Robin Marks

Reduction of Solar Keratoses by Regular Sunscreen Use

BACKGROUND The incidence of and mortality from skin cancer are increasing in many countries. In view of the added concern about ozone depletion, many organizations are promoting the regular use of sunscreens to prevent skin cancer, despite the absence of evidence that these products have this effect. Solar (actinic) keratosis is a precursor of squamous-cell carcinoma of the skin. METHODS We conducted a randomized, controlled trial of the effect on solar keratoses of daily use of a broad-spectrum sunscreen cream with a sun-protection factor of 17 in 588 people 40 years of age or older in Australia during one summer (September 1991 to March 1992). The subjects applied either a sunscreen cream or the base cream minus the active ingredients of the sunscreen to the head, neck, forearms, and hands. RESULTS The mean number of solar keratoses increased by 1.0 per subject in the base-cream group and decreased by 0.6 in the sunscreen group (difference, 1.53; 95 percent confidence interval, 0.81 to 2.25). The sunscreen group had fewer new lesions (rate ratio, 0.62; 95 percent confidence interval, 0.54 to 0.71) and more remissions (odds ratio, 1.53; 95 percent confidence interval, 1.29 to 1.80) than the base-cream group. There was a dose-response relation: the amount of sunscreen cream used was related to both the development of new lesions and the remission of existing ones. CONCLUSIONS Regular use of sunscreens prevents the development of solar keratoses and, by implication, possibly reduces the risk of skin cancer in the long-term.

MALIGNANT TRANSFORMATION OF SOLAR KERATOSES TO SQUAMOUS CELL CARCINOMA

1689 people aged 40 years and over were examined over a 5-year period to determine the incidence of malignant transformation of solar keratoses. They were seen on 2 consecutive years on 4267 occasions; a total of 21,905 solar keratoses were present on the first visit. A squamous cell carcinoma (SCC) developed within 12 months on 28 of the 4267 occasions. Where accurate mapping of both SCCs and pre-existing solar keratoses was available, it was found that 10/17 (60%) SCCs arose from a lesion diagnosed clinically as a solar keratosis in the previous year and the other 7 (40%) SCCs on what had been clinically normal skin 12 months previously. The risk of malignant transformation of a solar keratosis to SCC within 1 year was less than 1/1000. The cost-effectiveness of treating all solar keratoses to prevent the development of SCC is questionable.

Incidence of non-melanocytic skin cancer treated in Australia

In 1985, as part of a national random household omnibus survey by a market research company, 30 976 Australians (mostly of European origin) were asked whether they had ever been treated by a doctor for skin cancer. The treating doctor or hospital was then approached for confirmation of the diagnosis of all those people who claimed to have been so treated within the past 12 months. Demographic data were also collected, permitting analysis by age, sex, country of birth, current residence, and skin reaction to strong sunlight. Melanomas accounted for less than 5% of the tumours treated. The world standardised incidence of melanoma was 19/100 000 population. The standardised incidence of treated non-melanocytic skin cancer in Australia was estimated to be 823/100 000. The standardised rates for basal cell carcinoma and squamous cell carcinoma were 657 and 166/100 000 respectively, yielding a standardised rate ratio of about 4:1. Standardised rates based on medically confirmed cases only were 555, 443, and 112/100 000 for all non-melanocytic skin cancers, basal cell carcinomas, and squamous cell carcinomas respectively. Significant differences and trends in incidence were noted with respect to age and sex. Rates in men were higher than those in women but significantly so only after the age of 60. People born in Australia had a rate of 936/100 000 compared with 402/100 000 in British migrants. Rates for non-melanocytic skin cancer showed a gradient with respect to latitude within Australia. The rate in people residing north of 29°S was 1242/100 000 compared with a rate of 489/100 000 in those living south of 37°S. A persons skin reaction to strong sunlight was a good indicator of the risk of skin cancer, tanning ability being inversely related to its incidence. The rate in those who always burnt and never tanned when exposed to strong sunlight was 1764/100 000 compared with a rate of 616/100 000 in those who always tanned and never burnt. These findings have important implications for public education programmes in relation to exposure to sunlight in Australia.

