Sun exposure and melanoma survival: a GEM study.
Level 3 - non-randomized controlled study
Multicenter prospective/longitudinal cohort study of melanoma patients
PubMed 25069694 · doi:10.1158/1055-9965.EPI-14-0431
What was done
Researchers conducted an international, multicenter, population-based study across Australia, Italy, Canada, and the United States including 3,578 melanoma cases followed for an average of 7.4 years. The study evaluated whether pre-diagnosis sun exposure was associated with melanoma-specific survival. Sun exposure metrics included history of sunburn, intermittent exposure (hours of holiday sun exposure and water-related outdoor activities), estimated ambient ultraviolet B dose, histologic solar elastosis, and season of diagnosis.
What was found
The abstract reports no numeric hazard ratios, survival rates, or confidence intervals. Having had any sunburn in one year within 10 years of diagnosis was reported as inversely associated with survival (an apparent protective effect), whereas solar elastosis, estimated ambient UVB dose, and intermittent exposure measures showed no association with melanoma-specific survival. Overall evidence for an association was reported as weak.
Why it matters
This study challenges earlier findings that suggested pre-diagnosis UV exposure improved melanoma prognosis, demonstrating in a larger international cohort that pre-diagnostic sun exposure has little effect on melanoma survival.
Limits
No specific numerical risk estimates or confidence intervals are provided in the abstract. Exposure measures largely depended on retrospective self-reports susceptible to recall bias, and ambient UVB estimates represent geographic proxies rather than direct individual exposure measurements.
Cited by
- contradicts Chronic regular daily sun exposure is inversely associated with melanoma mortality across all published studies.