Public awareness regarding UV risks and vitamin D--the challenges for UK skin cancer prevention campaigns

Since 1970s, incidence rates for malignant melanoma have been among the fastest rising of all cancers in the UK. Compared to other cancers, melanoma affects disproportionately more young people, and non-melanoma skin cancers are the most commonly diagnosed, with over 100,000 new cases estimated in the UK annually. Government targets to reduce skin cancer incidence have led working groups and prevention campaigns to be set up in the belief that moderating UV exposure will help. An increased awareness of skin cancer has clearly played a role in curbing mortality from the disease, but translating knowledge into behaviour change in this context is a slow and complex process, and campaigns need to be sustained if they are to impact on incidence. A growing body of literature suggesting a cancer protective role for vitamin D and sun exposure presents further challenges for skin cancer prevention campaigns, no more so than when exaggerated claims for the health benefits of sunbathing make the media spotlight. The UK population tend to need little encouragement to make the most of sunshine, and this is especially true for the younger generation who most need to take care. Public health messages to avoid the midday sun, not to burn and to protect children should not adversely affect outdoor activity or population vitamin D levels, but it is important that they are targeted to those most at risk and are consistent. More research is required to establish optimal levels of vitamin D and how to safely achieve them in a heterogeneous population. In the meantime, hasty alterations of public health messages are likely to prove counterproductive.     

Risks and benefits of sun exposure: implications for public health practice based on the Australian experience

Over recent years, evidence has been accumulating that vitamin D has a positive impact on our overall health. This may have an impact on the future of our public health advice related to skin cancer prevention. This paper explores, from a public health perspective based on Australian experience, how skin cancer prevention messages should be managed in light of new information about vitamin D and, in particular, the times when sun protection advice should be provided and how the vitamin D message can be complementary to the sun protection message.     

Influence of age,gender, educational level and self-estimation of skin type on sun exposure habits and readiness to increase sun protection

Background: Sun exposure habits and the propensity to undertake sun protection differ between individuals. Not least in primary prevention of skin cancer, aiming at reducing ultraviolet (UV) exposure, knowledge about these factors may be of importance. The aim of the present study was to investigate, in a primary health care (PHC) population, the relationship between sun exposure habits/sun protection behaviour/readiness to increase sun protection and gender, age, educational level and skin UV-sensitivity. Methods: The baseline data from a previously performed RCT on skin cancer prevention was used. 415 patients, aged >18 years, visiting a PHC centre in southern Sweden, filled-out a questionnaire mapping sun exposure, readiness to increase sun protection according to the Transtheoretical Model of Behaviour Change (TTM), and the above mentioned factors. Results: Female gender was associated with more frequent suntanning (p < 0.001) and sunbed use (p < 0.05), but also with more extensive sunscreen use (p < 0.001). High age was in general associated with low level of sun exposure and high level of protection. Subjects with low educational level reported less frequent sunscreen use than those with higher educational level, and also chose lower SPF (p < 0.001). For almost all parameters, high skin UV-sensitivity was associated with markedly lower sun exposure (p < 0.001) and more pronounced readiness to increase sun protection. Females and subjects with high educational level reported higher readiness to increase sunscreen use than males and subjects with lower educational level (p < 0.001). Conclusions: Gender, age, educational level and skin type appear to be important factors affecting sun exposure habits and sun protection behaviour, which supports the idea of appropriate mapping of these factors in patients in order to individualise sun protection advice according to the individual patient situation and capabilities.     