An overview of skin cancers

The incidence and mortality rates of skin cancer are rising in the United States and in many other countries. Concerns about stratospheric ozone depletion adding to the problem have made many organizations look at public and professional health programs as a possible solution. Early detection can reduce the problem in the short term, because mortality due to melanoma is clearly related to the depth of invasion of the tumor when it is removed. This is the factor which is amenable to change in an education program on early detection. Exposure to sunlight is clearly related to risk of development of skin cancer, including both melanoma and nonmelanoma skin cancers. This is the component of the equation of constitutional predisposition plus exposure to environmental risk factors leading to skin cancer that is amenable to change as a result of educational programs. On the basis of available data, there is a case for further development, provision, and evaluation of public and professional education programs designed to control what is becoming a major public health problem in the community. Cancer 1995;75:607-612.The incidence and mortality rates of skin cancer are rising in the United States and in many other countries. Concerns about stratospheric ozone depletion adding to the problem have made many organizations look at public and professional health programs as a possible solution.

The Global Burden of Skin Disease in 2010: An Analysis of the Prevalence and Impact of Skin Conditions

The Global Burden of Disease (GBD) Study 2010 estimated the GBD attributable to 15 categories of skin disease from 1990 to 2010 for 187 countries. For each of the following diseases, we performed systematic literature reviews and analyzed resulting data: eczema, psoriasis, acne vulgaris, pruritus, alopecia areata, decubitus ulcer, urticaria, scabies, fungal skin diseases, impetigo, abscess, and other bacterial skin diseases, cellulitis, viral warts, molluscum contagiosum, and non-melanoma skin cancer. We used disability estimates to determine nonfatal burden. Three skin conditions, fungal skin diseases, other skin and subcutaneous diseases, and acne were in the top 10 most prevalent diseases worldwide in 2010, and eight fell into the top 50; these additional five skin problems were pruritus, eczema, impetigo, scabies, and molluscum contagiosum. Collectively, skin conditions ranged from the 2nd to 11th leading cause of years lived with disability at the country level. At the global level, skin conditions were the fourth leading cause of nonfatal disease burden. Using more data than has been used previously, the burden due to these diseases is enormous in both high- and low-income countries. These results argue strongly to include skin disease prevention and treatment in future global health strategies as a matter of urgency.

Trends in the incidence of non-melanocytic skin cancer (NMSC) treated in Australia 1985–1995: Are primary prevention programs starting to have an effect?

Non‐melanocytic skin cancer (NMSC) is the most common cancer in Australia, but data on its incidence are not routinely collected by cancer registries. National surveys were conducted in 1985, 1990 and 1995 to estimate NMSC incidence. Trends in incidence between 1985 and 1995 have been examined to determine the impact of primary prevention campaigns aimed at controlling skin cancer in Australia. National random household surveys of Australians aged over 13 years were used to estimate NMSC incidence in 1985, 1990 and 1995. Age‐ and sex‐specific rates by survey year were modelled using Poisson regression. Basal cell carcinoma (BCC) rates in 1995 were 788 per 100,000, an increase of 19% since 1985. Squamous cell carcinoma (SCC) rates rose by 93% over the same period, from 166 to 321 per 100,000. The ratio of BCC:SCC changed from 4:1 in 1985 to 2.5:1 in 1995. BCC rates in latitudes <29°S remained at about 3 times those in latitudes >37°S over the decade. The ratio of SCC incidence between these latitudes changed from around 7:1 to 3:1 over the same period. Although NMSC incidence rates continue to rise, there have been reductions in BCC observed in younger age groups. Incidence rates of NMSC continue to rise in Australia, but there is evidence of a reduction in BCC incidence in younger cohorts. This is evidence that public health campaigns to reduce sun exposure may be having a beneficial effect on skin cancer rates. Int. J. Cancer 78:144–148, 1998.© 1998 Wiley‐Liss, Inc.

Changes in sun-related attitudes and behaviours, and reduced sunburn prevalence in a population at high risk of melanoma

This study aimed to determine trends in exposure to sunlight in the context of a melanoma prevention programme by monitoring the prevalence of sunburn and sun-related attitudes and behaviours. Telephone interviews were conducted in a baseline summer (December 1987 to February 1988) and two subsequent summers after the introduction of the SunSmart health promotion campaign. Interviewing a sample of 4,428 adult residents of the Australian city of Melbourne took place throughout summer on Monday evenings. Behavioural and sunburn data were reported for the previous weekend and relevant attitudinal data were collected. After adjusting for ambient ultraviolet radiation levels and temperature, survey month, age, sex and skin type, a significant reduction in sunburn was found. The crude proportion of sunburnt dropped from 11% to 10% to 7% over 3 years and the adjusted odds ratios (and 95% confidence intervals) were as follows: Year 1/Year 2; 0.75 (CI 0.57-0.99) and Year 1/Year 3; 0.59 (CI 0.43-0.81). Substantial attitudinal shifts occurred over the 3 years. Hat wearing increased significantly each year (19%, 26%, 29%), as did sunscreen use (12%, 18%, 21%). However, the trends in mean proportion of body surface area covered by clothing were less clear cut (0.67, 0.64, 0.71). It is concluded that melanoma risk factor exposure of populations can change fairly rapidly and that well-conducted health promotion campaigns can play a part in producing such change.

