Introduction
Surfing and swimming are two popular recreational aquatic activities in Australia, with an estimated 2.7 million surfers1 and three million swimmers nationwide.2 These activities are associated with intermittent exposure to ultraviolet radiation (UVR), which is recognized as a causal mechanism in the development of non-melanoma (NMSC) and melanoma skin cancer (MSC).3 Intermittent exposure to UVR has been well documented to lead to development of actinic keratosis (AK) lesions, non-melanoma basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and melanoma skin cancer (MSC).4 Australia is recognized as having the highest incidence (per 100,000) of NMSC and MSC in the world.5
Ultraviolet radiation in southeast Queensland is the second highest with a UVR range 4-12 and a mean of 7.9. A UVR index of three or greater is recognized as requiring sun protection strategies for the prevention of skin cancer.6
Skin Cancer Australia reported approximately one-third of Australians (30.8%) had skin cancer, making it the most common type of cancer in Australia.7 Of skin cancers, NMSC, particularly BCC was reported to have the highest age-standardized rate (1,541 per 100,000) followed by SCC (1,035 per 100,000) and MSC (53.5 cases per 100,000).8,9Melanoma skin cancers were the costliest in Queensland with the highest proportion of total paid Medicare services related to MSC (~ 30%) compared to the proportion of Australian’s living in Queensland.10
The prevalence of skin cancer in swimmers is poorly reported in the literature, with only a single study conducted in the Netherlands11 and none to date conducted in Australia. The paucity of research in swimmers is also mirrored when investigating skin cancer in Australian surfers. Climstein et al., 12conducted an online survey of 1,348 Australian surfers and reported BCCs as the most prevalent (6.8%, 9,124 per 100,000) followed by MSC (1.4%, 1,854 per 100,000) and SCCs (0.6%, 2,670 per 100,000). The MSC rate was more than 34-fold that of the Australian general population (53.5 per 100,000).9 It should be noted that this study used a retrospective design and relied on the participant’s ability to self-report diagnosed skin cancers. Given the limited evidence and the lack of objective testing methods we therefore, sought to determine the point prevalence of NMSC and MSC in surfers and outdoor swimmers in southeast Queensland and Northern New South Wales through whole-body skin cancer examination. Confirmation of skin cancer was attained via histopathology.