Sun exposure and mortality from melanoma.
Level 3 - non-randomized controlled study
Longitudinal cohort study of melanoma cases followed for survival outcomes
PubMed 15687362 · doi:10.1093/jnci/dji019
What was done
A population-based cohort of 528 patients with cutaneous melanoma was followed for an average of over 5 years. In-person interviews assessed measures of intermittent sun exposure, perceived skin awareness, skin self-screening, and physician screening. Histopathology was reviewed for parameters including solar elastosis, Breslow thickness, mitoses, and ulceration. Competing risk models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for melanoma mortality.
What was found
Sunburn, high intermittent sun exposure, skin awareness histories, and solar elastosis were statistically significantly inversely associated with melanoma death. In a multivariable competing risk analysis adjusting for Breslow thickness, mitotic index, and head and neck location: - Skin awareness was associated with reduced mortality (with vs. without: HR = 0.5, 95% CI = 0.3 to 0.9, P = .022). - Solar elastosis was associated with reduced mortality (present vs. absent: HR = 0.4, 95% CI = 0.2 to 0.8, P = .009). Melanoma thickness, mitoses, ulceration, and head and neck location were significantly positively associated with melanoma death.
Why it matters
This study shows that solar elastosis, a histologic marker of sun damage, along with skin awareness, is independently associated with better melanoma survival after accounting for tumor thickness and other standard prognostic factors.
Limits
Measures of sun exposure and screening behaviors relied on retrospective self-reports from in-person interviews, introducing potential recall bias. The sample size was limited to 528 cases, and the observational cohort design cannot establish causality or entirely exclude unmeasured confounding.
Cited by
- contradicts Sunburning increases the risk of melanoma mortality.