Development and elimination of pigmented moles, and the anatomical distribution of primary malignant melanoma

Nevus-associated Lentigo Maligna and Lentigo Maligna Melanoma, Clinicopathological Features

Nevus-associated lentigo maligna and lentigo maligna melanoma (NALMM) are rarely described in the literature and are considered an incidental finding. This study aimed to evaluate the frequency of NALMM and its clinicopathological features. A total of 201 histopathology reports were reviewed and among them 20% of the samples corresponded to NALMM, with females overrepresented in this group (p = 0.02). A significant association was also observed between NALMM with the presence of multiple nevi (p = 0.01), and dysplastic nevi (p = 0.04). Moreover, the risk of developing a second melanoma of nevus-associated type was 4.3 times higher in patients with NALMM. These results indicate that NALMM is more frequent than previously reported, suggesting that the associated nevus could interact or even act as a precursor for LM/LMM. Future studies with larger samples allied to techniques like confocal microscopy and molecular analysis are essential to determine this biological link between nevus and LM/LMM.

Body Site Distribution of Acquired Melanocytic Naevi and Associated Characteristics in the General Population of Caucasian Adults: A Scoping Review

The number of melanocytic naevi is a major risk factor for melanoma. The divergent pathway hypothesis proposes that the propensity for naevus proliferation and malignant transformation may differ by body site and exposure to ultraviolet (UV) radiation. This scoping review aimed to summarise the evidence on the number and distribution of naevi (≥ 2 mm) on the body overall and by individual anatomical sites in Caucasian adults, and to assess whether studies used the International Agency for Research on Cancer (IARC) protocol to guide naevus counting processes. Systematic searches of Embase and PubMed identified 661 potentially relevant studies, and 12 remained eligible after full-text review. Studies varied widely in their counting protocols, reporting of naevus counts overall and by body sites, and used counting personnel with differing qualifications. Only one study used the IARC protocol. Studies reported that the highest number of naevi was on the trunk in males and on the arms in females. Body sites which receive intermittent exposure to UV radiation had higher density of naevi. Larger naevi (≥ 5 mm) were detected mostly on body sites intermittently exposed to UV radiation, and smaller naevi (< 5 mm) on chronically exposed sites. Studies reported that environmental and behavioural aspects related to UV radiation exposure, as well as genetic factors, all impact body site and size distribution of naevi. This review found that to overcome limitations of the current evidence, future studies should use consistent naevus counting protocols. Skin surface imaging could improve the reliability of findings. An updated IARC protocol is required that integrates these emerging standards and technologies to guide reliable and reproducible naevus counting in the future.

Ultraviolet radiation and cutaneous melanoma: a historical perspective

In this article, we summarize the research that eventually led to the classification of the full ultraviolet (UV) radiation spectrum as carcinogenic to humans. We recall the pioneering works that led to the formulation of novel hypotheses on the reasons underlying the increasing burden of melanoma in light-skinned populations. It took long before having compelling evidence on the association between UV and melanoma, in particular, the importance of UV exposure during childhood for both the occurrence of melanoma and death. The role of UVA was established only after 2005. If molecular lesions caused by UV radiation are better known, the precise mechanism by which UV exposure drives melanoma occurrence and progression still needs to be elucidated. More research on the UV-melanoma relationships has led to more evidence-based sun-protection recommendations, especially for children, and to effective control of the artificial UV tanning fashion. Since around 1985-1995, the mortality because of melanoma has started to decrease in younger age groups in most light-skinned populations. If sun protection among children remain on top of public health agendas, there is a fairly great chance that melanoma mortality will stabilize and steadily decrease in all light-skinned populations. The introduction of effective therapies against metastatic disease will improve this reversal in mortality trends.

Association of Phenotypic Characteristics and UV Radiation Exposure With Risk of Melanoma on Different Body Sites

Importance

Two pathways have been hypothesized for the development of cutaneous melanoma: one typically affects the head and neck, a site with chronic sun damage, and the other affects the trunk, which is less exposed to the sun. However, the possible cause of limb melanomas is less studied under this hypothesis.

Objective

To investigate the association between phenotypic characteristics, pattern of UV radiation exposure, and risk of melanoma on different body sites.

Design, Setting, and Participants

This study used data on 161 540 women with information on phenotypic characteristics and UV radiation exposure who were part of the Norwegian Women and Cancer study, a population-based prospective study established in 1991 with exposure information collected by questionnaires at baseline and every 4 to 6 years during follow-up through 2015. Data analysis was performed from October 2017 through May 2018.

Exposures

Participants reported hair color, eye color, untanned skin color, number of small symmetric and large asymmetric nevi, and freckling, as well as histories of sunburns, sunbathing vacations, and indoor tanning in childhood, adolescence, and adulthood.

Main Outcomes and Measures

The Norwegian Women and Cancer study was linked to the Cancer Registry of Norway for data on cancer diagnosis and date of death or emigration. Primary melanoma site was categorized as head and neck, trunk, upper limbs, and lower limbs.

Results

During follow-up of the 161 540 women in the study (mean age at study entry, 50 years [range, 34-70 years]; mean age at diagnosis, 60 years [range, 34-87 years]), 1374 incident cases of melanoma were diagnosed. Having large asymmetric nevi was a significant risk factor for all sites and was strongest for the lower limbs (relative risk [RR], 3.38; 95% CI, 2.62-4.38) and weakest for the upper limbs (RR, 1.96; 95% CI, 1.22-3.17; P = .02 for heterogeneity). Mean lifetime number of sunbathing vacations was significantly associated with risk of trunk melanomas (RR, 1.14; 95% CI, 1.07-1.22) and lower limb melanomas (RR, 1.12; 95% CI, 1.05-1.19) but not upper limb melanomas (RR, 0.98; 95% CI, 0.88-1.09) and head and neck melanomas (RR, 0.87; 95% CI, 0.73-1.04; P = .006 for heterogeneity). Indoor tanning was associated only with trunk melanomas (RR for the highest tertile, 1.49; 95% CI, 1.16-1.92) and lower limb melanomas (RR for the highest tertile, 1.33; 95% CI, 1.00-1.76; P = .002 for heterogeneity). Skin color, hair color, small symmetric nevi, and history of sunburns were associated with risk of melanoma on all sites.