Nucleotide excision repair and cancer

Nucleotide excision repair (NER) is the most versatile and best studied DNA repair system in humans. NER can repair a variety of bulky DNA damages including UV-light induced DNA photoproducts. NER consists of a multistep process in which the DNA lesion is recognized and demarcated by DNA unwinding. Then, a ~28 bp DNA damage containing oligonucleotide is excised followed by gap filling using the undamaged DNA strand as a template. The consequences of defective NER are demonstrated by three rare autosomal-rezessive NER-defective syndromes: xeroderma pigmentosum (XP), Cockayne syndrome (CS), and trichothiodystrophy (TTD). XP patients show severe sun sensitivity, freckling in sun exposed skin, and develop skin cancers already during childhood. CS patients exhibit sun sensitivity, severe neurologic abnormalities, and cachectic dwarfism. Clinical symptoms of TTD patients include sun sensitivity, freckling in sun exposed skin areas, and brittle sulfur-deficient hair. In contrast to XP patients, CS and TTD patients are not skin cancer prone. Studying these syndromes can increase the knowledge of skin cancer development including cutaneous melanoma as well as basal and squamous cell carcinoma in general that may lead to new preventional and therapeutic anticancer strategies in the normal population.     

Recognizing Latinos’ range of skin pigment and phototypes to enhance skin cancer prevention

Latinos in the United States may have the mistaken assumption that their natural pigmentation protects them from developing skin cancer that, effectively, serves as a barrier to Latinos receiving education in primary and secondary prevention of skin cancer. Latino adults of Mexican or Puerto Rican heritage attending community health fairs in the greater Chicago area responded to a culturally informed and sensitive measure for sunburn and tan, which was previously adapted to capture skin irritation with tenderness from the sun occurring in darker skin types (n = 350). By self‐reported responses and spectrophotometry assessment of constitutive pigmentation, adapted Fitzpatrick skin types (FST) ranged from skin type I–IV in the Mexican American participants and from II to V in the Puerto Rican participants. The objectively measured proportion of adapted FST II skin type was greater than commonly perceived and demonstrated that many Latinos do indeed have sun‐sensitive skin.     

The impact of skin cancer prevention efforts in New South Wales,Australia: Generational trends in melanoma incidence and mortality

BackgroundIn Australia, skin cancer awareness campaigns have focused on raising the awareness and consequences of skin cancer and highlighting the importance of utilising sun protection.MethodsTrends in melanoma incidence and mortality have been explored elsewhere in Australia and this study sought to examine the trends in NSW. Anonymised incidence and mortality data for in situ and invasive melanoma from 1988 to 2014 were obtained from the NSW Cancer Registry. Trends of melanoma incidence and mortality were analysed using segmented regression to allow for changes over time. Birth cohort patterns were assessed using age–period–cohort models.ResultsOver the period, incidence of in situ melanoma increased in all age groups although the rates were lowest in those under 40 years of age. Incidence of invasive melanoma was either stable or decreased in people under 60, while it increased in those aged 60 and above, particularly in men. Age–period–cohort analysis revealed decreasing age-specific incidence of invasive melanoma under 40 years of age. Melanoma mortality over the period was stable or decreased in all groups except in men aged 60 or over. Overall, mortality rates generally declined or remained stable particularly in recent years.ConclusionIt is encouraging that rates of invasive melanoma are declining in the younger age cohorts – which could be attributed to both primary prevention efforts with individuals protecting their skin as well as early detection through self assessment and clinician performed skin checks. In addition, whilst it is important to monitor the increasing rates of in situ melanoma, the increase is likely due to early detection and treatment of melanoma that could have progressed to invasive melanoma and therefore detection whilst still in situ is an improved outcome. Overall, the results demonstrate the need to continue to improve the understanding of and compliance with primary skin cancer prevention measures in order to reduce population UVR exposure and overall melanoma incidence.     

Condition-dependent presence of beta-lipotropin-like peptide in human keratinocytes

This study aimed to characterize the beta-endorphin-immunoreactive material (betaE-IR) detectable in normal human keratinocytes (NHK). The effects of different culturing conditions and UV-irradiation on production of betaE-IR by NHK were assessed by radioimmunoassay and HPLC. All culture systems contained low levels of betaE-IR that was increased in conditioned media after UV-irradiation under certain conditions. NHK grown in nutrient-poor medium contained highest levels of betaE-IR that exhibited beta-lipotropin-like properties after HPLC analysis. The other culturing conditions displayed no authentic betaE-related peptides. Our results indicate that under certain culturing conditions NHK can produce POMC peptides like beta-lipotropin, which can be induced by UV-radiation.     

