Long-term increase in sunscreen use in an Australian community after a skin cancer prevention trial

Cost-effectiveness analysis and return on investment of SunSmart Western Australia to prevent skin cancer

Each year, malignant melanoma accounts for 57 000 deaths globally. If current rates continue, there will be an estimated 510 000 new cases annually and 96 000 deaths by 2040. Melanoma and keratinocyte cancers (KCs) incur a large societal burden. Using a mathematical population model, we performed an economic evaluation of the SunSmart program in the state of Western Australia (WA), a primary prevention program to reduce the incidence of skin cancer, versus no program. A societal perspective was taken combining costs to the health system, patients and lost productivity. The model combined data from pragmatic trial evidence of sun protection, epidemiological studies and national cost reports. The main outcomes modelled were societal and government costs, skin cancer counts, melanoma deaths, life years and quality-adjusted life years. Over the next 20 years, the model predicted that implementing the WA SunSmart program would prevent 13 728 KCs, 636 melanomas and 46 melanoma deaths per 100 000 population. Furthermore, 251 life years would be saved, 358 quality-adjusted life years gained and AU$2.95 million in cost savings to society per 100 000 population would be achieved. Key drivers of the model were the rate reduction of benign lesions from sunscreen use, the costs of purchasing sunscreen and the effectiveness of reducing KCs in sunscreen users. The likelihood of WA SunSmart being cost-effective was 90.1%. For the WA Government, the estimated return on investment was $8.70 gained for every $1 invested. Primary prevention of skin cancer is a cost-effective strategy for preventing skin cancers.

Cancer awareness in Australian adolescents

BACKGROUND

Over one-third of cancer cases are attributable to modifiable risk factors. Because health-related behaviors are often established at adolescence, it is important that adolescents understand the risks and lifestyle decisions that may reduce their chances of developing cancer. This study aims to identify the levels of cancer awareness of adolescents in Australia.

METHODS

Paper questionnaires were used to collect information about baseline levels of cancer awareness. These questionnaires included socio-demographic questions and the Cancer Awareness Measure (CAM) with slight modifications to ensure their suitability for the Australian adolescent population. Students aged 11 to 19 years were recruited from 13 Australian high schools between 2016 and 2019.

RESULTS

A total of 766 adolescents (58% female, mean age = 14.5 years) completed the questionnaires. Adolescents' cancer awareness was low. Adolescents who knew someone with cancer recognized significantly more cancer risk factors and cancer warning signs than those who did not know someone with cancer (t (756) = 2.35, p = .019; t (747) = 5.57, p = .001). Those from high Index of Community Socio-Educational Advantage (ICSEA) schools significantly recognized more cancer risk factors than those from low ICSEA schools (t (764) = 2.42, p = .016). Females recognized significantly more warning signs than males (t (583) = 3.11, p = .002) and students from senior high school grades recognized more warning signs than those from junior grades (t (754) = 2.24, p = .02). Most adolescents (78%) were aware of skin cancer as one of the most common cancers in Australia, however half or less were aware of other common cancers. Although most adolescents would seek medical help in the presence of possible cancer symptoms as soon as possible, approximately 20% of them would not see a doctor promptly. Emotional barriers were the most common reasons to delay seeing a doctor (56%), for example "being worried about hearing bad news" (27%).

CONCLUSIONS

Australian adolescents show poor awareness of cancer risk factors and cancer warning signs. A number of demographic and experience factors were found to be related to lower cancer awareness. Education is essential to raise cancer awareness, promote healthy lifestyles from adolescence and avoid a preventable cancer diagnosis.