Conclusions and Relevance

These results appear to support the hypothesis of divergent pathways to melanoma and that recreational sun exposure and indoor tanning are associated with melanoma on the lower limbs, the most common site of melanoma in women. These findings appear to have important preventive implications.

The Influence of Female Hormones on Malignant Melanoma

Several lines of biological evidence have suggested a relationship between the behaviour of melanocytes and cutaneous malignant melanoma (CMM) and the action of female hormones. The present overview, however, indicates that the effect of reproductive, menstrual and hormonal factors, including oral contraceptives, on onset and outcome of CMM must be very weak, if any. The only consistent findings which may suggest a role of female hormones on CMM seem to be: 1) a different distribution by anatomic site in men and women, and 2) a more favorable outcome of CMM in women as compared to men. Neither of them, however, necessarily implies a direct effect of female hormones on CMM.

Sun exposure and skin cancer, and the puzzle of cutaneous melanoma: A perspective on Fears et al. Mathematical models of age and ultraviolet effects on the incidence of skin cancer among whites in the United States. American Journal of Epidemiology 1977; 105: 420-427

Sunlight has been known as an important cause of skin cancer since around the turn of the 20th Century. A 1977 landmark paper of US scientists Fears, Scotto, and Schneiderman advanced a novel hypothesis whereby cutaneous melanoma was primarily caused by intermittent sun exposure (i.e. periodic, brief episodes of exposure to high-intensity ultraviolet radiation) while the keratinocyte cancers, squamous cell carcinoma and basal cell carcinoma, were primarily caused by progressive accumulation of sun exposure. With respect to cutaneous melanoma, this became known as the intermittent exposure hypothesis. The hypothesis stemmed from analysis of measured ambient ultraviolet radiation and age-specific incidence rates of melanoma and keratinocyte cancers collected as an extension to the US Third National Cancer Survey in several US States. In this perspective paper, we put this novel hypothesis into the context of knowledge at the time, and describe subsequent epidemiological and molecular research into melanoma that elaborated the intermittent exposure hypothesis and ultimately replaced it with a dual pathway hypothesis. Our present understanding is of two distinct biological pathways by which cutaneous melanoma might develop; a nevus prone pathway initiated by early sun exposure and promoted by intermittent sun exposure or possibly host factors; and a chronic sun exposure pathway in sun sensitive people who progressively accumulate sun exposure to the sites of future melanomas.

Edward Maxwell (Max) Nicholls (1927-2011), a Key Player in the Development of the Two-Hit Model of Tumor Formation

E. M. Nicholls (1927-2011) was a humanist, medical practitioner, human biologist, geneticist and, above all, a teacher, as well as a husband and father. He believed that he had made a fundamental contribution to the two-hit model of cancer formation. This hypothesis is associated with retinoblastoma, in particular. Nicholls presented it through his observations on neurofibromatosis. He received little credit for what he believed was his most original contribution to medical science. This note attempts to redress the balance in his favor.

Cross-sectional analysis of the dermoscopic patterns and structures of melanocytic naevi on the back and legs of adolescents

BACKGROUND

Junctional (flat) naevi predominate on the extremities, whereas dermal (raised) naevi are found primarily on the head, neck and trunk. Few studies have investigated the anatomical site prevalence of melanocytic naevi categorized using dermoscopy.

OBJECTIVES

To identify the prevalence of dermoscopic patterns and structures of naevi from the back and legs of adolescents.

METHODS

Dermoscopic images of acquired melanocytic naevi were obtained from the back and legs of students from a population-based cohort in Framingham, Massachusetts. Naevi were classified into reticular, globular, homogeneous or complex dermoscopic patterns. Multinomial logistic regression modelling assessed the associations between dermoscopic pattern and anatomical location.

RESULTS

In total 509 participants (mean age 14 years) contributed 2320 back naevi and 637 leg naevi. Compared with homogeneous naevi, globular and complex naevi were more commonly observed on the back than the legs [odds ratio (OR) 29·39, 95% confidence interval (CI) 9·53-90·65, P < 0·001 and OR 6·8, 95% CI 2·7-17·14, P < 0·001, respectively], whereas reticular lesions were less likely to be observed on the back than on the legs (OR 0·67, 95% CI 0·54-0·84, P = 0·001). Naevi containing any globules were more prevalent on the back than on the legs (25% vs. 3·6%, P < 0·001). Naevi containing any network were more prevalent on the legs than on the back (56% vs. 40·6%, P < 0·001).

CONCLUSIONS

These findings add to a robust body of literature suggesting that dermoscopically defined globular and reticular naevi represent biologically distinct naevus subsets that differ in histopathological growth pattern, age- and anatomical-site-related prevalence, molecular phenotype and aetiological pathways.

