13. Cancers attributable to solar (ultraviolet) radiation exposure in the UK in 2010

Fyn is a redox sensor involved in solar ultraviolet light-induced signal transduction in skin carcinogenesis

Solar ultraviolet (UV) light is a major etiological factor in skin carcinogenesis, with solar UV-stimulated signal transduction inducing pathological changes and skin damage. The primary sensor of solar UV-induced cellular signaling has not been identified. We use an experimental system of solar simulated light (SSL) to mimic solar UV and we demonstrate that Fyn is a primary redox sensor involved in SSL-induced signal transduction. Reactive oxygen species (ROS) generated by SSL exposure directly oxidize Cys488 of Fyn, resulting in increased Fyn kinase activity. Fyn oxidation was increased in mouse skin after SSL exposure, and Fyn knockout (Fyn^−/−) mice formed larger and more tumors compared to Fyn wildtype mice when exposed to SSL for an extended period of time. Murine embryonic fibroblasts (MEFs) lacking Fyn as well as cells in which Fyn expression was knocked down were resistant to SSL-induced apoptosis. Furthermore, cells expressing mutant Fyn (C448A) were resistant to SSL-induced apoptosis. These findings suggest that Fyn acts as a regulatory nexus between solar UV, ROS and signal transduction during skin carcinogenesis.

Substantial contribution of extrinsic risk factors to cancer development

Recent research has highlighted a strong correlation between tissue-specific cancer risk and the lifetime number of tissue-specific stem cell divisions. Whether such correlation implies a high unavoidable intrinsic cancer risk has become a key public health debate with dissemination of the ‘bad luck’ hypothesis. Here we provide evidence that intrinsic risk factors contribute only modestly (<10~30%) to cancer development. First, we demonstrate that the correlation between stem-cell division and cancer risk does not distinguish between the effects of intrinsic and extrinsic factors. Next, we show that intrinsic risk is better estimated by the lower bound risk controlling for total stem cell divisions. Finally, we show that the rates of endogenous mutation accumulation by intrinsic processes are not sufficient to account for the observed cancer risks. Collectively, we conclude that cancer risk is heavily influenced by extrinsic factors. These results carry immense consequences for strategizing cancer prevention, research, and public health.

Skin cancer prevention practices among malignant melanoma survivors: a systematic review

PURPOSE

This systematic review was conducted to evaluate and summarize the existing literature on prevalence of ultraviolet radiation (UVR) exposure, sun protection, and screening behaviors among individuals diagnosed with malignant melanoma (MM).

METHODS

The search was performed in PubMed, CINAHL, PsycINFO, ScienceDirect, EMBASE, and ERIC from inception of each database through July 2014. Studies were included if (1) individuals diagnosed with MM were the primary sample, (2) measured UVR exposure, primary and secondary preventive behaviors, (3) original research communication that constitutes an entire set of empirical data, (4) observational design, and (5) English peer-reviewed. Studies were excluded if (1) all of the inclusion criteria were not met and (2) duplicates, conference abstracts, editorials, news, letters to the editor, comments, reviews, feature articles, white papers, and guidelines.

RESULTS

The search resulted in 255 articles that were screened for relevance; however, only 15 articles met all of the inclusion criteria. Most of the studies were cross-sectional (n = 10), used self-administered surveys (n = 8), and were conducted in North America (n = 10). The sample sizes ranged considerably, but were mostly Caucasian (n = 6) and included a higher proportion of women (n = 8). Evidence demonstrated that individuals with MM still engaged in sunbathing, indoor tanning, and reported sunburns. Moreover, survivors reported inadequate levels of both sun protection and skin self-examinations.

CONCLUSIONS

The findings highlight the need for intensifying intervention strategies to reduce the risk of new primary MMs in this group. Future research should increase in rigor and include more diverse populations and regions.

