Monitoring of nevus density in children as a method to detect shifts in melanoma risk in the population

Future reduction of cutaneous malignant melanoma due to improved sun protection habits and decreased common melanocytic nevi density among Swedish children?: A follow-up from 2002 to 2012

We have previously demonstrated significant improvements in sun protection regimens and significantly fewer common melanocytic nevi (CMN) among 7-year-old children in southern Sweden when comparing year 2007 with 2002. The aim of this study was to investigate whether the observed decreasing trend also can be observed at age 10 and, in addition, to compare the CMN density change between 7 and 10 years of age during two periods of time. Two open cohorts were used, cohort I with schoolchildren investigated in 2002 at age 7 and in 2005 at age 10 and cohort II with schoolchildren investigated in 2009 at age 7 and in 2012 at age 10. A significant decrease in CMN density (number/m² BSA) at age 10 from 2005 to 2012 was observed: 15.9 (14.7-17.2) and 11.4 (10.1-12.7), respectively. The density growth rate from 7 to 10 years was 2.8 (2.1-3.5) between 2002 and 2005 and decreased significantly to 0.9 (0.2-1.5) between 2009 and 2012. Significant increases were observed for 'often use of sunscreen', 'often staying in shade' and 'often staying indoors' from cohort I to cohort II: 65 vs 80%, 7.6 vs 13% and 7.3 vs 19%, respectively. The decrease in number of CMN among 10-year-old children confirms a current trend in Sweden. If this persists, a future reduction of cutaneous malignant melanoma incidence in Sweden might be anticipated. The results also indicate that CMN count could be used as an indicator of ultraviolet exposure.

Cutaneous melanoma primary site is linked to nevus density

There are at least two pathways driving cutaneous melanoma; one is linked to an inherent melanoma susceptibility to nevi development and the second to environmental cumulative ultraviolet light exposure. In this study, we examined the relation between nevus density, accrued sun damage and the site of primary melanoma excision. In a series of 888 consecutive cutaneous melanoma patients, melanomas appearing in skin areas with a high relative nevus density were most prominent in men, with an elevated nevus count, at sites without solar elastosis, but with an epidemiological history of previous sunburn. The present study associates melanoma development to sites with high nevus density. Our study supports more careful surveillance of body areas with increased nevus density in patients with high total body number of nevi, especially when they report a history of sunburns at these sites.

Monitoring of naevus density at age 6: Is it both feasible and meaningful?

BACKGROUND

Instruments for the evaluation of campaigns targeting the reduction of UV exposure in the population, and thus skin cancer risk, are needed.

OBJECTIVE

To examine the "childhood monitoring of naevus density" approach suggested some 10 years ago in a routine setting of mandatory pre-school examinations.

METHODS

Data were collected between 1999 and 2005 in Göttingen, Wolfenbüttel, Northeim, Salzgitter, and Erlangen. Besides basic data, freckling, iris and hair colour, and "Fitzpatrick skin type" as well as counts of melanocytic naevi were documented. Negative binomial regression analysis quantified the association between naevus counts and above factors, and year and site of examination, respectively.

RESULTS

Of 12,809 children examined at five different sites over a period of 6 years, 11,345 were eligible for the analysis. While differences between sites were marked and significant, only a very minute, albeit significant, decrease in risk was found between the reference group (Göttingen 1999/2000) and the last year examined in Göttingen (2005).

CONCLUSIONS

Significant between-site variation in the analysis adjusted for constitutional factors points to problems with standardization; thus, a broad application of this instrument does not seem to be advisable.

Melanocytic nevi in children of southern Italy: dermoscopic, constitutional, and environmental factors

The objective was to estimate the prevalence of melanocytic nevi (MN) in children and to determine their dermoscopic characteristics and relationship with anatomic location and environmental and constitutional factors. The population was a randomly selected sample of 144 children who attended primary schools in Naples, Italy. Before physical examination of the children, standardized interviews were conducted with their parents. Follow-up interviews of both the children and parents were conducted 1 year later. Photographic and dermoscopic images were obtained. Boys had more MN than girls; 465 MN (55.6%) were observed in boys and 371 (44.4%) in girls (p < 0.05). The trunk and neck were the most common locations of MN (p < 0.001). The main dermoscopic feature of all MN observed was a globular pattern (p < 0.001). A significant correlation between duration of sunbathing and MN counts was revealed (p < 0.05). At 1-year follow-up, 118 new MN were identified in 66 children. The trunk and neck areas were the most common regions involved in the appearance of new MN (n = 68, 57.6% of all new MN, p < 0.001). The new MN count was significantly higher in children who reported more sunbathing (p < 0.001). Changes in the dermoscopic pattern were observed in 45 persistent MN, demonstrating more MN with a reticular-globular pattern, especially on the trunk, neck, and upper extremities (p < 0.001). MN development in early life is the result of complicated relationships between nevus evolution, anatomic location, and environmental and constitutional factors.