The incidence and position of melanocytic nevi for the purposes of forensic image comparison

Expert witness opinion based on the comparison of images has been accepted by UK courts as admissible evidence in relation to issues of identity. Within images of the hand are a multiplicity of anatomical features of different aetiology, incidence and distribution patterns and this includes melanocytic nevi, referred to more colloquially as moles and/or birthmarks. The hand is not a common place for these isolated features to develop and so their presence in this anatomical region has the potential to be useful for issues of identity. The results of this study show that approximately 9 % of individuals in a sample of 476 hands, displayed at least one nevus on the back of their hand and, contrary to the literature, the incidence was found to be greater in females (15 % of female cohort) than males (7 % of male cohort). Almost a third of all nevi identified on the dorsum of the hand were abnormal or dysplastic. The most frequent location for these aggregations of melanocytes was in the central region of the dorsum of the hand or at the base of the index finger. The relevance of nevi identified in the image of a perpetrator’s hand and also on that of a suspect/accused is discussed in relation to the issue of whether the images have originated from the same individual.

Tanning and increased nevus development in very-light-skinned children without red hair

OBJECTIVE

To examine the relationship between tanning and nevus development in very-light-skinned children.

DESIGN

Prospective cohort nested within a randomized controlled trial. Skin examinations in 3 consecutive years (2004, 2005, and 2006) included full-body counts of nevi, skin color and tanning measurement using colorimetry, and hair and eye color evaluation by comparison with charts. Telephone interviews of parents provided sun exposure, sun protection, and sunburn history.

SETTING

Large managed-care organization and private pediatric offices in the Denver, Colorado, metropolitan area.

PARTICIPANTS

A total of 131 very-light-skinned white children without red hair and 444 darker-skinned white children without red hair born in Colorado in 1998.

MAIN OUTCOME MEASURES

Full-body nevus counts at ages 6 to 8 years.

RESULTS

Among very-light-skinned white children, geometric mean numbers of nevi for minimally tanned children were 14.8 at age 6 years; 18.8 at age 7 years; and 22.3 at age 8 years. Mean numbers of nevi for tanned children were 21.2 at age 6 years; 27.9 at age 7 years; and 31.9 at age 8 years. Differences in nevus counts between untanned and tanned children were statistically significant at all ages (P < .05 for all comparisons). The relationship between tanning and number of nevi was independent of the child's hair and eye color, parent-reported sun exposure, and skin phototype. Among darker-skinned white children, there was no relationship between tanning and nevi.

CONCLUSIONS

Very-light-skinned children who tan (based on objective measurement) develop more nevi than children who do not tan. These results suggest that light-skinned children who develop tans may be increasing their risk for developing melanoma later in life.

Melasma and its association with different types of nevi in women: a case-control study

Background

Very little is known about possible association of nevi and melasma. The study objective was to determine if there is an association between melasma and existence of different kinds of nevi.

Methods

In a case-control study, 120 female melasma patients referred to dermatology clinic of Ardabil and 120 patients referred to other specialty clinics who lacked melasma were enrolled after matching for age. Number of different types of nevi including lentigines and melanocytic nevi were compared between case and control group patients. Data were entered into the computer and analyzed by SPSS 13 statistical software.

Results

Mean number of lentigines was 25.5 in melasma group compared to 8 in control group(P < 0.01). Mean number of melanocytic nevi was 13.2 in cases compared to 2.8 in control group(P < 0.001). Multivariate analysis showed that existence of freckles, lentigines and more than three melanocytic nevi were positively related to developing melasma. The chance of melasma increased up to 23 times for patients having more than three melanocytic nevi. Congenital nevi were observed among 10% both in case and control groups. Campbell de morgan angiomas were seen among 26 patients(21.8%) in case group compared to 6 patients(5%) in control group.

Conclusion

Existence of lentigines and melanocytic nevi increases chance of having melasma

Melanocytic nevi in 2783 children and adolescents in Turkey

This study investigated the numbers of melanocytic nevi in Turkish children and adolescents. The research was conducted on 2783 subjects (age range, 7-14 yrs) at three elementary schools in Malatya, Turkey (latitude 38 degrees N). Numbers of melanocytic nevi per subject were counted using a standard international protocol. Comparisons were made with subjects categorized according to age, sex and skin type. The mean melanocytic nevus count was 1.07 +/- 2.37. A significant positive correlation was found between nevus count and age (p < 0.001). The mean count for boys was significantly higher than that for girls (p < 0.001). Subjects with skin type II had a higher mean melanocytic nevus count than the other three groups. This is the first study related to numbers of melanocytic nevi in Turkey. The findings reveal that Turkish children and adolescents have few melanocytic nevi compared to those elsewhere in the world. In line with previous reports on other populations, analysis showed that older age, skin type II, and male sex are associated with higher melanocytic nevus counts. The results underline the importance of ethnic background in melanocytic nevus development.

The Epidemiology of Nevi and Signs of Skin Aging in the Adult General Population: Results of the KORA-Survey 2000

Nevi can approximate the melanoma risk and demographic changes will increase the meaning of signs of skin aging (SSA). However, little is known about the epidemiology of nevi and SSA in the general adult population. We aimed to estimate the prevalence and age distribution of common and atypical nevi and SSA as well as gender differences in a large population-based sample. Within the Cooperative Health Research in the Augsburg Region (KORA) in Germany, a population-based survey was performed. Data were gathered by interview and the number of pigmented lesions and presence of SSA were obtained by dermatological examination. A total of 2,823 adults (mean age 49 years, 50% women) participated (response 67%). Most subjects (60.3%) exhibited 11 to 50 common nevi and 5.2% had at least one atypical nevus. 51.9% were diagnosed with elastosis (Cutis rhomboidalis nuchae, 18.3%; Morbus Favre Racouchot 1.4%). Ephelides were seen in 16%, lentigines solaris in 62.4%, and lentigines seniles in 33.2%. All signs of skin aging increased significantly with age and so did lentigines solaris, seniles, and actinic keratoses. In contrast, common and atypical nevi and ephelides decreased significantly with age. Signs of skin aging are frequent and increase, in contrast to common and atypical nevi, with age.

