Indoor tanning and risk of melanoma: a case-control study in a highly exposed population.
BACKGROUND
Indoor tanning has been only weakly associated with melanoma risk; most reports were unable to adjust for sun exposure, confirm a dose-response, or examine specific tanning devices. A population-based case-control study was conducted to address these limitations.


METHODS
Cases of invasive cutaneous melanoma, diagnosed in Minnesota between 2004 and 2007 at ages 25 to 59, were ascertained from a statewide cancer registry; age-matched and gender-matched controls were randomly selected from state driver's license lists. Self-administered questionnaires and telephone interviews included information on ever use of indoor tanning, types of device used, initiation age, period of use, dose, duration, and indoor tanning-related burns. Odds ratios (OR) and 95% confidence intervals (CI) were adjusted for known melanoma risk factors.


RESULTS
Among 1,167 cases and 1,101 controls, 62.9% of cases and 51.1% of controls had tanned indoors (adjusted OR 1.74; 95% CI, 1.42-2.14). Melanoma risk was pronounced among users of UVB-enhanced (adjusted OR, 2.86; 95% CI, 2.03-4.03) and primarily UVA-emitting devices (adjusted OR, 4.44; 95% CI, 2.45-8.02). Risk increased with use: years (P < 0.006), hours (P < 0.0001), or sessions (P = 0.0002). ORs were elevated within each initiation age category; among indoor tanners, years used was more relevant for melanoma development.


CONCLUSIONS
In a highly exposed population, frequent indoor tanning increased melanoma risk, regardless of age when indoor tanning began. Elevated risks were observed across devices.


CONCLUSIONS
This study overcomes some of the limitations of earlier reports and provides strong support for the recent declaration by the IARC that tanning devices are carcinogenic in humans.
Lazovich
DeAnn
D
Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN 55454, USA. lazov001@umn.edu
Vogel
Rachel Isaksson
RI
Berwick
Marianne
M
Weinstock
Martin A
MA
Anderson
Kristin E
KE
Warshaw
Erin M
EM
D000328:Adult; D001505:Beauty Culture; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000453:epidemiology / Q000209:etiology*; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D012307:Risk Factors; D012867:Skin / Q000528:radiation effects*; D012878:Skin Neoplasms / Q000453:epidemiology / Q000209:etiology*; D011795:Surveys and Questionnaires; D014466:Ultraviolet Rays / Q000009:adverse effects