European Code against Cancer 4th Edition: Ultraviolet radiation and cancer

Ultraviolet radiation (UVR) is part of the electromagnetic spectrum emitted naturally from the sun or from artificial sources such as tanning devices. Acute skin reactions induced by UVR exposure are erythema (skin reddening), or sunburn, and the acquisition of a suntan triggered by UVR-induced DNA damage. UVR exposure is the main cause of skin cancer, including cutaneous malignant melanoma, basal-cell carcinoma, and squamous-cell carcinoma. Skin cancer is the most common cancer in fair-skinned populations, and its incidence has increased steeply over recent decades. According to estimates for 2012, about 100,000 new cases of cutaneous melanoma and about 22,000 deaths from it occurred in Europe. The main mechanisms by which UVR causes cancer are well understood. Exposure during childhood appears to be particularly harmful. Exposure to UVR is a risk factor modifiable by individuals' behaviour. Excessive exposure from natural sources can be avoided by seeking shade when the sun is strongest, by wearing appropriate clothing, and by appropriately applying sunscreens if direct sunlight is unavoidable. Exposure from artificial sources can be completely avoided by not using sunbeds. Beneficial effects of sun or UVR exposure, such as for vitamin D production, can be fully achieved while still avoiding too much sun exposure and the use of sunbeds. Taking all the scientific evidence together, the recommendation of the 4th edition of the European Code Against Cancer for ultraviolet radiation is: "Avoid too much sun, especially for children. Use sun protection. Do not use sunbeds."

Vitamin D and the skin: Focus on a complex relationship: A review

The "sunshine" vitamin is a hot topic that attracted ample attention over the past decades, specially that a considerable proportion of the worldwide population are deficient in this essential nutrient. Vitamin D was primarily acknowledged for its importance in bone formation, however; increasing evidence point to its interference with the proper function of nearly every tissue in our bodies including brain, heart, muscles, immune system and skin. Thereby its deficiency has been incriminated in a long panel of diseases including cancers, autoimmune diseases, cardiovascular and neurological disorders. Its involvement in the pathogenesis of different dermatological diseases is no exception and has been the subject of much research over the recent years. In the current review, we will throw light on this highly disputed vitamin that is creating a significant concern from a dermatological perspective. Furthermore, the consequences of its deficiency on the skin will be in focus.

Cancers in Australia attributable to exposure to solar ultraviolet radiation and prevented by regular sunscreen use

OBJECTIVES

To estimate the proportion and numbers of cancers occurring in Australia attributable to solar ultraviolet radiation (UVR) and the proportion and numbers prevented by regular sun protection factor (SPF) 15+ sunscreen use.

METHODS

We estimated the population attributable fraction (PAF) and numbers of melanomas and keratinocyte cancers (i.e. basal cell carcinomas and squamous cell carcinomas) due to exposure to ambient UVR resulting from residing in Australia versus residing in the UK (for melanoma) or Scandinavia (for keratinocyte cancers). We also estimated the prevented fraction (PF): the proportion of cancers that would have occurred but were likely prevented by regular sunscreen use.

RESULTS

An estimated 7,220 melanomas (PAF 63%) and essentially all keratinocyte cancers occurring in Australia were attributable to high ambient UVR levels in Australia. We estimated that regular sunscreen use prevented around 14,190 (PF 9.3%) and 1,730 (PF 14%) people from developing SCC and melanoma, respectively.

CONCLUSIONS

Although our approach was conservative, a high proportion of skin cancers in Australia are attributable to high ambient levels of UVR. Prevailing levels of sunscreen use probably reduced skin cancer incidence by 10-15%.

IMPLICATIONS

Most skin cancers are preventable. Sunscreen should be a component of a comprehensive sun protection strategy.

Seasonal variation in diagnosis of invasive cutaneous melanoma in Eastern England and Scotland

BACKGROUND

Worldwide, the incidence of cutaneous melanoma has been reported to be highest in the summer and lowest in the winter. Northern Irish data suggested seasonal variation for women only, especially those with thinner melanomas, sited on limbs. We interrogated two larger UK cancer registries for temporal differences in melanoma diagnosis and associated patient characteristics.

METHODS

Melanomas diagnosed from 2006 to 2010 in the Eastern England and Scottish cancer registries (n=11,611) were analysed by month of diagnosis, patient demographics and melanoma characteristics, using descriptive and multivariate modelling methods.

RESULTS

More patients with melanoma were diagnosed in the summer months (June 9.9%, July 9.7%, August 9.8%) than the winter months (December 7.2%, January 7.2%, February 7.1%) and this pattern was consistent in both regions. There was evidence that the seasonal patterns varied by sex (p=0.015), melanoma thickness (p=0.002), body site (p=0.006), and type (superficial spreading melanomas p=0.005). The seasonal variation was greatest for diagnosis of melanomas occurring on the limbs.