Longitudinal assessment of the nevus phenotype in a melanoma kindred

Phenotypic characteristics of members of a melanoma prone kindred with a V126D CDKN2A gene mutation were monitored over approximately 15 y. Thirty-eight previously studied subjects were recruited. Participants underwent a complete skin examination by the same dermatologist who examined them initially. The size and location of all nevi were recorded on a body map diagram. Total nevus number (TNN) and total nevus density (TND) were determined. CDKN2A sequencing verified 13 mutation carriers and 16 non-carriers. Nine participants were spouse controls without a history of melanoma and did not carry a CDKN2A mutation. Mutation carriers demonstrated a greater mean TNN and TND at initial and follow-up examinations compared with non-carriers and continued to develop nevi rather than show nevus regression seen in non-carriers and spouse controls. Non-carriers showed an intermediate nevus phenotype between mutation carriers and spouse controls. Four of the 13 mutation carriers and one non-carrier have developed invasive melanoma. Over a 15-y interval, TNN and TND were increased in mutation carriers compared with non-carriers and spouse controls. Continued accumulation of nevi in mutation carriers supports a nevogenic role for this CDKN2A mutation. An intermediate nevus phenotype in non-carrier family members suggests the presence of additional modifier genes.

Characteristics of Lisch nodules in patients with neurofibromatosis type 1

PURPOSE

To assess the prevalence and location of Lisch nodules among patients with neurofibromatosis type 1.

PATIENTS AND METHODS

This was a prospective observational case series in which 369 consecutive patients from a neurofibromatosis clinic participated. Predetermined inclusion and exclusion criteria were applied to these participants. The presence of Lisch nodules was determined by one of the authors (SMC). The percentage of patients with neurofibromatosis type 1 with Lisch nodules was calculated. Lisch nodules were characterized as being distributed superiorly, inferiorly, or equally in each eye. The percentage of eyes in each group was ascertained.

RESULTS

Among patients of all ages with neurofibromatosis type 1, 63.2% had Lisch nodules, whereas 92% of postpubertal patients had Lisch nodules. Among eyes with Lisch nodules, 80% had an inferior distribution.

CONCLUSIONS

This study corroborated previously reported data regarding the prevalence of Lisch nodules in patients with neurofibromatosis type 1 and found that Lisch nodules were predominantly located inferiorly on the iris. The authors propose that exposure to sunlight may be the mechanism for this distribution of hamartomatous nodules.

Effect of a school-based sun-protection intervention on the development of melanocytic nevi in children

"Kidskin" was a 5-year (1995-1999), school-based intervention trial among first-grade children in Perth, Western Australia. It aimed to assess whether a sun-protection intervention could protect against nevus development on the trunk, face, and arms. Included were a control group, a "moderate intervention" group, and a "high intervention" group. Control schools taught the standard health curriculum, while intervention schools received a specially designed sun-protection curriculum over 4 years. The high intervention group also received program materials over summer vacations when sun exposure was likely to be highest and were offered low-cost sun-protective swimwear. After adjustment for baseline nevus counts and potential confounding, nevus counts on all body sites were slightly lower in both intervention groups relative to the control group at follow-up, although the differences were not statistically significant and the high intervention was no more protective. Children in the moderate and high intervention groups, respectively, had fewer nevi on the back (6%, 95% confidence interval (CI): 0, 12; 4%, 95% CI: -3, 11), chest (boys) (5%, 95% CI: -4, 13; 3%, 95% CI: -8, 14), face (11%, 95% CI: 0, 21; 9%, 95% CI: -6, 21), and arms (8%, 95% CI: -1, 17; 3%, 95% CI: -10, 14).

DNA repair, dysplastic nevi, and sunlight sensitivity in the development of cutaneous malignant melanoma

BACKGROUND

Exposure to UV radiation is associated with cutaneous malignant melanoma (CMM). In mammalian cells, UV radiation induces DNA damage that can be repaired by the nucleotide excision repair system. We designed this case-control study to determine whether DNA repair capacity (DRC) is associated with the risk of CMM and to identify risk factors that may interact biologically with DRC in the development of melanoma.

METHODS

Global DRC was measured in lymphocytes with the host-cell reactivation assay. Data were analyzed by use of multiple regression models. All statistical tests were two-sided.

RESULTS

DRC could be determined for 132 case patients with incident melanoma and for 145 age- and sex-matched control subjects. No statistically significant association between melanoma risk and DRC by itself was found (odds ratio [OR] = 1.0; 95% confidence interval [CI] = 0.6 to 1.7, adjusted for age, sex, lymphocyte viability, and sample storage time). DRC, however, strongly influenced CMM risk in individuals with a low tanning ability or dysplastic nevi. Individuals with a low tanning ability and a low DRC had a higher risk for CMM (OR = 8.6; 95% CI = 2.7 to 27.5) than individuals with a higher tanning ability and a high DRC. Likewise, individuals with dysplastic nevi and a low DRC had a higher relative risk (OR = 6.7; 95% CI = 2.4 to 18.6) than those lacking dysplastic nevi and having a high DRC. Subjects with dysplastic nevi and a high DRC had an intermediate risk. A likelihood-ratio test gave statistically significant interactions between DRC and tanning response (P =.001) and between DRC and dysplastic nevus status (P =.04), which were independently associated with CMM risk.

CONCLUSIONS

DRC may modify the risk for melanoma in the presence of other strong risk factors, such as a low tanning ability and the presence of dysplastic nevi. The occurrence of melanoma in subjects without these risk factors appears to be independent of DRC.

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

BACKGROUND

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.

