Sarah C. Wallingford

Childhood exposure to ultraviolet radiation and harmful skin effects: epidemiological evidence.

We review the general amount and patterns of exposure to solar ultraviolet (UV) radiation that children and teenagers experience and the spectrum of UV-related skin damage that can occur as a result. Data about the amount of solar UV received by children and teenagers are relatively few but suggest that around 40-50% of total UV to age 60 occurs before age 20. Among white children, those with the palest complexions suffer the most damage. Comparisons of prevalence and incidence of outcomes in children and teenagers sharing common ancestry, but living at different latitudes, show that prevalence rates of photoaging and melanocytic naevi are higher in Australian compared with British children, and similarly for melanoma. Genetic risk for the majority of the melanomas in teens is a function of genes controlling naevus propensity and pigmentation in the skin. High numbers of naevi and freckles, red hair, blue eyes, inability to tan, as well as a family history are the primary determinants of melanoma among adolescents. Beyond the signs of skin damage seen in children are the latent effects observed later in adulthood. Childhood is believed to be a susceptible window for long-term harmful effects of UV, as evidenced by clear differences in skin cancer risk between child and adult migrants from high to low latitudes. Effective UV radiation protection from childhood is necessary to control both immediate and long-term harmful effects on childrens skin.

Increases in invasive melanoma in England, 1979-2006, by anatomical site

Background  National melanoma incidence trends with details of anatomical site have not been previously described for England.

Regional melanoma incidence in England, 1996-2006: reversal of north-south latitude trends among the young female population.

Melanoma incidence often shows an increasing latitudinal gradient from north to south among white European populations.

Three-way assessment of long-chain n-3 PUFA nutrition: by questionnaire and matched blood and skin samples.

The long-chain n-3 PUFA, EPA, is believed to be important for skin health, including roles in the modulation of inflammation and protection from photodamage. FFQ and blood levels are used as non-invasive proxies for assessing skin PUFA levels, but studies examining how well these proxies reflect target organ content are lacking. In seventy-eight healthy women (mean age 42·8, range 21-60 years) residing in Greater Manchester, we performed a quantitative analysis of long-chain n-3 PUFA nutrition estimated from a self-reported FFQ (n 75) and correlated this with n-3 PUFA concentrations in erythrocytes (n 72) and dermis (n 39). Linear associations between the three n-3 PUFA measurements were assessed by Spearman correlation coefficients and agreement between these measurements was estimated. Average total dietary content of the principal long-chain n-3 PUFA EPA and DHA was 171 (SD 168) and 236 (SD 248) mg/d, respectively. EPA showed significant correlations between FFQ assessments and both erythrocyte (r 0·57, P< 0·0001) and dermal (r 0·33, P= 0·05) levels, as well as between erythrocytes and dermis (r 0·45, P= 0·008). FFQ intake of DHA and the sum of n-3 PUFA also correlated well with erythrocyte concentrations (r 0·50, P< 0·0001; r 0·27, P= 0·03). Agreement between ranked thirds of dietary intake, blood and dermis approached 50% for EPA and DHA, though gross misclassification was lower for EPA. Thus, FFQ estimates and circulating levels of the dietary long-chain n-3 PUFA, EPA, may be utilised as well-correlated measures of its dermal bioavailability.

Skin Cancer Arising in Scars: A Systematic Review

BACKGROUND Despite numerous case reports, epidemiologic evidence regarding true rate of skin cancer in scars of any etiology is sparse. METHODS Systematic literature review of all published epidemiologic studies on skin cancer in scar tissue from surgery, ulcers, or burns using citation databases and manual review. RESULTS There were no epidemiologic data to quantify risk of skin cancer in surgical scars or chronic ulcers. Two eligible cohort studies were identified, from Denmark and Sweden, in which skin cancers in 16, 903 and 37,095 burn patients, respectively, were ascertained through cancer registry follow‐up. Each reported standardized incidence ratios (SIRs) for skin cancer types on any site that were uniformly less than unity compared with the general population. Only the Danish cohort assessed skin cancers specifically on past burn injury sites and found a burn‐site‐specific SIR of 1.2 (95% confidence interval (CI)=0.4–2.7) for squamous cell carcinoma (SCC), 0.7 (95% CI=0.4–1.1) for basal cell carcinoma, and 0.3 (95% CI=0.0–1.2) for melanoma. CONCLUSIONS Available epidemiologic data suggest that burn patients are not at higher risk of skin cancers in general, although a modest excess of SCC in burn scars cannot be excluded, nor can excess risk with longer follow‐up. Risk of skin cancer in scars other than burn scars has not been investigated epidemiologically. Renovo, Ltd., UK provided funding for this study. A. Green has been a consultant for Renovo Ltd.