CONCLUSION

This study has confirmed seasonal variation in melanoma diagnosis in Eastern England and Scotland across almost all population demographics and melanoma characteristics studied, with higher numbers diagnosed in the summer months, particularly on the limbs. Seasonal patterns in skin awareness and related help-seeking are likely to be implicated. Targeted patient interventions to increase sun awareness and encourage year-long skin inspection are warranted.

A Left-Sided Prevalence of Lentigo Maligna: A UK Based Observational Study and Review of the Evidence

Skin cancer has been shown to present asymmetrically, prevalent on the left side of the body, more so in subtypes of cutaneous melanoma such as lentigo maligna. Biases have been linked to cumulative UV light exposure and automobile driving patterns. Though left-right ratios have previously correlated with the side men or women tend to position themselves or countries drive on, more recent trends indicate a consistent left-sided bias. To clarify reasons for changing trends, a review of the evidence base and LM's laterality in a UK cohort (99 cases 2000–2011) was conducted for the first time. The strong correlation of left-sided excess, found in both genders (ratios 1.381–1.5, P < 0.05  X² 0.841), is congruent with more recent findings. Though evidence indicates that driving position is no longer a risk factor for LM, due most likely to improved car window UV protection, it remains the most commonly attributed cause. Understanding phenomena such as UV lights “scatter effect” or that cumulative exposure may not be a significant risk factor helps rationalize older conclusions that would otherwise appear contradictory. The reasons for left-sided excess remain unclear but may be due to factors requiring further research such as the body's anatomical/embryological asymmetry.

Skin cancer, irradiation, and sunspots: the solar cycle effect

Skin cancer is diagnosed in more than 2 million individuals annually in the United States. It is strongly associated with ultraviolet exposure, with melanoma risk doubling after five or more sunburns. Solar activity, characterized by features such as irradiance and sunspots, undergoes an 11-year solar cycle. This fingerprint frequency accounts for relatively small variation on Earth when compared to other uncorrelated time scales such as daily and seasonal cycles. Kolmogorov-Zurbenko filters, applied to the solar cycle and skin cancer data, separate the components of different time scales to detect weaker long term signals and investigate the relationships between long term trends. Analyses of crosscorrelations reveal epidemiologically consistent latencies between variables which can then be used for regression analysis to calculate a coefficient of influence. This method reveals that strong numerical associations, with correlations >0.5, exist between these small but distinct long term trends in the solar cycle and skin cancer. This improves modeling skin cancer trends on long time scales despite the stronger variation in other time scales and the destructive presence of noise.

Vitamin D and melanoma and non-melanoma skin cancer risk and prognosis: a comprehensive review and meta-analysis

Vitamin D is formed mainly in the skin upon exposure to sunlight and can as well be taken orally with food or through supplements. While sun exposure is a known risk factor for skin cancer development, vitamin D exerts anti-proliferative and pro-apoptotic effects on melanocytes and keratinocytes in vitro. To clarify the role of vitamin D in skin carcinogenesis, we performed a review of the literature and meta-analysis to evaluate the association of vitamin D serum levels and dietary intake with cutaneous melanoma (CM) and non-melanoma skin cancer (NMSC) risk and melanoma prognostic factors. Twenty papers were included for an overall 1420 CM and 2317 NMSC. The summary relative risks (SRRs) from random effects models for the association of highest versus lowest vitamin D serum levels was 1.46 (95% confidence interval (CI) 0.60-3.53) and 1.64 (95% CI 1.02-2.65) for CM and NMSC, respectively. The SRR for the highest versus lowest quintile of vitamin D intake was 0.86 (95% CI 0.63-1.13) for CM and 1.03 (95% CI 0.95-1.13) for NMSC. Data were suggestive of an inverse association between vitamin D blood levels and CM thickness at diagnosis. Further research is needed to investigate the effect of vitamin D on skin cancer risk in populations with different exposure to sunlight and dietary habits, and to evaluate whether vitamin D supplementation is effective in improving CM survival.

Scottish adolescents' sun-related behaviours, tanning attitudes and associations with skin cancer awareness: a cross-sectional study

OBJECTIVES

To describe Scottish adolescents' sun-related behaviours and tanning attitudes and assess associations with skin cancer awareness.