Making Decisions on the Resources for Cancer Control

We aim at modelling the strategic decision making process in case of devoting resources to a governmental cancer control program. We use a model based on the theory of Analytic Hierarchy Process. In this article we describe the characteristic features of such a decision making process and reveal the complexity of the problem underlying the decisions. A second article will present and discuss the results from the application of the AHP model. Interventions which are capable of decreasing the burden of cancer in a society need strategic approach. Decisions on interventions seem inevitable to be based on and balance between the priorities and the available resources. There is not much doubt about it that the reason for setting the priorities arises on the one hand from the scarcity of resources. On the other hand, priorities evolve on other bases, and are supposed to "guide" health policy makers devoting the scarce resources. In general, a strategic mode of thought has been based on assumptions, which, in case of cancer control enhance the necessity to assess information on cancer and cancer patients, and to understand the factors contributing towards better health. The capabilities of the NCCP achieving its aims by preventing the development of cancer diseases (primary prevention), by making use of the means of early detection and appropriate therapy (secondary prevention), and by providing modern (comprehensive) tertiary prevention are inevitably affected by the priorities. Health policy should assume a responsibility for enforcing certain priorities and should be aware of the long-term interest of the population. To solve the problem we restrict the model to a simple three level one, representing the goals, the criteria, and the alternatives of the resource allocation. We determine "decreasing the burden of cancer" as the overall goal. "Distributive justice" "cost-effectiveness", "human rights", "evidences", and "standpoints of a community" serve as criteria, while "primary prevention", "early detection and therapy, both belonging to the secondary prevention", "tertiary prevention", "research", and "education" form the alternatives.     

Cancer prevention in primary care. Current trends and some prospects for the future--II.

Cancer control encompasses the whole spectrum from prevention and early diagnosis to treatment and palliation. The key to the future of cancer control will be to establish multidisciplinary approaches to each type of cancer across this spectrum. For primary prevention this requires some understanding of the causes of each cancer. Although understanding of the aetiology of cancer has greatly improved, prospects for the primary prevention of many common cancers remain remote. Other approaches currently under evaluation include chemoprevention and the use of biomarkers (discussed last week). The identification of predisposing genes for some of the common cancers may have a considerable impact on the ability to recognise those at risk. Overall, however, mortality trends indicate that reduction of smoking remains the main priority for cancer prevention in the United Kingdom. For primary care teams, brief interventions to reduce smoking are likely to achieve the greatest benefit. This should be seen as part of broader policies aimed at achieving change in the whole population. The government must acknowledge its major responsibility to cancer prevention by banning all forms of advertising and promotion of tobacco.     

Pigmentation and Vitamin D Metabolism in Caucasians: Low Vitamin D Serum Levels in Fair Skin Types in the UK

Background

Vitamin D may play a protective role in many diseases. Public health messages are advocating sun avoidance to reduce skin cancer risk but the potential deleterious effects of these recommendations for vitamin D metabolism have been poorly investigated.

Methodology/Principal Findings

We investigated the association between 25-hydroxy-vitamin D (25(OH)D), skin type and ultraviolet exposure in 1414 Caucasian females in the UK. Mean age of the cohort was 47 years (18–79) and mean 25(OH)D levels were 77 nmol/L (6–289). 25(OH)D levels were strongly associated with season of sampling with higher levels in the spring and summer months (p<0.0001). Light skin types (skin type 1 and 2) have lower levels of 25(OH)D (mean 71 nmol/L) compared to darker skin types (skin type 3 and 4) (mean 82 nmol/L) after adjusting for multiple confounders (p<0.0001). The trend for increasing risk of low vitamin D with fairer skin types was highly significant despite adjustment for all confounders (p = 0.001).

Conclusions/Significance

Contrary to previous studies across different ethnic backgrounds, this study within Caucasian UK females shows that fair skin types have lower levels of 25(OH)D compared to darker skin types with potential detrimental health effects. Public health campaigns advocating sun avoidance in fair skinned individuals may need to be revised in view of their risk of vitamin D deficiency.     