Comparison of melanoma incidence and trends among youth under 25 years in Australia and England, 1990-2010.

White populations in Australia and England share many genetic and phenotypic characteristics due to common ancestry, but Australians experience far higher rates of melanoma due to higher ambient ultraviolet radiation (UVR) levels. To gain insight into the role of UVR on melanoma development early in life, we used national cancer registration data and compared recent incidence rates and long‐term trends of primary invasive cutaneous melanoma in Australian and English youth aged 0–24 years diagnosed 1990–2010. Incidence rates and standardized rate ratios (SRRs) with 95% confidence intervals (CIs) for 2006–2010 were calculated and incidence trends across the whole period were examined using JoinPoint regression. In Australian youth, overall melanoma incidence was double that in English youth (2.2 and 1.1 per 100,000, respectively). While melanoma rates were similarly rare among children <10 years in both countries, in subsequent 5‐year age groups, incidence was significantly higher in Australia compared to England. Melanoma incidence among 15–24 year olds significantly increased by more than 2% per year in both sexes in England. However, after an initial non‐significant increase, Australian rates for this older age group significantly decreased by 6.0% (95% CI, −8.2 to −3.8) per year in females from 1997 and decreased by 12.4% (95% CI, −20.3 to −3.8) per year in males from 2004. Long‐standing primary prevention strategies targeted at curbing UVR exposure appear to have been effective in mitigating incidence trends in Australian youth, but decreases in incidence in English youth are yet to be observed.

Plasma omega-3 and omega-6 concentrations and risk of cutaneous basal and squamous cell carcinomas in Australian adults

Laboratory-based evidence suggests that omega-3 and omega-6 polyunsaturated fatty acids may affect skin photocarcinogenesis, but epidemiologic evidence is inconsistent. In 1,191 White Australian adults, we prospectively investigated associations between baseline plasma concentrations of omega-3 and omega-6 fatty acids and cutaneous basal cell carcinomas (BCC) and squamous cell carcinomas (SCC). Relative risks (RR) and 95% confidence intervals (CI) were estimated on the basis of number of histologically confirmed tumors diagnosed during follow-up (1997–2007). Plasma eicosapentaenoic acid (EPA) concentrations and omega-3/-6 ratio showed significant inverse associations with SCC tumors, comparing higher tertiles with the lowest, in age- and sex-adjusted models (Ptrend = 0.02 and 0.03, respectively) which weakened after adjustment for past sun exposure. Associations between EPA and SCC were stronger among participants with a history of skin cancer at baseline (n = 378; highest vs. lowest tertile: RR = 0.50; 95% CI, 0.28–0.92; Ptrend = 0.01). Total omega-6 was inversely associated with BCC tumors in multivariate models (P = 0.04; highest vs. lowest tertile: RR = 0.71; 95% CI, 0.51–0.99), and more strongly in the subgroup with past skin cancer. Linoleic and linolenic acids were also inversely associated with BCC occurrence in this subgroup. When fatty acids were analyzed as continuous variables, however, there was no evidence of any linear or nonlinear associations. This study provides some support for reduced skin cancer risk with high plasma concentrations of omega-3 and omega-6 fatty acids, but results depended on how fatty acid data were modeled. Further investigation of these associations in larger datasets is needed. Cancer Epidemiol Biomarkers Prev; 22(10); 1900–5. ©2013 AACR.