The effects of exposure to solar radiation on human health

This assessment by the Environmental Effects Assessment Panel (EEAP) of the Montreal Protocol under the United Nations Environment Programme (UNEP) evaluates the effects of ultraviolet (UV) radiation on human health within the context of the Montreal Protocol and its Amendments. We assess work published since our last comprehensive assessment in 2018. Over the last four years gains have been made in knowledge of the links between sun exposure and health outcomes, mechanisms, and estimates of disease burden, including economic impacts. Of particular note, there is new information about the way in which exposure to UV radiation modulates the immune system, causing both harms and benefits for health. The burden of skin cancer remains high, with many lives lost to melanoma and many more people treated for keratinocyte cancer, but it has been estimated that the Montreal Protocol will prevent 11 million cases of melanoma and 432 million cases of keratinocyte cancer that would otherwise have occurred in the United States in people born between 1890 and 2100. While the incidence of skin cancer continues to rise, rates have stabilised in younger populations in some countries. Mortality has also plateaued, partly due to the use of systemic therapies for advanced disease. However, these therapies are very expensive, contributing to the extremely high economic burden of skin cancer, and emphasising the importance and comparative cost-effectiveness of prevention. Photodermatoses, inflammatory skin conditions induced by exposure to UV radiation, can have a marked detrimental impact on the quality of life of sufferers. More information is emerging about their potential link with commonly used drugs, particularly anti-hypertensives. The eyes are also harmed by over-exposure to UV radiation. The incidence of cataract and pterygium is continuing to rise, and there is now evidence of a link between intraocular melanoma and sun exposure. It has been estimated that the Montreal Protocol will prevent 63 million cases of cataract that would otherwise have occurred in the United States in people born between 1890 and 2100. Despite the clearly established harms, exposure to UV radiation also has benefits for human health. While the best recognised benefit is production of vitamin D, beneficial effects mediated by factors other than vitamin D are emerging. For both sun exposure and vitamin D, there is increasingly convincing evidence of a positive role in diseases related to immune function, including both autoimmune diseases and infection. With its influence on the intensity of UV radiation and global warming, the Montreal Protocol has, and will have, both direct and indirect effects on human health, potentially changing the balance of the risks and benefits of spending time outdoors.

Prevention versus early detection for long-term control of melanoma and keratinocyte carcinomas: a cost-effectiveness modelling study

OBJECTIVE

To compare the long-term economic impact of melanoma prevention by sun protection, with the corresponding impact of early detection of melanoma to decrease melanoma deaths.

DESIGN

Cost-effectiveness analysis using Markov cohort model. Data were primarily from two population-based randomised controlled trials, epidemiological and costing reports, and included flow-on effects for keratinocyte cancers (previously non-melanoma skin cancers) and actinic keratoses.

SETTING

Queensland, Australia.

PARTICIPANTS

Men and women with a mean age 50 years modelled for 30 years.

INTERVENTIONS

Daily sunscreen use (prevention) compared with annual clinical skin examinations (early detection) and comparing these in turn with the status quo.

PRIMARY AND SECONDARY OUTCOMES

Costs, counts of melanoma, melanoma deaths, keratinocyte cancers, life years and quality-adjusted life years.

RESULTS

Per 100 000 individuals, for early detection, primary prevention and without intervention, there were 2446, 1364 and 2419 new melanomas, 556, 341 and 567 melanoma deaths, 64 452, 47 682 and 64 659 keratinocyte cancers and £493.5, £386.4 and £406.1 million in economic costs, respectively. There were small differences between prevention and early detection in life years saved (0.09%) and quality-adjusted life years gained (0.10%).

CONCLUSIONS

Compared with early detection of melanoma, systematic sunscreen use at a population level will prevent substantial numbers of new skin tumours, melanoma deaths and save healthcare costs. Primary prevention through daily use of sunscreen is a priority for investment in the control of melanoma.

Regular Sunscreen Use and Risk of Mortality: Long-Term Follow-up of a Skin Cancer Prevention Trial

INTRODUCTION

Sunscreen is widely used to protect the skin from harmful effects of sun exposure. However, there are concerns that sunscreens may negatively affect overall health. Evidence of the general safety of long-term regular sunscreen use is therefore needed.

METHODS

The effect of long-term sunscreen use on mortality was assessed over a 21-year period (1993-2014) among 1,621 Australian adults who had participated in a randomized skin cancer prevention trial of regular versus discretionary sunscreen use (1992-1996). In 2018, an intention-to-treat analysis was conducted using Cox proportional hazards regression to compare death rates in people who were randomized to apply sunscreen daily for 4.5years, versus randomized to use sunscreen at their usual, discretionary level. All-cause mortality and deaths resulting from cardiovascular disease, cancer, and other causes were considered.

RESULTS

In total, 160 deaths occurred in the daily sunscreen group compared with 170 deaths in the discretionary sunscreen group (hazard ratio=0.94, 95% CI=0.76, 1.17); 59vs 76 cardiovascular disease deaths (hazard ratio=0.77, 95% CI=0.55, 1.08), 63vs 58 cancer deaths (hazard ratio=1.09, 95% CI=0.76, 1.57), and 45vs 44 deaths resulting from other causes (hazard ratio=1.02, 95% CI=0.67, 1.54) occurred respectively.

CONCLUSIONS

Regular use of a sun protection factor 16 sunscreen on head, neck, arms, and hands for 4.5years did not increase mortality.

