Prostate cancer incidence in Australia correlates inversely with solar radiation.

UNLABELLED: What's known on the subject? and What does the study add? Increased sun exposure and blood levels of vitamin D have been postulated to be protective against prostate cancer. This is controversial. We investigated the relationship between prostate cancer incidence and solar radiation in non-urban Australia, and found a lower incidence in regions receiving more sunlight. In landmark ecological studies, prostate cancer mortality rates have been shown to be inversely related to ultraviolet radiation exposure. Investigators have hypothesised that ultraviolet radiation acts by increasing production of vitamin D, which inhibits prostate cancer cells in vitro. However, analyses of serum levels of vitamin D in men with prostate cancer have failed to support this hypothesis. This study has found an inverse correlation between solar radiation and prostate cancer incidence in Australia. Our population (previously unstudied) represents the third group to exhibit this correlation. Significantly, the demographics and climate of Australia differ markedly from those of previous studies conducted on men in the United Kingdom and the United States. OBJECTIVE: • To ascertain if prostate cancer incidence rates correlate with solar radiation among non-urban populations of men in Australia. PATIENTS AND METHODS: • Local government areas from each state and territory were selected using explicit criteria. Urban areas were excluded from analysis. • For each local government area, prostate cancer incidence rates and averaged long-term solar radiation were obtained. • The strength of the association between prostate cancer incidence and solar radiation was determined. RESULTS: • Among 70 local government areas of Australia, age-standardized prostate cancer incidence rates for the period 1998-2007 correlated inversely with daily solar radiation averaged over the last two decades. CONCLUSION: • There exists an association between less solar radiation and higher prostate cancer incidence in Australia.

Pharmaceutical advertisement claims in Australian medical publications.

OBJECTIVE: To determine the quality of claims in advertisements published in Australian medical publications, describe how benefits and harms are presented, and examine the level of underpinning evidence. DESIGN AND SETTING: Audit of a consecutive three-month sample of advertisements appearing in six popular Australian medical publications. MAIN OUTCOME MEASURES: Proportion of advertisements with quantitative information; proportion of claims conveying clinical outcomes; where retrievable, level of underpinning evidence. RESULTS: Of 1504 claims, 855 could be substantiated quantitatively. Of these, 45% were supported by compelling evidence (randomised controlled trials or better). Of 13 claims explicitly reporting quantitative outcomes, none provided the absolute risk reduction or the number needed to treat. CONCLUSIONS: Our audit invites greater diligence by pharmaceutical companies in substantiating their claims and greater vigilance among clinicians when reading them.