding of melanoma risk than to clinical assessment of risk, because HDN assessed by a single pathologist generally cannot be used to assess risk of melanoma. Future studies should be directed at establishing reproducible, predictive criteria for grading naevi.

Multiple senile lentigos of the face, a skin ageing pattern resulting from a life excess of intermittent sun exposure in dark-skinned caucasians: a case-control study

Different patterns of skin ageing can be described depending on the predominant lesions, i.e. wrinkles, laxity, atrophy, senile lentigos (SLs), etc. They may correspond to different epidemiological contexts. To identify and assess the epidemiological factors for a skin ageing pattern characterized by a high density of SLs on the face, or 'lentigo ageing pattern' (LAP). An age- and sex-matched case-control study was conducted in individuals aged between 60 and 80 years, comparing cases (n = 118) with a very high number of SLs on the face for their age, and controls (n = 118) with no or very few SLs for their age. The cases and controls were recruited in two hospitals. In univariate and multivariate analysis, LAP was associated with skin types III and IV, with frequent sunburns, and with the part of the lifetime cumulative sun exposure which was received during vacations. Conversely, there was no link with the occupational and everyday exposures and the total cumulative exposure. LAP was associated with multiple solar lentigos of the upper back. No relationship was found with postmenopausal hormonal therapy, number of naevi, or freckles. Different epidemiological factors may account for the different skin ageing patterns. LAP seems to develop preferentially in dark-skinned caucasians who have repeatedly received intermittent and intense sun irradiations throughout their life, and have often developed solar lentigos on the upper back earlier in life, whereas the 'prominent wrinkling' pattern is known to affect light-skinned people and smokers with a life excess of continuous exposure.

A New Approach in the Determination of Eumelanin in Human Hair Using near Infrared Spectroscopy

Page 10 NIR news Vol. 16 No. 6 (2005) The aetiology of skin cancers is a complex interaction between genetic characteristics (phenotypically expressed by skin complexion) and exposure to sun. These two factors, complexion and exposure to sun, modulate the risk of different tumours in a different way. In detail, for melanoma, risk is associated with fair complexion (light blonde or red hair, high number of naevi and freckles, tendency to sunburn) and with intense and intermittent exposures like those experienced during holidays. Risk profiles are defined by semi-quantitative empiric parameters (scale of hair, eye and skin colour, acute reactivity scale, such as MED, Minimal Erithemal Dose) for the tendency to sunburn. Knowledge of the biochemistry of skin pigments, the melanins, has made it possible to identify a biological marker. Melanins are biopolymers present in the hair and epidermis. There are two distinct types of melanin pigments: the eumelanins, efficient in photo-protection and responsible for black and brown colour and the pheomelanins, bad at photo-protection and responsible for yellow and reddish colour. Most Caucasian populations have intermediate skin and hair colour and present these two kind of pigment in different ratios. This study about the distribution of melanin pigment in the population in general and in groups of subjects with different cutaneous tumours is an original work, starting from results obtained in the biochemical field. The turning point from empirical characterisation to biochemical characterisation of phenotypes by the quantitative determination of melanins in human hair can lead to the selection of groups with an elevated risk of cutaneous tumours. In these groups of people it will be possible to carry out more thorough diagnostic tests (dermatological inspection of skin). A multicentric case-control study was carried out in different European countries. Three groups of about 300 cases were recruited for each cutaneous cancer (cutaneous melanoma, squamous cell carcinoma and basal cell carcinoma) and 300 controls. For each group of people, in addition to data concerning phenotype and sun exposure Eumelanin in Human Hair

Public awareness about risk factors could pose problems for case-control studies: The example of sunbed use and cutaneous melanoma

In a large case-control study we found no association between sunbed use and melanoma risk, but indications for potential recall and recruitment biases made the interpretation of the results difficult. Associations with skin phototype (adj OR for skin type I vs. IV: (2.6, 95% CI 1.5–4.8)), hair colour (adj OR red/blond vs. brown/black 2.0 (95% CI 1.4–2.8)) and number of naevi on both arms (OR > 10 vs. ⩽10 3.13 (95% CI: 2.47; 3.97)) were comparable to previous studies, but negative associations were found between sun exposure and melanoma risk (adj. OR 0.87 (95% CI: 0.65–1.18)) and in cases between sun exposure and naevus count. These observations led us to speculate that cases may have underreported their sun exposure and, most likely, their sunbed exposure. High percentages of sunbed use among controls indicated possible recruitment bias: eligible controls who were sunbed users were probably more likely to accept the invitation to participate than non-users, possibly due to a feeling of ‘guilt’ or ‘worry’ about their habits. Such selective participation may have strongly influenced the risk estimates of sunbed use in our study.