Sun protection for preventing basal cell and squamous cell skin cancers

BACKGROUND

'Keratinocyte cancer' is now the preferred term for the most commonly identified skin cancers basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), which were previously commonly categorised as non-melanoma skin cancers (NMSC). Keratinocyte cancer (KC) represents about 95% of malignant skin tumours. Lifestyle changes have led to increased exposure to the sun, which has, in turn, led to a significant increase of new cases of KC, with a worldwide annual incidence of between 3% and 8%. The successful use of preventive measures could mean a significant reduction in the resources used by health systems, compared with the high cost of the treatment of these conditions. At present, there is no information about the quality of the evidence for the use of these sun protection strategies with an assessment of their benefits and risks.

OBJECTIVES

To assess the effects of sun protection strategies (i.e. sunscreen and barrier methods) for preventing keratinocyte cancer (that is, basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) of the skin) in the general population.

SEARCH METHODS

We searched the following databases up to May 2016: the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS. We also searched five trial registries and the bibliographies of included studies for further references to relevant trials.

SELECTION CRITERIA

We included randomised controlled clinical trials (RCTs) of preventive strategies for keratinocyte cancer, such as physical barriers and sunscreens, in the general population (children and adults), which may provide information about benefits and adverse events related to the use of solar protection measures. We did not include trials focused on educational strategies to prevent KC or preventive strategies in high-risk groups. Our prespecified primary outcomes were BCC or cSCC confirmed clinically or by histopathology at any follow-up and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for eligibility using Early Review Organizing Software (EROS). Similarly, two review authors independently used predesigned data collection forms to extract information from the original study reports about the participants, methods of randomisation, blinding, comparisons of interest, number of participants originally randomised by arm, follow-up losses, and outcomes, and they assessed the risk of bias. We resolved any disagreement by consulting a third author and contacted trial investigators of identified trials to obtain additional information. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included one RCT (factorial design) that randomised 1621 participants.This study compared the daily application of sunscreen compared with discretionary use of sunscreen, with or without beta-carotene administration, in the general population. The study was undertaken in Australia; 55.2% of participants had fair skin, and they were monitored for 4.5 years for new cases of BCC or cSCC assessed by histopathology. We found this study to be at low risk of bias for domains such as allocation, blinding, and incomplete outcome data. However, we found multiple unclear risks related to other biases, including an unclear assessment of possible interactions between the effects of the different interventions evaluated (that is, sunscreen and beta-carotene). We found no difference in terms of the number of participants developing BCC (n = 1621; risk ratio (RR) 1.03, 95% confidence interval (CI) 0.74 to 1.43) or cSCC (n = 1621; RR 0.88, 95% CI 0.50 to 1.54) when comparing daily application of sunscreen with discretionary use, even when analyses were restricted to groups without beta-carotene supplementation. This evidence was of low quality, which means that there is some certainty that future studies may alter our confidence in this evidence.We reported adverse events in a narrative way and included skin irritation or contact allergy.We identified no studies that evaluated other sun protection measures, such as the use of sun-protective clothing, sunglasses, or hats, or seeking the shade when outdoors.

AUTHORS' CONCLUSIONS

In this review, we assessed the effect of solar protection in preventing the occurrence of new cases of keratinocyte cancer. We only found one study that was suitable for inclusion. This was a study of sunscreens, so we were unable to assess any other forms of sun protection. The study addressed our prespecified primary outcomes, but not most of our secondary outcomes. We were unable to demonstrate from the available evidence whether sunscreen was effective for the prevention of basal cell carcinoma (BCC) or cutaneous squamous cell carcinoma (cSCC).Our certainty in the evidence was low because there was a lack of histopathological confirmation of BCC or cSCC in a significant percentage of cases. Amongst other sources of bias, it was not clear whether the study authors had assessed any interaction effects between the sunscreen and beta-carotene interventions. We think that further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.

Melanoma risk in relation to use of sunscreen or other sun protection methods

BACKGROUND

Epidemiologic evidence supporting sunscreen for melanoma prevention is limited to one small trial; case-control studies report conflicting results. Sunscreen usage patterns or alternative sun protection methods have rarely been studied in relation to melanoma.

METHODS

In a population-based case-control study, participants (1,167 cases; 1,101 controls) reported for each decade year of age outdoor activity-related sunscreen use, sunscreen patterns (SPF15+, amount, skin coverage, reapplication, routine use), and use of other sun protection methods (like hats, long-sleeved shirts, staying in the shade). Scores were averaged across activities and/or decades; scores in the most recent two decades were used to classify individuals as non-, inconsistent- or optimal users. Adjusted mean score differences between cases and controls, and ORs and 95% CIs for melanoma among optimal-, inconsistent- versus nonusers were calculated.