Differential volatile signatures from skin, naevi and melanoma: a novel approach to detect a pathological process

Background

Early detection of melanoma is of great importance to reduce mortality. Discovering new melanoma biomarkers would improve early detection and diagnosis. Here, we present a novel approach to detect volatile compounds from skin.

Methods and Findings

We used Head Space Solid Phase Micro-Extraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS) to identify volatile signatures from melanoma, naevi and skin samples. We hypothesized that the metabolic state of tissue alters the profile of volatile compounds. Volatiles released from fresh biopsy tissue of melanoma and benign naevus were compared based on their difference in frequency distribution and their expression level. We also analyzed volatile profiles from frozen tissue, including skin and melanoma.

Conclusions

Three volatiles, 4-methyl decane, dodecane and undecane were preferentially expressed in both fresh and frozen melanoma, indicating that they are candidate biomarkers. Twelve candidate biomarkers evaluated by fuzzy logic analysis of frozen samples distinguished melanoma from skin with 89% sensitivity and 90% specificity. Our results demonstrate proof-of-principle that there is differential expression of volatiles in melanoma. Our volatile metabolomic approach will lead to a better understanding of melanoma and can enable development of new diagnostic and treatment strategies based on altered metabolism.

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.

Appearance of melanocytic nevi on the backs of young Australian children: a 7-year longitudinal study

To determine the rate of appearance of nevi in a cohort of children between ages 6 and 12 years. The number of nevi has been established as the strongest known risk factor for melanoma, but whether the rate at which nevi appear during childhood varies by age is not well understood. The study involved analysis of nevus development over time in a cohort of 640 Western Australian school children who formed the control group in the Kidskin intervention trial. Children were assessed at ages 6, 10 and 12 years, with nevi on the back counted from photographs. The changes in both number and density of nevi between ages 6 and 12 years were linear with respect to age. The number and density of nevi increased at a greater rate for boys compared with girls; for children with blue, hazel and green eyes compared with those with brown eyes; for blonde versus dark haired children and for children with heavy freckling compared with those with no freckles. In conclusion, further research is needed to determine whether the linear increase in nevi continues into adolescence. If so, it suggests that skin cancer prevention campaigns should target older children and adolescents as well as younger children. Longitudinal studies have important advantages over cross-sectional studies in the description of nevus development with age, and should be the preferred study design.

Melanocyte biology and skin pigmentation

Melanocytes are phenotypically prominent but histologically inconspicuous skin cells. They are responsible for the pigmentation of skin and hair, and thereby contribute to the appearance of skin and provide protection from damage by ultraviolet radiation. Pigmentation mutants in various species are highly informative about basic genetic and developmental pathways, and provide important clues to the processes of photoprotection, cancer predisposition and even human evolution. Skin is the most common site of cancer in humans. Continued understanding of melanocyte contributions to skin biology will hopefully provide new opportunities for the prevention and treatment of skin diseases.

MC1R, ASIP, and DNA Repair in Sporadic and Familial Melanoma in a Mediterranean Population

BACKGROUND

Melanoma risk factors include fair pigmentation, multiple nevi, low DNA repair capacity, and CDKN2A or CDK4 mutations. Variants of the melanocortin-1 receptor (MC1R) gene have been associated with fair pigmentation and melanoma risk, and a polymorphism of the Agouti Signaling Protein (ASIP) gene has been associated with dark pigmentation. We examined MC1R and ASIP genotypes in relation to phenotypic characteristics, sporadic and familial melanoma risk, and melanoma thickness as an indicator of disease progression in a Mediterranean population.

METHODS

We studied 267 melanoma patients and 382 control subjects from a case-control study and a family study in northeastern Italy. Host factors were assessed by physical examination, questionnaire, spectrophotometer, and minimal erythema dose measurement. MC1R was sequenced, ASIP was genotyped, and DNA repair capacity was measured by the host-cell reactivation assay. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression models. Effect modification of the association between MC1R and melanoma risk by phenotypic characteristics and DNA repair capacity was also assessed. All statistical tests were two-sided.

RESULTS

Carrying MC1R variant alleles was associated with a two- to fourfold increase in risk of both sporadic and familial melanoma compared with carrying wild-type MC1R, particularly in individuals carrying multiple variant alleles (OR = 3.9; 95% CI = 3.3 to 4.6). This association was stronger in individuals with fewer additional risk factors (those with dark skin or few nevi). MC1R variant allele carriers were also three to four times more likely than were non-carriers to have thick melanomas. The ASIP polymorphism was not associated with pigmentation, nevi, or melanoma risk.

CONCLUSIONS

MC1R was associated with melanoma risk and progression in a Mediterranean population, particularly in the absence of other strong risk factors, such as freckling or many nevi.