Accessibility to air travel correlates strongly with increasing melanoma incidence*

Abstract

As the cost of air travel has decreased substantially in the USA and Europe over the past few decades, leisure travel to vacation destinations during the winter months has expanded significantly. This trend has probably increased the incidence of significant ultraviolet radiation exposure and sunburn in a broader population who could not previously afford this kind of travel. The purpose of this study was to analyse the correlation between increasing accessibility to air travel and melanoma incidence. This ecological study surveyed air travel patterns and melanoma incidence over the past three decades. Melanoma age-adjusted incidence was obtained from the United States Surveillance, Epidemiology, and End Results 9 Registry Database, 1975-2000, and the Cancer Registry of Norway, 1965-2000. United States mean inflation-adjusted airfare prices for four airports linked to leisure destinations (Miami, Los Angeles, San Diego, Phoenix) were compared with melanoma incidence. Parallel analyses were performed using annual domestic passenger-kilometres and melanoma incidence in Norway. Declining United States leisure-specific airfares corresponded strongly with increasing melanoma incidence (r = 0.96, r = 0.92, P < 0.001). Modelling a 5-year time lag between airfare and melanoma diagnosis strengthened the association (r = 0.98, r = 0.96, P < 0.001). Longer time lags could not be modelled due to data limitations. Data from Norway similarly showed that increasing air passenger mileage corresponded strongly with increasing melanoma incidence. Although correlation does not equate to causality, the very strong relationship between increasing access to air travel and melanoma incidence suggests that changes in recreational patterns may be contributing significantly to the public health problem of melanoma.

Incidence and survival in patients with cutaneous melanoma by morphology, anatomical site and TNM stage: A Danish Population-based Register Study 1989–2011

“…They proposed that the high incidence of sunburn may explain why Scandinavia has the highest incidence of skin cancer in Europe [39]. Other studies have also directly linked vacations abroad to the increasing incidence of melanoma in populations of mainly European origin [41,42]. The increased recreational sun exposure may be a consequence of declining airfares and improved accessibility to foreign travel [41,42].…”

“…Other studies have also directly linked vacations abroad to the increasing incidence of melanoma in populations of mainly European origin [41,42]. The increased recreational sun exposure may be a consequence of declining airfares and improved accessibility to foreign travel [41,42]. Another likely contributing factor in increased melanoma incidence is a change from predominantly occupational to predominantly recreational patterns of sun exposure [43].…”

Critique of the International Agency for Research on Cancer meta-analyses of the association of sunbed use with risk of cutaneous malignant melanoma

“…Those at higher latitudes frequently travel to the Mediterranean area, which has also been associated with increased risk of CMM. 33,34 Thus, risk of melanoma increases with latitude in European countries. 24,32 That the RR for sunbed use and incidence of CMM increases with increasing latitude is probably also attributable to lower solar UV irradiance for those who do not use sunbeds.…”

“…If the interest in regulating use of indoor tanning facilities is to try to stem the rising trends of melanoma worldwide, it is important to examine all factors that may be causing the trends. Some identified as such include increased travel to sunny locations, 33,34 use of sunscreen that blocks UVB but does not block UVA well, 44 and increased UVA irradiance due to increased window area in home and office buildings. 73 For example, US nonmelanoma skin cancer mortality rates decreased between 1950-1954 and 1970-1974, whereas CMM rates increased during that time and have continued rising.…”

“…A growing body of literature indicates that vitamin D reduces the risk of CMM. Recent work outlined the case for a beneficial role of vitamin D. 34 Dietary vitamin D correlated inversely with incidence of CMM. 37 Some recent evidence indicates a reduced risk of CMM with respect to vitamin D. 57 Levels of 25(OH)D in the blood serum have decreased in the US 58,59 and the UK, 60 and levels in Australia are lower than expected for such a sunny country.…”