RESULTS

Mean scores for sunscreen, sunscreen patterns or other sun protection methods were low, but higher among controls than cases for SPF15+ sunscreen (P = 0.03) and other sun protection methods (P = 0.006). Adjusted ORs for optimal use of sunscreen and most sunscreen patterns were null or relatively weak, except for routine sunscreen (adjusted OR = 0.44, 95% CI: 0.23-0.86). Optimal use of other sun protection methods was inversely associated with melanoma (adjusted OR = 0.59, 95% CI: 0.44-0.78).

CONCLUSIONS

Optimal use of routine sunscreen or other sun protection methods were most strongly associated with decreased melanoma risk; results are limited by the small number of subjects who used sunscreen routinely and lack of specificity regarding other sun protection methods.

IMPACT

Both improving sunscreen practices and encouraging sun avoidance strategies may be important for melanoma prevention.

Sun protection advice mediated by the general practitioner: an effective way to achieve long-term change of behaviour and attitudes related to sun exposure?

OBJECTIVE

To investigate, in primary health care, differentiated levels of prevention directed at skin cancer, and how the propensity of the patients to change sun habits/sun protection behaviour and attitudes towards sunbathing were affected, three years after intervention. Additionally, the impact of the performance of a phototest as a complementary tool for prevention was evaluated.

DESIGN

Randomized controlled study. Setting and subjects. During three weeks in February, all patients ≥ 18 years of age registering at a primary health care centre in southern Sweden were asked to fill in a questionnaire mapping sun exposure habits, attitudes towards sunbathing, and readiness to increase sun protection according to the Transtheoretical Model of Behaviour Change (TTM) (n = 316). They were randomized into three intervention groups, for which sun protection advice was given, in Group 1 by means of a letter, and in Groups 2 and 3 orally during a personal GP consultation. Group 3 also underwent a phototest to demonstrate individual skin UV sensitivity.

MAIN OUTCOME MEASURES

Change of sun habits/sun protection behaviour and attitudes, measured by five-point Likert scale scores and readiness to increase sun protection according to the TTM, three years after intervention, by a repeated questionnaire.

RESULTS

In the letter group, almost no improvement in sun protection occurred. In the two doctor's consultation groups, significantly increased sun protection was demonstrated for several items, but the difference compared with the letter group was significant only for sunscreen use. The performance of a phototest did not appear to reinforce the impact of intervention.

CONCLUSION

Sun protection advice, mediated personally by the GP during a doctor's consultation, can lead to improvement in sun protection over a prolonged time period.

Trends in Hospital Admissions for Sunburn in Western Australia, 1988 to 2008

The objective of this study was to assess the trends in hospitalization for sunburn in Western Australia from 1988 to 2008. De-identified linked hospital morbidity data for all index sunburn admissions in Western Australia for the period 1988 to 2008 were analyzed. Poisson regression analysis was used to estimate trends in hospital admissions. Hospitalizations increased from 1.6 (95% confidence interval [CI] = 1.0-2.2) per 100 000 person years in 1988 to 2.7 (95% CI = 1.9-3.4) per 100 000 person years in 1997, declining thereafter to 1.5 (95% CI = 1.0-2.0) per 100 000 person years in 2008. Increased hospitalizations rates were estimated for adults 25 to 44 years and 65 years or older, with a significant decline estimated for children younger than 5 years; rates remained stable for all other age groups. This study found no significant overall reduction in sunburn hospitalizations over the 20-year study period. Results raise concerns about the sun-protective behaviors and skin cancer risk of the population in Western Australia.

Reduced melanoma after regular sunscreen use: randomized trial follow-up

PURPOSE

Regular sunscreen use prevents cutaneous squamous cell carcinoma long term, but the effect on melanoma is highly controversial. We evaluated whether long-term application of sunscreen decreases risk of cutaneous melanoma.

PARTICIPANTS AND METHODS

In 1992, 1,621 randomly selected residents of Nambour, a township in Queensland, Australia, age 25 to 75 years, were randomly assigned to daily or discretionary sunscreen application to head and arms in combination with 30 mg beta carotene or placebo supplements until 1996. Participants were observed until 2006 with questionnaires and/or through pathology laboratories and the cancer registry to ascertain primary melanoma occurrence.