A multicentre epidemiological study on sunbed use and cutaneous melanoma in Europe

A large European case–control study investigated the association between sunbed use and cutaneous melanoma in an adult population aged between 18 and 49 years. Between 1999 and 2001 sun and sunbed exposure was recorded in 597 newly diagnosed melanoma cases and 622 controls in Belgium, France, The Netherlands, Sweden and the UK. Fifty three precent of cases and 57% of controls ever used sunbeds. The overall adjusted odds ratio (OR) associated with ever sunbed use was 0.90 (95% CI: 0.71–1.14). There was a South-to-North gradient with high prevalence of sunbed exposure in Northern Europe and lower prevalence in the South (prevalence of use in France 20%, OR: 1.19 (0.68–2.07) compared to Sweden, prevalence 83%, relative risk 0.62 (0.26–1.46)). Dose and lag-time between first exposure to sunbeds and time of study were not associated with melanoma risk, neither were sunbathing and sunburns (adjusted OR for mean number of weeks spent in sunny climates >14 years: 1.12 (0.88–1.43); adjusted OR for any sunburn >14 years: 1.16 (0.9–1.45)). Host factors such as numbers of naevi and skin type were the strongest risk indicators for melanoma. Public health campaigns have improved knowledge regarding risk of UV-radiation for skin cancers and this may have led to recall and selection biases in both cases and controls in this study. Sunbed exposure has become increasingly prevalent over the last 20 years, especially in Northern Europe but the full impact of this exposure on skin cancers may not become apparent for many years.

Risk of melanoma and vitamin A, coffee and alcohol: a case–control study from Italy

Limited information is available on the association between the risk of cutaneous malignant melanoma (CMM) and dietary factors. The issue was investigated using data from a case-control study conducted in Italy between 1992 and 1994, including 542 patients with incident, histologically confirmed CMM and 538 controls, admitted to the same hospitals as cases for non-dermatologic and non-neoplastic diseases. We found a significant inverse association between vitamin A intake and CMM risk. The multivariate odds ratio, after allowance for phenotypic characteristics and history of sunburns, for the highest, compared with the lowest, quartile of intake was 0.71 (95% confidence interval (CI) 0.50-1.02) for beta-carotene, 0.57 (95% CI 0.39-0.83) for retinol, and 0.51 (95% CI 0.35-0.74) for total vitamin A. We found no appreciable association of CMM risk with selected food items, including fish, meat, vegetables, fruit, dairy products, wholemeal bread, alcohol, coffee and tea drinking. Consumption of tea appeared to have a protective effect on CMM risk. The relations with measures of dietary vitamin A are, however, moderate compared with the associations between phenotypic characteristics, sun exposure and number of naevi and CMM risk.

Meta-analysis of risk factors for cutaneous melanoma: I. Common and atypical naevi

A systematic meta-analysis of observational studies of melanoma and one of the most important risk factors, the number of naevi, was conducted in order to clarify aspects of the aetiology of this disease. Following a systematic literature search, relative risks (RRs) were extracted from 46 studies published before September 2002. Dose–response random effects models were used to obtain pooled estimates. Sub-group analysis and meta-regression were carried out to explore sources of between-study variation and bias. Sensitivity analyses investigated the reliability of the results and any publication bias. Number of common naevi was confirmed an important risk factor with a substantially increased risk associated with the presence of 101–120 naevi compared with <15 (pooled Relative Risk (RR) = 6.89; 95% Confidential Interval (CI): 4.63, 10.25) as was the number of atypical naevi (RR = 6.36 95%; CI: 3.80, 10.33; for 5 versus 0). The type of study and source of cases and controls were two study characteristics that significantly influenced the estimates. Case-control studies, in particular when the hospital was the source for cases or controls, appeared to present much lower and more precise estimates than cohort studies.