Melanoma: prevention and early diagnosis.

Over the past two decades there has been a rapid rise in the numbers of people developing and dying from malignant melanoma. Sunlight is the main aetiological factor linked with melanoma. Exposure to the sun is a risk factor that can be modified provided that people are aware of the dangers. Health promotion campaigns can play a part in producing such change. General practitioners and practice nurses have an important part to play in providing those most at risk with information and advice about sensible sun exposure and sun protection measures. Campaigns to reduce delay in diagnosis by a combination of professional and public education have been reported from several centres around the world. The effects of these campaigns in reducing the depth distribution of cutaneous malignant melanoma have sometimes been encouraging, but in other instances have shown little effect. Until there is clear evidence that early detection reduces mortality from melanoma, the opportunistic promotion of early detection may not be cost effective and will fail to reach all sections of the community at risk. At the present time, therefore, the emphasis should be on the primary prevention of skin cancer.     

Decreased UV sensitivity, mismatch repair activity and abnormal cell cycle checkpoints in skin cancer cell lines derived from UVB-irradiated XPA-deficient mice

Xeroderma pigmentosum group A gene (XPA)-deficient mice are defective in nucleotide excision repair (NER) and are therefore highly sensitive to ultraviolet (UV)-induced skin carcinogenesis. We established cell lines from skin cancers of UVB-irradiated XPA-deficient mice to investigate the phenotypic changes occurring during skin carcinogenesis. As anticipated, the skin cancer cell lines were devoid of NER activity but were less sensitive to killing by UV-irradiation than the XPA(-/-) fibroblast cell line. The lines were also more resistant to 6-thioguanine (6-TG) than XPA(-/-) and XPA(+/+) fibroblasts, which was suggestive of a mismatch repair (MMR) defect. Indeed, in vitro mismatch binding and MMR activity were impaired in several of these cell lines. Moreover, these cell lines displayed cell cycle checkpoint derangements following UV-irradiation and 6-TG exposure. The above findings suggest that MMR downregulation may help cells escape killing by UVB, as was seen previously for methylating agents and cisplatin, and thus that MMR deficient clones are selected for during the tumorigenic transformation of XPA(-/-) cells.     

Characteristics of the biochemical manifestation of the process of thymic lymphocyte death following UV irradiation

Thymus lymphocyte death caused by UV-radiation is a function of radiation dose. Thymocyte death induced by UV-light, in contrast to gamma-radiation, is not accompanied by chromatin degradation. With UV-irradiation, irreparable DNA breaks are not responsible for thymocyte death. Cycloheximide, but not cysteamine, prevents the UV-induced cell death.     

Pigmentation and skin reaction to sun as risk factors for cutaneous melanoma: Western Canada Melanoma Study.

Between 1 April 1979 and 31 March 1981, 904 residents of the four western provinces of Canada (population 6.5 million), were diagnosed as suffering from primary cutaneous malignant melanoma. Of 801 patients aged 20-79 years, 665 (83%) were interviewed along with control subjects chosen at random from the general population and matched for age, sex, and province. After exclusion of 70 subjects with lentigo maligna or acral lentiginous melanoma, comparisons of the 595 case-control pairs showed that light hair, skin, and eye colour, a history of heavy freckling in adolescence, and a tendency to burn readily and tan poorly in the sun were significant risk factors for melanoma. The strongest primary associations were with blond hair (relative risk 7.1 compared with black hair), light colour of unexposed skin (relative risk 2.4), and severe freckling (relative risk 2.1). These associations were independent of ethnic origin and of recorded amount of exposure to the sun and were somewhat stronger for superficial spreading than for nodular melanoma. This study is the largest and most detailed of an incident series of melanomas to be published to date. The results were consistent with other studies reporting associations between melanoma and poor tanning ability, a tendency to burn easily, and a history of sunburn and showed that light hair colour was the strongest risk factor for the disease.     

