Incidence and prevalence of non-melanoma skin cancer in Australia: A systematic review

Non-melanoma skin cancer (NMSC), including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), is the most common cancer occurring in people with fair skin. Australia has been reported to have the highest incidence of NMSC in the world. Using a systematic search of the literature in EMBASE and Medline, we identified 21 studies that investigated the incidence or prevalence of NMSC in Australia. Studies published between 1948 and 2011 were identified and included in the analysis. There were six studies that were conducted on national level, two at state level and 13 at the regional level. Overall, the incidence of NMSC had steadily increased over calendar-years in Australia. The incidence of NMSC per 100,000 person-years was estimated to be 555 in 1985; 977 in 1990; 1109 in 1995; 1170 in 2002 and 2448 in 2011. The incidence was higher for men than women and higher for BCC than SCC. Incidence varied across the states of Australia, with the highest in Queensland. The prevalence of NMSC was estimated to be 2% in Australia in 2002. The incidence and prevalence of NMSC still need to be accurately established at both national and state levels to determine the costs and burden of the disease on the public health system in Australia.

Prevalence of solar damage and actinic keratosis in a Merseyside population

This study examines the prevalence of sun-related damage to the skin in a caucasian population in north-west England. The importance of constitutional factors (complexion, skin type and age) as well as environmental and occupational exposures for the development of actinic keratosis (AK) and skin cancers was assessed in people over 40 years of age attending outpatient clinics (non-dermatology) at four centres in north-west England (Mersey region). Nine hundred and sixty-eight volunteers (531 men and 437 women) were recruited. The overall prevalence of AK was 15.4% in men and 5.9% in women. The prevalence was strongly related to age in both sexes, being 34.1% and 18.2%, respectively, in men and women aged 70 years and above, and was most strongly related to two objective signs of sun exposure, namely degree of solar elastosis and presence of solar lentigines. The prevalence of AK was higher in subjects with red hair and freckles, particularly women. There was no evidence of an increased prevalence of AK in relation to any occupation. There was a high prevalence of seborrhoeic keratosis and viral warts in both sexes, which was age-related in the case of seborrhoeic keratosis. Ten cases of basal cell carcinoma, eight cases of Bowen's disease and one case of malignant melanoma were identified. This study shows that the sun exposure received in 'normal' life in England is sufficient to cause potentially malignant skin damage in a significant proportion of the population.

The actinic keratosis. A perspective and update

BACKGROUND

Actinic keratosis (AK) is a common sun-induced precancerous neoplasm confined to the epidermis. It is the initial manifestation of a continuum of clinical and histologic abnormalities that progresses to invasive squamous cell carcinoma (SCC), a disorder that accounts for thousands of preventable deaths in America each year.

OBJECTIVE

The purpose of this work is to describe the actinic keratosis.

METHODS

This effort was performed by a literature review and analysis.

RESULTS

Like SCCs, the vast majority of AKs are asymptomatic. Although some actinic keratoses may become clinically inapparent, possibly either due to immune rejection or simply having their external surface unknowingly scraped off, an untreated AK represents a potentially curable fatal cancer.

CONCLUSIONS

Each AK should be treated before it progresses to invasive squamous cell carcinoma. Destructive modalities such as cryosurgery using liquid nitrogen and electrodesiccation and curettage are the mainstays of therapy. Each case must be individualized.

LEARNING OBJECTIVES

After studying this article, participant should be able to: 1. Understand the concept of an actinic keratosis. 2. Learn how to recognize its clinical manifestations. 3. Be aware of the danger it poses as an easily curable papulonodule that may become a fatal cancer.

Premalignant keratinocytic neoplasms

Premalignant keratinocytic keratoses are common, especially in pale-complected persons in whom they appear most often as an actinic keratosis. Although the actinic keratosis has a very low malignant potential, arsenic, tar, thermal, scar, reactional, and radiation keratoses may be more clinically aggressive. This article discusses these premalignant keratinocytic neoplasms.