Risk factors for cutaneous malignant melanoma among aircrews and a random sample of the population

Aims: To evaluate whether a difference in the prevalence of risk factors for malignant melanoma in a random sample of the population and among pilots and cabin attendants could explain...

Validity of an unsupervised self-administered questionnaire for self-assessment of melanoma risk.

Mass screening for cutaneous melanoma is impracticable because of its low yield and high costs. The validity of self-selection of high-risk individuals through self-assessment of melanoma risk factors is not known. The aim of this study was to assess the validity of an unsupervised self-administered questionnaire for the self-assessment of melanoma risk. In a case-control study, melanoma cases (n = 202) and controls (n = 202) matched for age and gender filled in a questionnaire about melanoma risk factors. After filling in the questionnaire, all participants were interviewed and examined by a dermatologist in order to compare self-assessment with physician-assessment. The number of naevi, skin phototype and ultraviolet damage to the skin were identified as independent risk factors for melanoma on both self-assessment and physician-assessment. Receiver operating characteristics analysis showed no statistically significant difference between the accuracy of the self-assessment-based model and the model based on physician-assessment. While excluding 90% of the controls, the self-assessment-based high-risk group included 39% (95% confidence interval 31-48%) of the melanoma patients and the physician-assessment-based high-risk group included 42% (95% confidence interval 33-52%) of the melanoma patients. In conclusion, an unsupervised self-administered questionnaire is, to some extent, useful for the identification of individuals at high risk for melanoma. The moderate accuracy of self-assessment and physician-assessment to identify individuals at high risk for melanoma is a limitation for the practicability of targeted melanoma screening in general.

Development of an integrated method of skin phenotype measurement using the melanins

Different types of melanin pigments have recently been identified and recognized as critical determinants of the photosensitivity of individuals. Eumelanin, the black to brown melanin pigments, are believed to protect against ultraviolet-induced cell damage, while phaeomelanin, the reddish brown variant, is thought to be photosensitizing. The relative, qualitative and absolute amount of melanin production under stimulation of solar radiation is likely to be genetically determined. The hypothesis of this study is that determination of these values can help in identifying those people who are less protected. However, these techniques must be evaluated at a population level and against traditional epidemiological measures. We assessed the amount and type of melanin in 195 subjects in four centres across Europe, relating the results to epidemiological measures such as skin characteristics, history of sunburns and number of naevi. The most important finding was that eumelanin and phaeomelanin have very different distributions in the population, being associated with other phenotype characteristics with different patterns. The relationship between phaeomelanin and eumelanin is linearly inverse in the range from black to dark blonde hair colour, while it is weakly directly proportional in the range from dark blonde to light blonde, with people with red hair showing a peculiar pattern. Phaeomelanin rather than eumelanin seemed to be independent of other skin characteristics. The results show the feasibility of a further study with an appropriate case-control design and accurate determination of melanin.

Do larger people have more naevi? Naevus frequency versus naevus density.

It is unclear which of the number or the density of naevi on the skin is the more appropriate measure of risk of melanoma. Furthermore, the relationship between the number of naevi and their density in an individual has not been explored. Thus, for example, it is unknown if larger people tend to have more naevi by virtue of having a larger skin area, or if the density of naevi is similar in people of different body sizes. In this study, we explored the relationship between the number and the density of naevi in a sample of adolescents. A sample survey of naevi in 472 grade 9 secondary school students (aged 14-15 years) was conducted in Tasmania, Australia during 1992, and a subset of these individuals was followed up in 1997. Counts of naevi of various sizes were taken on the arm, leg, and back. Naevus density was estimated by using an algorithm to estimate body surface area from the height and weight of an individual. More general relationships of the naevus counts to height and weight were also explored. Finally, we considered whether the relationship between naevus density and the anthropometric variables could be confounded by exposure to ultraviolet radiation. The mean number of naevi was very similar in the two samples. Naevus density was slightly lower in the 1997 sample, mainly because of increasing body size in the cohort. The numbers of naevi were only weakly related to height and weight in males, and there was essentially no relationship in females. Regression analysis showed significant relationships of weight to the back naevus counts in males in 1992 and 1997, and to the arm naevus count in males in 1997; otherwise, none of the regression coefficients for height and weight were statistically significant. This picture did not change following adjustment for potentially confounding variables indicating time spent outdoors or in the sun. Furthermore, there was no evidence that time spent in the sun was related to the body mass index. It appears that the number and density of naevi in an individual are unrelated. Accordingly, with the present state of knowledge concerning the risk of melanoma, both the number and density of naevi should be considered as equally valid in future studies as markers of the risk of melanoma, and in studies on the natural history of naevi. If the disease mechanism is systemic, and not related to particular naevi, naevus density might form the better marker of risk. However, if the disease mechanism is related to effects on particular naevi, then the risk would vary in proportion to the number of naevi.