SUBJECTS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Sex differences in the anatomical distribution of melanocytic nevi in Canadian Hutterite children

BACKGROUND

Studies of the distribution of melanocytic nevi (MN) and/or cutaneous malignant melanoma (CMM) in white populations have commonly observed greater numbers of MN and CMM on the torsos of males and on the limbs of females. The most commonly cited explanation for this sex difference is differential sunlight exposure of body subsites due to gender differences in clothing styles and recreational activities. Less common, but more speculative, explanations suggest hormonal differences or regional differences in melanocytes across body subsites.

OBJECTIVE

The purpose of the present study was to evaluate these explanations in light of sex differences in the anatomical distribution of nevi in Canadian Hutterite children whose traditional religious costume protects them from sun exposure.

METHODS

Nevi counts from 178 male and 154 female children, aged 5 to 15 years, from 23 Central Alberta Hutterite colonies were broken down by age and body subsite.

RESULTS

At age levels from 6 to 15 years, males had greater nevus counts on the torso, whereas females had greater counts on the upper and lower limbs.

CONCLUSION

The appearance of this distribution of nevi in sun-protected children as early as age 6 is problematic for explanations based on differential sunlight exposure and hormonal changes at puberty.

The association between naevi and melanoma in populations with different levels of sun exposure: a joint case-control study of melanoma in the UK and Australia

Two case-control studies were set up to investigate the relationship between melanocytic naevi and risk of melanoma and to compare the naevus phenotype in two countries exposed to greatly different levels of sun exposure and different melanoma rates. In England 117 melanoma cases and 163 controls were recruited from the North-East Thames Region and 183 melanoma cases and 162 controls from New South Wales, Australia. Each subject underwent a whole-body naevus count performed by the same examiner in each country. Relative risks associated with melanocytic naevi in each country were calculated with comparison of naevus data in controls between Australia and England. Atypical naevi were strong risk factors for melanoma in both countries: the odds ratio (OR) for three or more atypical naevi was 4.6 (95% CI 2.0-10.7) in Australia compared with 51.7 (95% CI 6.5-408.4) in England. Common naevi were also significant risk factors in Australia and England with similar odds ratios in the two countries. Prevalence of atypical naevi was greater in Australian controls than in English controls: OR 9.7 (95% CI 1.2-81.7) for three or more atypical naevi in Australia compared with England. For young age groups, the median number of common naevi was greater in Australia than in the UK, whereas for older individuals this difference in naevi number between the two countries disappeared. The prevalence of naevi on non-sun-exposed sites in controls was not significantly different between the two countries. The atypical mole syndrome (AMS) phenotype was more prevalent in Australian controls (6%) than in English controls (2%). The results of this study support the role of sun exposure in the induction of atypical naevi in adults. There was a trend towards stronger risk factors associated with atypical naevi in England compared with Australia. The atypical mole syndrome, usually associated with a genetic susceptibility to melanoma, was more common in Australia than in England, suggesting genetic environmental interactions with the possibility of phenocopies induced by sunlight.

Teaching children about skin cancer: the draw-and-write technique as an evaluation tool

Childhood exposure to sunlight is a risk factor for melanoma. To formulate a meaningful program to educate children about the ill effects of the sun, their extant knowledge base must be determined. We have used the "draw-and-write" technique to assess children's perceptions about the sun, suntans, and skin cancer. A total of 693 school children aged 4 to 13 years were asked to draw pictures and label them in response to a series of carefully worded questions. Awareness of the need to apply sunscreen increased from 44% in children aged 4 to 6 years to 95% in children aged 9 to 10 years. Ten percent of children aged 4 to 6 years already perceived a suntan as attractive. While almost all children were aware of the negative immediate effects of sun exposure, namely sunburn, just 30% of American children aged 11 to 13 were aware that sun exposure is a risk for skin cancer. No differences between boys and girls were seen. The "draw-and-write" technique allows assessment of the attitudes and perceptions of children regarding the sun and skin cancer. It also provides valuable information on which to base health education and evaluate its cost-effectiveness.

Self screening for risk of melanoma: validity of self mole counting by patients in a single general practice

OBJECTIVE

To validate self screening by patients of high mole counts, assess the within family association of sun protection behaviour and mole counts, and estimate prevalence of risk factors for melanoma.

SETTING AND SUBJECTS

Systematic sample of families from a single affluent general practice population in Wessex.

DESIGN

Subjects completed a questionnaire about risk factors for melanoma and counted their moles. Subsequently a mole count was done by a general practitioner trained at dermatology clinics.

MAIN OUTCOME MEASURES

Validation of self counts by observer's count. Within family association of sun protection behaviour and mole counts; self reported risk factors.

RESULTS

199/237 subjects (84%) returned the questionnaire; 212/237 (89%) were examined. High counts by patients on the front of the trunk (> 7 moles of > or = 2 mm) were reasonably sensitive (79%), predictive (75%), and specific (97%) of the observer's mole counts (kappa = 0.74), unlike arm or total body counts. Sun protection behaviour correlated between individuals and other family members (Spearman's coefficient r = 0.50, P < 0.01). In the past three months 15/114 adults (13.2%, 95% confidence interval 7.0% to 19.4%) reported any change in a mole and 6/114 (5.3%, 2.0% to 11.1%) "major" changes; 6/109 adults (5.5%, 2.1% to 11.6%) had both high mole counts and freckling.

CONCLUSIONS

Asking patients to count trunk moles could be a feasible way of identifying patients at high risk of melanoma. Concentrating on reported major changes in moles should avoid considerable workload in general practice. The generalisability of these findings and the adverse effects, net benefit in earlier diagnosis and prevention, and workload implications of such self screening need further research.