Epidemiology of solar keratoses

Solar keratoses (SKs) or actinic keratoses are common dysplastic epidermal lesions which occur in pale-skinned individuals who are chronically exposed to intense sunlight. Together with basal cell carcinomas and squamous cell carcinomas, they constitute a major public health problem in such individuals. Reported SK prevalence rates range from 11 to 25% in various northern hemisphere populations, and amongst Australian adults the range is from 40 to 60%. In the only study to date reporting SK incidence data, 60% of subjects aged 40 years and over with SKs at baseline developed new lesions during 12 months of follow-up, compared with only 19% of those who were lesion-free on the first examination. Because existing epidemiological data on SKs are sparse, very little is known of their natural history, their role in carcinogenesis, or their preventability. In this review, current knowledge about the aetiology, diagnosis, and occurrence of SKs is discussed, as is the need for prospective studies in unselected communities. With accurate baseline data, public health authorities should be in a better position to determine the best preventive strategies, and to evaluate the effectiveness of these programmes.

Squamous cell carcinoma of the skin (excluding lip and oral mucosa)

The striking impression obtained from reviewing the cancer literature is how difficult it is to analyze the data for answers to many important biologic, behavioral, prognostic, and therapeutic questions about squamous cell carcinoma of the skin. This article addresses current concepts, controversies, and management of cutaneous squamous cell carcinoma (excluding the lip and oral mucosa).

The incidence of non-melanocytic skin cancers in an Australian population: results of a five-year prospective study

Two thousand, six hundred and sixty-nine persons who were aged 40 years and older attended for examination of the light-exposed areas of the head and neck, forearms and dorsa of the hands during a skin-cancer survey of the population of Maryborough, which was conducted annually for five years from 1982-1986 inclusive. Sixty (2.25%) persons--12 persons each with a squamous-cell carcinoma and 48 persons with a total of 51 basal-cell carcinomas--had at least one non-melanocytic skin cancer at the first examination. One thousand, nine hundred and eighty-one (74% of the study population) persons were seen on more than one occasion, which allowed for 6288 person-years of follow-up for the determination of the incidence of new cancers. The findings showed a calculated minimal age-standardized incidence rate of 873 non-melanocytic skin cancers/100,000 population each year. The minimal incidence rate for basal-cell carcinomas was 672 cases/100,000 population each year and for squamous-cell carcinomas was 201 cases/100,000 population each year. The rate ratio of the incidence of basal-cell carcinomas to that of squamous-cell carcinomas was 3.34 to one. Age, sex, skin reaction to sunlight and occupation all were significant factors in the determination of the risk of developing non-melanocytic skin cancers. The enormous costs that are involved in the treatment of non-melanocytic skin cancers and related lesions suggest that more time, effort and money need to be spent to reduce what has become a major public-health problem in Australia.

Relationship of solar keratosis and history of skin cancer to objective measures of actinic skin damage

Two methods for the assessment of severity of actinic skin damage were evaluated in a population-based survey of 1216 subjects. After controlling for the effects of age, skin texture changes graded by cutaneous microtopography were found to be associated strongly with the presence of solar keratoses and a past history of non-melanotic skin cancer. Changes in skin condition graded by paraocular photography had a weaker relationship with the presence of keratoses and showed no association with non-melanotic skin cancer. These results, together with a higher level of agreement between observers in grading cutaneous microtopographs, support the use of cutaneous microtopography as an index of actinic skin damage in epidemiological research.

Non-melanotic skin cancer and solar keratoses in Victoria

The light-exposed areas of the head and neck, forearms, and dorsum of each hand were examined in 2113 adults during a one-week study. The study was conducted in the isolated Victorian rural city of Maryborough which is situated in the northern part of the Central Highlands district. Of 2113 subjects, 49 (2.32%) had at least one skin cancer and 1202 (56.9%) had at least one solar keratosis. Histological confirmation of all skin cancers and doubtful solar keratoses was obtained. Age, skin type, and sunlight exposure were the major factors influencing the prevalence of solar keratoses and skin cancers.

Basal cell carcinoma in Queensland

An analysis is presented of a referred series of 1411 basal cell carcinomas treated by surgical excision and plastic surgical repair in which 259 were recurrent after previous other treatments. Of the 1,411 BCCs treated there were 10 BCCs which recurred (0.7% recurrence rate). A further 10 BCCs were primarily re-excised because of inadequate clearance around the tumour found on histological examination. (0.7% primary re-excision). The cases recurrent after previous treatment did not behave badly in terms of subsequent recurrence as they were widely excised and carefully observed in the postoperative years. Surgery must aim to be curative. We clearly define the tumour margin using magnification and mark an adequate clearance of surrounding normal tissue. This is then excised in width and depth. Repair of the defect is carried out to restore the area to as near normal as possible. Surgical repair is able to bring new tissue into the area to further enable it to withstand the rigours of the climate and not leave behind a premalignant scarred area.