Sunscreens and cutaneous malignant melanoma: an Italian case-control study.

The possible relation between use of sunscreens and the risk of cutaneous malignant melanoma (CMM) was investigated in a case-control study conducted in 27 Italian centres on 542 incident, histologically confirmed cases and 538 controls admitted for acute, other than neoplastic or dermatologic conditions. Compared with subjects reporting never sunscreen use, the multivariate odds ratios (OR), after allowance for age, sex, geographic area, education, skin, eye and hair colour, freckles, number of naevi, history of sunburns, tanning pattern and duration of sunny vacations, were 0.97 (95% confidence interval [CI] 0.69 to 1.35) for those reporting "sometimes" and 0.80 (95% CI 0.54 to 1.17) for those reporting "often " sunscreen use. With reference to type of product most frequently used, the ORs were 0.96 (95% CI 0.52 to 1.77) for minimal, 0.90 (95% CI 0.63 to 1.28) for moderate and 1.41 (95% CI 0.85 to 2. 35) for high sunburn protection factor. With reference to duration of use, the OR was 0.86 (95% CI 0.58 to 1.29) for use started since >/=20 years. None of the corresponding trends in risks were significant. The ORs for sunscreen use were similar across strata of major identified covariates and, if anything, tended to decline after multivariate analysis. The present findings confirm that sunscreen use, as currently adopted in Italy, is not appreciably related to subsequent CMM risk.

Cutaneous malignant melanoma and sun exposure in Spain.

Cutaneous malignant melanoma has an increasing importance all over the world. However very few epidemiological studies have been published from Spain, and Spanish people have not become aware of the problem. This study was designed to examine sun exposure patterns and other related items among 116 consecutive patients with melanoma and 235 controls. Each subject answered a questionnaire covering the place of residence, sun exposure details and other risk factors, and underwent a skin examination. Continuous sun exposure due to residence or occupation was associated with an odds ratio (OR) of 2.0 (95% confidence interval [CI] = 1.2-3.3). People who lived in the city but spent 50% of their time in rural areas for holidays had an OR of 2.2 (95% CI = 1.3-3.8) when compared with those living in urban and rural areas. The OR for people who sunbathed more than 30 times a year was 1.8 (95% CI = 1.2-2.8), and outdoor leisure time was also associated with melanoma appearance when exposure was greater than 60 units in the last 2 years, with an OR of 3.0 (95% CI = 1.6-5.5); 1 unit is equivalent to total body sun exposure for at least 2 h. These OR estimates were adjusted for age, skin type and the number of naevi. Construction workers (OR = 1.6; 95% CI = 0.5-5.6) had increased risk after adjustment for skin type, age and freckle count (OR = 4.3; 95% CI = 1.8 9.9) or mole count (OR = 2.8; 95% CI = 1.4-5.8). Working as a farmer was a protective factor after adjustment (OR = 0.5; 95% CI = 0.3-0.8). The use of sunscreens was a protective factor against melanoma (OR = 2.6; 95% CI = 1.6-3.6 for non-users). Campaigns should focus on advising people to avoid sun exposure in sunny places and to use sunscreens every time they are exposed to the sun.

Instrumental measurement of skin colour and skin type as risk factors for melanoma: a statistical classification procedure.