Sun exposure and melanocytic naevi in young Australian children

Queensland, Australia, has the highest rates of melanoma in the world and Queensland children have the greatest numbers of melanocytic naevi, the strongest risk factor for melanoma. Although both melanoma and naevi are broadly related to sun exposure in childhood, the relation to individual exposure early in life is difficult to study retrospectively in adults. We surveyed 506 children aged 1-6 years who had been born in Townsville, North Queensland. Sun exposure was assessed by questionnaire and melanocytic naevi were counted using a standard international protocol. Very high counts (upper quarter) of melanocytic naevi were significantly associated with sun exposure of more than 4 hours per day (adjusted relative risk ratio 3.29; 95% Cl 1.12-9.69), and with a history of sunburn (1.89; 1.11-3.21). Melanocytic naevus counts increased with age, light skin reflectance, and freckling. With exposure to intense ultraviolet light in Townsville, children develop melanocytic naevi early in life and in large numbers. We found that both acute and chronic exposure to sun are associated with their development.

Nevus counting as a risk factor for melanoma: comparison of self-count with count by physician

BACKGROUND

The number of total body nevi is a major risk marker for malignant melanoma. No previous study has evaluated the accuracy of whole body large nevus (> or = 5 mm) self-counts.

OBJECTIVE

Our purpose was to evaluate the accuracy of large nevus self-counts by sex, age, educational level, body site, family history of skin cancer, and nevus characteristics.

METHODS

Self-counting of large nevi by 125 patients was compared with physician counting, with attention to nevus characteristics.

RESULTS

Overall, 79% of the self-counts agreed to within +/- 3 nevi of the physician's count. Analysis of variance revealed that the presence of nonpigmented or flat nevi significantly increased the chance of subject undercount, as did male sex.

CONCLUSION

Self-counts of large nevi are comparable to physician's counts and may be useful for melanoma screening.

Complete regression of melanocytic nevi: clues for proper diagnosis

A histopathological study of a distinct papule isolated from a patient's neck is reported and compared to 80 melanocytic nevi. The histogenesis of this unique tumor indicates that it probably represents the residual of a melanocytic nevus in which nevi cells have disappeared but fat infiltration and fibrosis of the dermis and the typical aspects of other cutaneous elements persisted. The finding of focal acantholytic dyskeratosis in multiple foci of the lesion may indicate melanocytic cells regression. Lesions with the histopathological appearance of melanocytic nevi, even in the absence of nevi cells, may be discovered scrutinizing the associated alterations.

Melanocytic nevi in Turner syndrome

One morphologic feature of Turner syndrome is increased numbers of melanocytic nevi; however, little attention has been given to their characterization. The development of a melanoma in one of our patients with Turner syndrome prompted this study. We prospectively examined 10 patients with the disease, confirmed by karyotype. All patients underwent full body skin examination noting the number, size, distribution, and degree of clinical atypia of melanocytic nevi. Representative and unusual lesions were photographed. An average of 115 nevi were seen, with the majority measuring 1 to 5 mm. Most were located on the back and extremities. Clinical atypia was uncommon. Our patients had larger numbers of benign-appearing nevi than the general population. Large numbers of melanocytic nevi is a risk factor for melanoma, suggesting that these patients have an increase in one risk factor. Longitudinal studies are indicated to clarify this issue; nevertheless, we recommend periodic skin examinations and the regular use of sunscreens for individuals with Turner syndrome.

Naevi in schoolchildren in Scotland and Australia

To test the hypothesis that children living in subtropical and tropical environments have more naevi than those of similar ethnicity living in temperature countries, a comparative study of melanocytic naevi in 111 schoolchildren from Brisbane, Australia, and 222 from Glasgow, Scotland, was carried out. All children were aged 13-15 years, of European ancestry, and had spent most of their lives at latitudes of less than 30 degrees S (Australia) or greater than 30 degrees N (Scotland). Using an identical protocol, all naevi of 2 mm or more in diameter occurring on the right arm were counted by either a highly experienced research nurse in Brisbane, or a dermatologist in Glasgow. Hair and eye colour, and facial freckling, were assessed by the examiner, and axillary skin colour of children in both cities was measured using the same reflectance spectrophotometer. Children in Brisbane had significantly more naevi than those in Glasgow (P < 0.05), after adjusting for complexion variables. The difference in the geometric mean number of naevi on the arm was much greater among boys (7.7 vs. 4.4, in Brisbane and Glasgow, respectively) than among girls (7.3 vs. 6.7). This has parallels with the sex differences in melanoma at later ages in the two countries. Besides country of residence, freckles and innate skin colour were the most significant predictors of large numbers of naevi, whereas red hair had a significant protective effect. Overall, these data on prevalence of naevi in children from contrasting environments provide some evidence in support of the theory that naevus development is related to the level of sun exposure in childhood and adolescence.

Sunlight: a major factor associated with the development of melanocytic nevi in Australian schoolchildren

BACKGROUND

Case-control studies have identified melanocytic nevi (MN) as the most important phenotypic risk factor for melanoma. A knowledge of any environmental factors that cause MN may facilitate prevention of melanoma.

OBJECTIVE

This study was undertaken to explore the possible role of ambient solar irradiation in the development of MN in children.

METHODS

With a standard protocol developed after international consultation, the same medical observers examined children in three Australian cities (Melbourne, Sydney, and Townsville) that span a wide range of latitude.

RESULTS

A total of 1123 Australian schoolchildren 6, 9, 12, and 15 years of age were surveyed. Larger numbers of MN were found (mean 65.4 MN, standard deviation 52.9) than in previous studies of children. Prevalence increased with diminishing latitude (51.1 in Melbourne, 66.5 in Sydney and 77.2 in Townsville), particularly in children 6 and 9 years of age. Although nevus numbers were higher in children with light skin and hair, blue eyes, and freckling, the latitude gradient remained after adjustment for these and other factors in multivariate analysis.