Impaired nucleotide excision repair pathway as a possible factor in pathogenesis of head and neck cancer

Tobacco smoking is one of the major risk factors in pathogenesis of head and neck squamous cell carcinomas (HNSCC). Many of the chemical compounds present in tobacco are well-known carcinogens which form adducts with DNA. Cells remove these adducts mainly by the nucleotide excision repair pathway (NER). NER also eliminates a broad spectrum of pyrimidine dimers (CPD) and photo-products (6-4PP) induced by UV-radiation or DNA cross-links after cisplatin anti-cancer treatment. In this study DNA damage and repair was examined in peripheral blood lymphocytes obtained from 20 HNSCC patients and 20 healthy controls as well as HTB-43 larynx and SSC-25 tongue cancer cell lines. DNA repair kinetics in the examined cells after cisplatin or UV-radiation treatment were investigated using alkaline comet assay during 240min of post-treatment incubation. MTT assay was used to analyse cell viability and the Annexin V-FITC kit specific for kinase-3 was employed to determine apoptosis after treating the cells with UV-radiation at dose range from 0.5 to 60J/m(2). NER capability was assessed in vitro with cell extracts by the use of a bacterial plasmid irradiated with UV-light as a substrate for the repair. The results show that lymphocytes from HNSCC patients and HTB-43 or SSC-25 cancer cells were more sensitive to genotoxic treatment with UV-radiation and displayed impaired DNA repair. Also evidenced was a higher rate of apoptosis induction after UV-radiation treatment of lymphocytes from the HNSCC patients and the HTB-43 cancer cells than after treatment of those from healthy donors. Finally, our results showed that there was a significant decrease in NER capacity in HTB-43 or SSC-25 cancer cells as well as in peripheral blood lymphocytes of HNSCC patients compared to controls. In conclusion, we suggest that the impaired NER pathway might be a critical factor in pathogenesis of head and neck cancer.     

Benefit Cost Analysis of Three Skin Cancer Public Education Mass-Media Campaigns Implemented in New South Wales,Australia

Public education mass media campaigns are an important intervention for influencing behaviour modifications. However, evidence on the effectiveness of such campaigns to encourage the population to reduce sun exposure is limited. This study investigates the benefits and costs of three skin cancer campaigns implemented in New South Wales from 2006–2013. This analysis uses Australian dollars (AUD) and 2010–11 as the currency and base year, respectively. Historical data on skin cancer were used to project skin cancer rates for the period 2006–2020. The expected number of skin cancer cases is derived by combining skin cancer rates, sunburn rates and relative risk of skin cancers due to sun exposure. Counterfactual estimates are based on sunburn exposure in the absence of the campaigns. Monetary values are attached to direct (treatment) and indirect (productivity) costs saved due to fewer skin cancer cases. Monetary benefits are compared with the cost of implementing the campaigns and are presented in the form of a benefit-cost ratio. Relative to the counterfactual (i.e., no campaigns) there are an estimated 13,174 fewer skin cancers and 112 averted deaths over the period 2006–2013. The net present value of these benefits is $60.17 million and the campaign cost is $15.63 million. The benefit cost ratio is 3.85, suggesting that for every $1 invested a return of $3.85 is achieved. Skin cancer public education mass media campaigns are a good investment given the likely extent to which they reduce the morbidity, mortality and economic burden of skin cancer.     

Skin cancer--primary and secondary prevention (information campaigns and screening)--with a focus on children & sunbeds

Solar and artificial (sunbed) UV-exposure is the main risk factor for the development of epithelial skin cancer (basal cell carcinoma, BCC, and squamous cell carcinoma, SCC) as well for malignant melanoma (MM). UV exposure in childhood and adolescence is especially important. Therefore, adequate methods of primary prevention have continuously to be used and to be developed further to target these age-groups in order to reduce the risks of intensive UV-exposure. Primary prevention can effectively be combined with secondary prevention (early detection, screening) to reduce the burden of skin cancer and to decrease incidence, morbidity and mortality.     