A statistical procedure to evaluate melanoma risk in Caucasian subjects on the basis of colorimetric measurement of skin colour and Fitzpatrick phototype is described. One hundred and sixty melanoma patients and 546 randomized healthy subjects of similar age, sex and place of origin were examined in the same period for skin colour using a tristimulus colorimeter and for Fitzpatrick phototype. A clinical score for classification purposes was obtained by statistical discriminant analysis with multivariate data transformation and dimension reduction techniques. A Fisher linear classifier was chosen for its simplicity and robustness in correctly predicting melanoma risk in new subjects. The classification rule was designed to avoid classifying subjects at high risk for melanoma as low risk, i.e. to give a negligible number of false negatives at the expense of more false positives. The procedure is objective and readily adapted to different clinical requirements. This is only a preliminary study but it is hoped that by performing more complex statistical analyses, e.g. neural networks, and adding other parameters (proven risk factors such as number of naevi) the performance will be further improved.

Public awareness of malignant melanoma risk factors in Germany.

STUDY OBJECTIVE: To evaluate the effects of a German public education campaign which aimed to improve knowledge on risk factors for malignant melanoma. DESIGN: Comparison of data from two successive...

A comparative study of atypical and melanocytic naevi on the tropical island Cura??ao and in The Netherlands

A cross-sectional study was undertaken in 270 inhabitants of The Netherlands (moderate maritime climate, latitude 51 degrees 5' N-53 degrees 3' N) with skin types I-III and 757 inhabitants of the tropical island Curaçao (latitude 12 degrees 2' N-12 degrees 23' N). The latter group consisted of 282 White individuals (mostly Dutch immigrants) and 475 people with non-White skin types IV, V and VI. All participants underwent total skin examination and melanocytic naevi (MN) and clinically atypical naevi (AN) were noted. There was no statistical difference in the mean number of naevi > or = 2 mm or > or = 5 mm between the Curaçao and The Netherlands White groups, but the mean number of naevi > or = 2 mm and > or = 5 mm was significantly lower in the Curaçao non-White group. We found no obvious differences in mean naevus counts between genders and the various comparable age groups. Furthermore, we found no significant difference in mean crude and mean age-standardized prevalence of (one or more) AN between Whites in The Netherlands and on Curaçao. The Mantel-Haenszel prevalence ratio weighted for age and gender differences of Curaçao Whites vs non-Whites was 5.93 (95% confidence interval 3.9-12.0), demonstrating that AN are significantly less prevalent in darker skin types. In all groups, people with AN had significantly more MN than people without AN. We found a generation-dependent difference in the expression of AN among White inhabitants of The Netherlands and on Curaçao, with a higher prevalence of AN in the younger generation.

Regional distribution of melanocytic naevi in relation to sun exposure, and site-specific counts predicting total number of naevi.

The role of exposure to ultraviolet light in the formation of melanocytic naevi was analysed by investigating the regional naevus distribution in 310 subjects (30-50 years) from a Swedish census file. The lateral aspect of the arms and the back had the largest concentration of naevi. The mean naevus count per unit surface area was higher in intermittently exposed than in rarely exposed skin (p less than 0.001), while the lowest mean count was found in chronically exposed skin. These results support the idea that intermittent exposure to ultraviolet light has a "naevogenic" effect while chronic exposure might be protective. Dysplastic naevi had a distribution pattern quite different from common naevi. Considering the distribution pattern solely, dysplastic naevi seem to develop independently of exposure to ultraviolet light. The numbers of naevi in different skin areas were tested for their power in predicting the total body naevus count. The strongest correlations were found between total counts and counts on the anterior surface of the thighs and the lateral aspect of the arms. Counts from any of these areas will provide a practical and satisfactory estimate of the total number of naevi.

Genetic susceptibility to naevi – a twin study

The risk of malignant melanoma to an individual is strongly related to their total number of benign melanocytic naevi. To investigate the possibility that numbers of naevi may have an inherited basis, naevi were examined in 23 monozygotic and 22 dizygotic twin pairs. A strong correlation in total numbers of naevi 3 mm or more in diameter was observed between MZ twins (intraclass correlation 0.83), but there was no significant correlation between DZ twins (correlation -0.24). There was no increased concordance in presence of naevi 5 mm or more over that expected by chance, for MZ or DZ twins. The results suggest a strong inherited basis for total naevus count and hence melanoma risk, perhaps involving a number of interacting genes.