CONCLUSION

Latitude of residence, and by implication ambient UV radiation, is strongly related to nevus prevalence in young Australian children. However, these differences diminish with age and may disappear by 15 years of age.

On naevi and melanomas in dysplastic naevus syndrome patients

Cutaneous melanoma may occur as isolated, so-called 'sporadic' cases or in association with multiple atypical naevi and in familial clusters, in which case it is referred to as the familial dysplastic naevus syndrome (DNS). In this retrospective study (a) the number and body distribution of naevocytic naevi and (b) the body distribution of malignant melanoma (MM) in individuals with familial DNS were compared in order to study their association. In 45 patients with familial DNS aged 20-39 years naevus counts on trunk and lower extremities were compared with melanoma data and distributions from a second group of 43 patients from the same DNS families aged 12-66 years. Men had significantly more naevi of a size > or = 2 mm or > or = 5 mm on the back than women (P = 0.02). Women showed a tendency towards a greater number of naevi on the lower extremities than men, but in women no significant difference in naevi between the lower extremities and the back was found. The total number of naevi on the trunk and lower extremities in familial DNS patients was higher than that in the general population. In conclusion, it was found that predilection sites for melanoma in familial DNS patients of both sexes correspond with the distribution of naevi; in males naevi and melanoma counts and percentage distributions were higher on the back, in females both the back and the lower extremities were affected. These findings strongly suggest an association between naevus distribution and melanoma occurrence and site in familial DNS, analogous to earlier reports on sporadic melanoma.

Excess melanocytic nevi in children with renal allografts

BACKGROUND

Renal allograft transplantation is associated with an increased incidence of malignant melanoma. The development of excess melanocytic nevi may be an indicator of this risk.

OBJECTIVE

This study determines the prevalence of melanocytic nevi in children who have received renal allografts.

METHODS

Total and regional melanocytic nevi counts were made in 38 children (27 boys, 11 girls) with a renal allograft and in 38 individually age- and sex-matched healthy controls; counts were related to age, sex, skin type, and duration of immunosuppression.

RESULTS

There was a significant increase in the total number of nevi in the renal transplant group compared with the control group (p < 0.05), with most marked increases occurring on the back and at acral sites. A strong positive correlation between nevi count and duration of immunosuppression independent of age was observed (p < 0.005).

CONCLUSION

Excess numbers of melanocytic nevi occur in children with renal allografts. These patients constitute a risk group for malignant melanoma and require continued assessment.

Influence of cumulative sun exposure on the prevalence of common acquired nevi

BACKGROUND

Conflicting evidence exists on the relation between sun exposure and the number of common acquired nevi. The increase in the number of common acquired nevi until early adulthood and their greater concentration on sun-exposed areas suggested that the growth of common acquired nevi is promoted by UV radiation. Nevertheless, it was noticed that although solar exposure accumulates with age, the number of common acquired nevi decreases after the third decade.

OBJECTIVE

Our purpose was to examine the relation between the prevalence of common acquired nevi and accumulative sun exposure.

METHODS

The number of common acquired nevi on 128 patients with multiple solar keratoses (SK) was compared with their number on 82 control subjects. The existence of SK served as a biologic marker for long-term solar effects.

RESULTS

On patients with SK we counted 1285 nevi (mean 10.0 nevi per person) and on control subjects, 1521 nevi (mean 18.5 nevi) (p = 0.0046; Kruskal-Wallis test). The finding that persons exhibiting signs of accumulating sun effects have fewer nevi was maintained irrespective to differences of gender, occupation, and complexion.

CONCLUSION

Our data suggest that accumulating solar effects may contribute to the natural maturation and elimination of common acquired nevi in late adulthood.

Epidemiologic evidence for the role of melanocytic nevi as risk markers and direct precursors of cutaneous malignant melanoma. Results of a case control study in melanoma patients and nonmelanoma control subjects

BACKGROUND

Melanocytic nevi (MN) are markers of melanoma risk, but their potential role as precursors of cutaneous malignant melanoma (CMM) is still controversial.

OBJECTIVE

The overall and site-specific relative risk (RR) of developing CMM was evaluated according to site-specific MN counts.

METHODS

MN prevalence by anatomic site and by age was compared in 200 CMM patients and in 200 nonmelanoma control subjects; RRs were calculated.

RESULTS

In CMM patients both MN and CMM were mainly found on the legs in women and on the posterior trunk in men, whereas in the control subjects most MN were found on the arms. MN counts on the trunk in men and on the legs in women were best predictors of the overall CMM risk (RR: 33-fold and 15-fold, respectively, for greater than 20 vs up to 4 MN). For both genders combined, the RR for CMM developing on the trunk and legs (predominant CMM locations) was best predicted by MN counts in the respective body region (RR: 24-fold and 27-fold, respectively). MN prevalence peaked in the fourth to fifth decade of life and most CMM were diagnosed during the fifth and sixth decades.

CONCLUSION

The site-specificity of melanoma risk found for high MN counts on the trunk and the legs and the close similarities in age distribution suggest that the role of MN as direct precursors of CMM has been underestimated and exceeds the number of histologically evident MN associated with CMM.

Oral contraceptives and skin neoplasia

A possible association between oral contraception and the development of cutaneous melanoma has been raised largely because of the hyperpigmentation of pregnancy and the effect pregnancy may have on the outcome of established disease. Present evidence suggests there is no causal link between oral contraceptive (OC) use and melanoma (or with benign melanocytic nevi), nor has a specific subgroup of women or subtype of melanoma been consistently implicated as being at increased risk of this disease due to use of OCs.