DESIGN

Cross-sectional study.

SETTING

20 state secondary schools in one Scottish local authority (Glasgow City).

PARTICIPANTS

2173 adolescents (females: 50.7%, n=1102) with a mean age of 12.4 (SD=0.55).

OUTCOME MEASURES

Sun-related behaviour (suntan, sunbathing, sunburn, sunscreen use, sunbed use), tanning attitudes, skin cancer-related symptom and risk factor awareness.

RESULTS

Adolescents reported poor sun-related practice: 51% of adolescents reported sunburn the previous summer of whom 38% indicated sunburn on more than one occasion. Skin cancer awareness was low: 45% recognised 'change in the appearance of a mole' as a cancer symptom, and 39% agreed that 'getting sunburnt more than once as a child' increased cancer risk. 42% and 26% of adolescents, respectively, reported that friends and family held protanning attitudes. Compared with males, females were statistically significantly more likely to: report sunbathing (p<0.001), use of lotions or oil to aid tanning (p=0.009) and sunburn (p<0.001); know that changes in the appearance of a mole was a skin cancer symptom (p=0.036) and sunburn more than once as a child was a skin cancer risk factor (p=0.005); perceive their friends to hold protanning attitudes (p<0.001) and indicate that a tan made them feel better about themselves (p<0.001), more attractive to others (p=0.011) and healthier (p<0.001).

CONCLUSIONS

Scottish adolescents had poor sun protection practice and low skin cancer awareness. Girls adopted riskier sun-related behaviour despite greater awareness of skin cancer-related risk. Urgent action is required to promote positive sun-related behaviour and increase skin cancer awareness among Scottish adolescents. However, further research is needed to inform the development of effective sun-safe interventions.

The risk of developing a second primary cancer in melanoma patients: a comprehensive review of the literature and meta-analysis

The number of cutaneous melanoma survivors has been increasing for years due to improvements in early diagnosis and subsequent prolonged survival. These patients are at increased risk of developing a second melanoma and a second primary malignancy (SPM) at other sites as well. We performed a review of scientific literature and meta-analysis to evaluate the risk of developing a SPM (other than melanoma) among melanoma patients. Twenty-three independent papers and over 350,000 melanoma patients were included. Risk of cancer among melanoma survivors was increased overall (1.57, 95% CI 1.29-1.90) and at several sites: bone (2.09, 95% CI 1.08-4.05), non-melanoma skin cancer (4.01, 95% CI 1.81-8.87), soft tissue (6.80, 95% CI 1.29-35.98), colon-rectum (1.12, 95% CI 1.00-1.25), female breast (1.14, 95% CI 1.07-1.22), kidney (1.34, 95% CI 1.23-1.45), prostate (1.25, 95% CI 1.13-1.37) and non-Hodgkin lymphoma (1.37, 95% CI 1.22-1.54). The overall risk of SPM showed a tendency to decrease as the time from melanoma diagnosis lengthened. Most of our findings may be explained by the tendency of some exposures, which are risk factors for different tumors, to occur simultaneously in the same individuals. These results suggest primary and secondary cancer prevention counselling for melanoma survivors.

Ultraviolet damage to the eye revisited: eye-sun protection factor (E-SPF®), a new ultraviolet protection label for eyewear

Ultraviolet (UV) radiation potentially damages the skin, the immune system, and structures of the eye. A useful UV sun protection for the skin has been established. Since a remarkable body of evidence shows an association between UV radiation and damage to structures of the eye, eye protection is important, but a reliable and practical tool to assess and compare the UV-protective properties of lenses has been lacking. Among the general lay public, misconceptions on eye-sun protection have been identified. For example, sun protection is mainly ascribed to sunglasses, but less so to clear lenses. Skin malignancies in the periorbital region are frequent, but usual topical skin protection does not include the lids. Recent research utilized exact dosimetry and demonstrated relevant differences in UV burden to the eye and skin at a given ambient irradiation. Chronic UV effects on the cornea and lens are cumulative, so effective UV protection of the eyes is important for all age groups and should be used systematically. Protection of children's eyes is especially important, because UV transmittance is higher at a very young age, allowing higher levels of UV radiation to reach the crystalline lens and even the retina. Sunglasses as well as clear lenses (plano and prescription) effectively reduce transmittance of UV radiation. However, an important share of the UV burden to the eye is explained by back reflection of radiation from lenses to the eye. UV radiation incident from an angle of 135°-150° behind a lens wearer is reflected from the back side of lenses. The usual antireflective coatings considerably increase reflection of UV radiation. To provide reliable labeling of the protective potential of lenses, an eye-sun protection factor (E-SPF®) has been developed. It integrates UV transmission as well as UV reflectance of lenses. The E-SPF® compares well with established skin-sun protection factors and provides clear messages to eye health care providers and to lay consumers.