RESULTS

Ten years after trial cessation, 11 new primary melanomas had been identified in the daily sunscreen group, and 22 had been identified in the discretionary group, which represented a reduction of the observed rate in those randomly assigned to daily sunscreen use (hazard ratio [HR], 0.50; 95% CI, 0.24 to 1.02; P = .051). The reduction in invasive melanomas was substantial (n = 3 in active v 11 in control group; HR, 0.27; 95% CI, 0.08 to 0.97) compared with that for preinvasive melanomas (HR, 0.73; 95% CI, 0.29 to 1.81).

CONCLUSION

Melanoma may be preventable by regular sunscreen use in adults.

Targeting ornithine decarboxylase for the prevention of nonmelanoma skin cancer in humans

Bailey et al. report in this issue of the journal (beginning on page 35) one of the first successful trials of basal cell carcinoma (BCC) prevention. Oral alpha-difluoromethyl-dl-ornithine (DFMO) reduced new BCCs in patients with a prior history of nonmelanoma skin cancer. DFMO is an inhibitor of ornithine decarboxylase, a key enzyme in the polyamine biosynthetic pathway. This perspective on Bailey et al. discusses our knowledge of the contribution of polyamines to BCC pathogenesis, how this knowledge advanced the development of a new method to prevent BCCs, and prospects for future studies of DFMO in BCC prevention.

Knowledge, attitudes, and behaviors of elementary school students regarding sun exposure and skin cancer

The aim of this study was to assess baseline knowledge of skin cancer, sun protection practices, and perceptions of tanning among third through fifth grade elementary students in Florida. A total of 4,002 students in nineteen elementary schools in Palm Beach County, Florida were surveyed. SunSmart America curriculum pretest responses were the main outcome measures. Overall students' knowledge using a students' mean knowledge scale scores of skin cancer and sun protection were low (<40% of questions answered correctly) and was found to increase with increasing grade level (p < 0.01). Boys more frequently reported spending greater than 2 hours in the sun when compared with girls (p < 0.01). Girls, however, were more likely to try and get a tan most of the time or always when compared with boys (p = 0.02). Non-Hispanic White students (51.3%) more frequently reported use of SPF 15 or greater sunscreen "most of the time or always" compared with Hispanic (35.3%) and non-Hispanic Black (13.4%) students (p < 0.01). Elementary aged students in south Florida have limited knowledge about sun safety, despite spending considerable amount of time in the sun. Sun safe behavior is associated with gender and ethnicity. The findings provide empirical support for the need of a school-based educational intervention.

Incidence of basal cell carcinoma multiplicity and detailed anatomic distribution: longitudinal study of an Australian population

A proportion of individuals are affected multiple times by basal cell carcinoma (BCC), but the rate and extent to which this occurs is unknown. We therefore prospectively estimated BCC incidence in a subtropical Australian population, focusing on the rate at which persons develop multiple primary BCCs and the precise anatomic sites of BCC occurrence. Between 1997 and 2006, 663 BCCs were confirmed in 301 of 1,337 participants in the population-based Nambour Skin Cancer Study. The incidence of persons affected multiple times by primary BCC was 705 per 100,000 person years compared to an incidence rate of people singly affected of 935 per 100,000 person years. Among the multiply and singly affected alike, site-specific BCC incidence rates were far highest on facial subsites, followed by upper limbs, trunk, and then lower limbs. We conclude that actual BCC tumor burden is much greater in the population than is apparent from normal incidence rates. Anatomic distribution of BCC is consistent with general levels of sun exposure across body sites.

Prolonged Prevention of Squamous Cell Carcinoma of the Skin by Regular Sunscreen Use

Half of all cancers in the United States are skin cancers. We have previously shown in a 4.5-year randomized controlled trial in an Australian community that squamous cell carcinomas (SCC) but not basal cell carcinomas (BCC) can be prevented by regular sunscreen application to the head, neck, hands, and forearms. Since cessation of the trial, we have followed participants for a further 8 years to evaluate possible latency of preventive effect on BCCs and SCCs. After prolonged follow-up, BCC tumor rates tended to decrease but not significantly in people formerly randomized to daily sunscreen use compared with those not applying sunscreen daily. By contrast, corresponding SCC tumor rates were significantly decreased by almost 40% during the entire follow-up period (rate ratio, 0.62; 95% confidence interval, 0.38-0.99). Regular application of sunscreen has prolonged preventive effects on SCC but with no clear benefit in reducing BCC.