Prevalence of common and dysplastic naevi in a Swedish population

The naevus profile was examined in a Swedish population that was randomly selected from a census file. The participation rate was considered high at 82%. The number of common naevi (CN) and the prevalence of dysplastic naevi (DN) were investigated in 379 subjects (aged 30-50 years). The mean total body count of CN greater than or equal to 2 mm was 67 (range 1-300). As many as 22% of the population had 100 naevi or more and only 18% had less than 25. The counts were not influenced by age or sex. DN were diagnosed clinically in 18% (CI 14-22%) of the subjects and histologically in 8% (CI 5-11%). Subjects with dysplastic naevi had a significantly larger number of common naevi and a more sun-sensitive skin type than subjects without DN, P less than 0.001.

Benign pigmented nevi in children from Kidderminster, England: prevalence and associated factors

The prevalence of benign pigmented nevi in a group of 187 children, aged 8 or 9 years, was determined for each of 31 anatomic sites. Information on possible associated factors was obtained from the children's parents with a standard interview questionnaire. Pale skin color was found to be associated with a higher prevalence of nevi. A comparison of these data with recent data from Australia supports the hypotheses that (1) the number of nevi is a risk factor for melanoma and (2) groups at high risk of melanoma may be formed in childhood.

Pigmentary changes of the ageing skin

In subjects older than 25-30 years the number of enzymatically active melanocytes detectable by the dopa reaction decreases by about 10-20% per decade, with exposed skin having approximately twice as many pigment cells as unexposed skin. Chronic exposure to sunlight may stimulate the epidermal melanocyte system rather than accelerating chronological ageing. The number of melanocytic naevi declines with age. Despite the decreased melanocyte density, photoaged skin has irregular pigmentation and, frequently, there is hyperpigmentation. This may be due to greater positivity of dopa of chronically irradiated melanocytes. Heterogeneity in skin colour in exposed areas of skin is due to uneven distribution of pigment cells, a local loss of melanocytes, and a modification in the interactions between melanocytes and keratinocytes. The most common pigmented lesions in sun-exposed skin include ephelides, actinic lentigo, pigmented solar keratoses and seborrhoeic keratoses, and lentigo maligna. The white spots in aged skin are usually stellate pseudoscars or idiopathic guttate hypomelanosis. Greying of the hair is due to progressive loss of melanocytes from the hair follicles. In vivo and in vitro studies are necessary to increase overall understanding of the processes involved and to improve treatment of the pigmentary changes in ageing skin.

Age and malignant melanoma: comparison of variables in different age-groups

Variables were compared in patients with clinical stage I superficial spreading melanoma who had been divided into three age-groups. The study included 736 consecutive patients who were prospectively entered into the data base of the Melanoma Cooperative Group of New York University Medical Center. Compared with the younger patients ( less than 40 years), older patients (greater than or equal to 60 years) had superficial spreading melanomas that were, on average, of greater thickness, level, and diameter. Younger patients were more likely than older patients to show evidence that their melanomas arose from preexisting nevocytic nevi. There was no difference in the 10-year survival between groups when melanomas were matched by thickness. Thus it is as important to perform periodic total cutaneous examinations in the elderly as it is in younger persons, and age alone should not determine management strategies.

Excess benign melanocytic naevi after chemotherapy for malignancy in childhood

OBJECTIVE

To see whether children who have had chemotherapy develop increased numbers of moles.

DESIGN

Blind assessment of patients having chemotherapy and subsequent comparison with the first suitable patients matched for age and sex who were attending the clinic during the same period after having completed treatment. Controls were obtained the following year by taking the first suitable patients attending a routine dermatology outpatient clinic who matched the study groups for age and sex.

SETTING

Referrals to a paediatric oncology clinic and a dermatology clinic at two city hospitals.

PATIENTS

The group receiving chemotherapy comprised all 32 patients with acute lymphatic leukaemia, lymphoma, and rhabdomyosarcoma who were attending the paediatric oncology clinic on two mornings a week during October 1987 to March 1988. The group who had completed treatment comprised 32 patients who were attending for follow up during the same period and who matched the first group for age and sex. Thirty two other patients attending the dermatology outpatient clinic with unrelated skin conditions served as controls.

END POINT

Definite increase in numbers of moles on children after a course of chemotherapy.

MEASUREMENTS AND MAIN RESULTS

Moles were counted by one observer on defined areas of the body and divided into those less than 3 mm and greater than or equal to 3 mm diameter. Patients receiving chemotherapy had a similar number of moles to the control group. By contrast patients who had completed chemotherapy had significant increases both in moles less than 3 mm and greater than or equal to 3 mm and in the total number of moles. These patients were more likely to have moles on acral sites.

CONCLUSIONS

Children with substantially increased numbers of moles (benign melanocytic naevi) after successful chemotherapy for malignancy may have an increased risk of melanoma. They should be offered prolonged surveillance and cautioned about exposure to ultraviolet light.

Melanocytic nevi in schoolchildren in Queensland

In a group of 211 schoolchildren in Queensland less than 12 years of age, the mean total melanocytic nevus (mole) count was 28 (median 19), and the mean count for raised nevi was 11 (median 8). The upper aspect of the back and chest were the most commonly affected sites, with the neck being the third. Boys had significantly (p less than 0.01) more melanocytic nevi than girls, and prevalence was highest in children with pale skin and light-colored hair. Nonwhite heritage had a protective effect independent of pigmentary characteristics. Total numbers of nevi on children also were related to maternal tendency to large numbers of moles and to family history of melanoma. The only significant association observed for the presence of large (greater than 5 mm) nevi on children was a family history of melanoma. The children studied come from a general population that has the highest known risk of melanoma. In Australia they have been shown to have the highest prevalence of nevi ever reported in the prepubertal age group. These descriptive data, together with the specific pigmentary and family associations described, extend the known links between benign nevi and malignant melanoma.