Melanoma prevention: behavioral and nonbehavioral factors in sunburn among an Australian urban population

BACKGROUND To determine the independent contribution of behavioral factors to the occurrence of sunburn, sun protection behavior was assessed over 13 successive summer weekends in a total of 1,655 adults in Melbourne, Australia. METHODS Telephone survey respondents provided detailed accounts of activities engaged in, time spent outside, and hat, clothing, and sunscreen coverage in the 4 hr around the solar midday on both weekend days, as well as skin type, sociodemographic descriptors, and degree of sunburn experienced. Independent measures of atmospheric temperature and ambient ultraviolet radiation (UVR) were added to individual records. RESULTS The (mostly recreational) weekend sunburn in this urban sample was strongly associated with UVR, as expected. Temperature at 3 PM, sensitive skin type, youthfulness, and being male were also independently associated with sunburn. After all other predictors were controlled for, the body exposure index (which took into account time outside and hat, clothing, and sunscreen coverage) made a strong independent contribution to the explanation of sunburn (P < 0.001). CONCLUSION It was concluded that behavior change strategies to prevent malignant melanoma of the skin are warranted.

The prevalence of common skin conditions in australian school students : 3. Acne vulgaris

The prevalence, severity and disability related to facial acne (comprising acne on the head and neck) was assessed in a randomized sample of 2491 students (aged 4–18 years) from schools throughout the State of Victoria in Australia. Students were diagnosed clinically by a dermatologist or dermatology registrar. The overall prevalence (including 4–7 year olds) was 36.1% (95% confidence intervals, CI 24.7–47.5), ranging from 27.7% (95% CI 20.6–34.8) in 10–12 year olds to 93.3% (95% CI 89.6–96.9) in 16–18 year olds. It was less prevalent among boys aged 10–12 years than girls of the same age; however, between the ages of 16 and 18 years, boys were more likely than girls to have acne. Moderate to severe acne was present in 17% of students (24% boys, 11% girls). Comedones, papules and pustules were the most common manifestations of acne, with one in four students aged 16–18 years having acne scars. Twelve per cent of students reported a high Acne Disability Index score. This tended to correlate with clinical severity, although there was some individual variation in perception of disability. Seventy per cent of those found to have acne on examination had indicated in the questionnaire that they had acne. Of those, 65% had sought treatment, a substantial proportion of which (varying with who gave the advice) was classified as being likely to have no beneficial effect. This is the first population‐based prevalence study on clinically confirmed acne published from Australia. The results show that acne is a common problem. They suggest the need for education programmes in schools to ensure that adolescents understand their disease, and know what treatments are available and from whom they should seek advice.

Descriptive epidemiology of acne vulgaris in the community

Acne is a common skin condition. No universally accepted standardized classification system for acne vulgaris exists, although there is a strong need for it Thus, the clinical definition of acne has been unclear in many studies. The reported prevalence of acne varies from 35 to over 90% of adolescents at some stage. In some studies the prevalence of comedones approaches 100% in both sexes during adolescence. The prevalence of acne varies between sexes and age groups, appearing earlier in females than in males, possibly reflecting the earlier onset of puberty. There is a greater severity of acne in males than in females in the late teens, which is compatible with androgens being a potent stimulus to sebum secretion. The prevalence of acne at a given age has been shown to be highly dependent on the degree of sexual maturity. Acne commonly shows a premenstrual increase in women. Some studies have detected seasonal variability in acne vulgaris, with the colder months associated with exacerbation and the warmer months showing improvement. Other studies have not confirmed these findings. Several studies that have investigated the psychosocial impact of acne have had conflicting results. The prevalence of severe acne has decreased over the past 20 years due to improved treatment. The general prevalence figure for acne may be confounded by treatment and this factor needs to be accounted for when collecting data.