Raccoons (Procyon lotor) in Germany as potential reservoir species for Lyssaviruses

Raccoons can be found almost everywhere in Germany since their first successful introduction in 1934. Although the animal is a well-known reservoir species for rabies in the USA, during the last European fox rabies epizootic, only a few rabid raccoons were reported from Germany. In recent years, the raccoon population density has increased tremendously, especially in (semi) urban settings. Presently, Germany is free of terrestrial wildlife rabies. To assess the potential risk that the raccoon population in Germany could act as a reservoir species upon reemergence of rabies, the susceptibility of the local raccoon population was investigated. Wild-caught animals were inoculated with the most likely lyssavirus variants to infect the local population. It was shown that the raccoons were fully susceptible for a dog and raccoon rabies virus isolate. Also, five of six raccoons inoculated with a fox rabies virus isolate showed clinical signs. However, none of the raccoons infected with European Bat Lyssavirus type 1 succumbed to rabies; meanwhile, all these raccoons seroconverted. It is concluded that the highest risk for the raccoon population in Germany to become infected with lyssaviruses is through the importation of rabies infected dogs.     

Deprivation and emergency admissions for cancers of colorectum,lung, and breast in south east England: ecological study

Objectives: To examine the relation between deprivation and acute emergency admissions for cancers of the colon, rectum, lung, and breast in south east England. Design: Ecological analysis with data from hospital episode statistics and 1991 census. Setting: North and South Thames Regional Health Authorities (population about 14 million), divided into 10 aggregations of 31 470 census enumeration districts (median population 462). Subjects: 146 639 admissions relating to 76 552 patients aged <100 years on admission, resident in the Thames regions, admitted between 1 April 1992 and 31 March 1995. Results: Residents living in deprived areas were more likely to be admitted as emergencies and has ordinary inpatient admissions and less likely to be admitted as day cases. Adjusted odds of ordinary admissions from the most deprived tenth occurring as emergencies (relative to admissions from the most affluent tenth) were 2.29 (95% confidence interval 2.09 to 2.52) for colorectal cancer, 2.20 (1.99 to 2.43) for lung cancer, and 2.41 (2.17 to 2.67) for female breast cancer; adjusted odds of admissions as day cases were 0.70 (0.64 to 0.76), 0.50 (0.44 to 0.56), and 0.56 (0.50 to 0.62), respectively. Patients from deprived areas with lung or breast cancers were less likely to be recorded as having surgical interventions. Adjusted odds of patients from the most deprived tenth receiving surgery were 0.88 (0.78 to 1.00), 0.58 (0.48 to 0.70), and 0.63 (0.56 to 0.71), respectively. Admissions for colorectal cancer from the most deprived areas were less likely to be to hospitals admitting 100 or more new patients a year; the opposite held true for breast cancer admissions. No association was found for lung cancer admissions. Conclusions: Earlier diagnostic and referral procedures in primary care in deprived areas are required if there are to be significant reductions in mortality from these cancers. A national information strategy is required to ensure the continued availability of population based data on NHS patients and to mandate standardised datasets from the private sector. Rationalisation of acute services, hospital mergers, and plans for bed closures must take into account the increased healthcare needs and inequities in access to treatment and care of residents in areas with high levels of deprivation. Health authorities and primary care groups should re-examine their purchasing intentions, service reviews, and monitoring arrangements in the light of these findings.

Key messages

• A major reorganisation of cancer services is under way in England and Wales with the aim of improving access to and quality of treatment
• Residents with cancers of the bowel, lung, or breast in deprived areas in the Thames region were more likely to be admitted as emergencies and ordinary inpatients than their counterparts from more affluent areas, and patients with lung or breast cancers from deprived areas were less likely to receive surgical treatment
• Patients with colorectal cancer from the most deprived areas were less likely to be seen at hospitals with a large caseload than were patients from affluent areas; the opposite held true for patients with breast cancer, but no association was found for admissions for lung cancer
• More effective early diagnostic and referral procedures in primary care in deprived areas are required if reductions in mortality are to be achieved
• Hospital mergers and plans for service reconfiguration and bed closures must take into account inequities in access to treatment among residents in deprived areas