Vemurafenib for the treatment of locally advanced or metastatic BRAF V600 mutation-positive malignant melanoma: a NICE single technology appraisal

Vemurafenib is an oral BRAF inhibitor licenced for the treatment of locally advanced or metastatic BRAF V600-mutation positive malignant melanoma. The manufacturer of vemurafenib, Roche Products Limited, was invited by the National Institute for Health and Care Excellence (NICE) to submit evidence of the drug's clinical- and cost-effectiveness for its licenced indication, to inform the Institute's Single Technology Appraisal (STA) process. The Liverpool Reviews and Implementation Group (LRiG) at the University of Liverpool was commissioned to act as the Evidence Review Group (ERG) for this appraisal. This article summarises the ERG's review of the evidence submitted by the manufacturer and also includes a summary of the NICE Appraisal Committee (AC) decision. The ERG reviewed the clinical- and cost-effectiveness evidence in accordance with the decision problem defined by NICE. The ERG's analysis of the submitted economic model assessed the appropriateness of the approach taken by the manufacturer in modelling the decision problem. It also included an assessment of the reliability of model implementation and the extent of conformity to published standards and prevailing norms of practice within the health economics modelling community. Particular attention was paid to issues likely to impact substantially on the base-case cost-effectiveness results. The clinical evidence was derived from BRIM 3 (BRAF Inhibitor in Melanoma 3), a well-designed, multi-centre, multi-national, phase III, randomised controlled trial (RCT). Clinical outcome results from the October 2011 data cut showed that median overall survival for patients treated with vemurafenib was 13.2 months compared with 9.6 months for those treated with dacarbazine. The ERG's main concern with the trial was the potential for confounding because of the early introduction of the crossover from the comparator drug to vemurafenib or another BRAF inhibitor. The submitted incremental cost-effectiveness ratio (ICER) was considered above the NICE threshold, even when end-of-life criteria were taken into account. The ERG questioned the submitted economic model on a number of grounds, particularly the approach used to project trial results. After the ERG had made appropriate corrections to the model and employed an alternative form of projective modelling, the ICER per quality-adjusted life year more than doubled. Additional evidence was submitted by the manufacturer for consideration at a second AC meeting and at their third meeting the AC concluded that vemurafenib could be recommended as first-line maintenance treatment for patients with locally advanced or metastatic BRAF V600 mutation-positive malignant melanoma.

Adolescents' awareness of cancer risk factors and associations with health-related behaviours

Increasing adolescents' awareness of the contribution of modifiable lifestyle factors to cancer risk may influence life-long patterns of healthy behaviour. However, little is known about adolescents' awareness of cancer risk factors and the effectiveness of awareness-raising interventions. This study assessed adolescents' cancer awareness and the effectiveness of an existing cancer-specific school-based intervention delivered by Teenage Cancer Trust. The Cancer Awareness Measure was completed by 478 adolescents (male: 250, 52.3%) aged 11-17 years (mean: 13.8, standard deviation: 1.24) in four UK schools; 422 adolescents provided paired data 2 weeks before and 2 weeks after the intervention delivered in 3 schools, and twice 4 weeks apart in the fourth (control) school. Adolescents recognized on average 4.4 (of 11) cancer risk factors. With the exception of smoking, adolescents' awareness of cancer risk factors was low. Awareness significantly increased after the intervention (4.6-5.7, P < 0.001). There was no significant change in the control school. Intervention effect was greater among females. This educational intervention is an effective way to raise adolescents' awareness of cancer risk factors. However, further cross-sectional and experimental studies are required to definitively assess adolescents' awareness of cancer risk factors and the effectiveness of this educational intervention.