title: Ambient UV, personal sun exposure and risk of multiple primary melanomas.
abstract: OBJECTIVE
  Sun exposure is the main cause of melanoma in populations of European origin. No previous study has examined the effect of sun exposure on risk of multiple primary melanomas compared with people who have one melanoma.
  
  
  METHODS
  We identified and enrolled 2,023 people with a first primary melanoma (controls) and 1,125 with multiple primary melanomas (cases) in seven centers in four countries, recorded their residential history to assign ambient UV and interviewed them about their sun exposure.
  
  
  RESULTS
  Risk of multiple primary melanomas increased significantly (P<0.05) to OR=2.10 for the highest exposure quarter of ambient UV irradiance at birth and 10 years of age, to OR=1.38 for lifetime recreational sun exposure, to OR=1.85 for beach and waterside activities, to OR=1.57 for vacations in a sunnier climate, to OR=1.50 for sunburns. Occupational sun exposure did not increase risk (OR=1.03 for highest exposure). Recreational exposure at any age increased risk and appeared to add to risk from ambient UV in early life.
  
  
  CONCLUSIONS
  People who have had a melanoma can expect to reduce their risk of a further melanoma by reducing recreational sun exposure whatever their age. The same is probably true for a person who has never had a melanoma.
authors.affiliation: School of Public Health, University of Sydney, Edward Ford Building A27, NSW, 2006, Australia, and Women's College Hospital, Toronto, ON, Canada. annek@health.usyd.edu.au
authors.forename: Anne
authors.initials: A
authors.lastname: Kricker
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Armstrong
authors.forename: Chris
authors.initials: C
authors.lastname: Goumas
authors.forename: Melisa
authors.initials: M
authors.lastname: Litchfield
authors.forename: Colin B
authors.initials: CB
authors.lastname: Begg
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Hummer
authors.forename: Loraine D
authors.initials: LD
authors.lastname: Marrett
authors.forename: Beth
authors.initials: B
authors.lastname: Theis
authors.forename: Robert C
authors.initials: RC
authors.lastname: Millikan
authors.forename: Nancy
authors.initials: N
authors.lastname: Thomas
authors.forename: Hoda Anton
authors.initials: HA
authors.lastname: Culver
authors.forename: Richard P
authors.initials: RP
authors.lastname: Gallagher
authors.forename: Terence
authors.initials: T
authors.lastname: Dwyer
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Rebbeck
authors.forename: Peter A
authors.initials: PA
authors.lastname: Kanetsky
authors.forename: Klaus
authors.initials: K
authors.lastname: Busam
authors.forename: Lynn
authors.initials: L
authors.lastname: From
authors.forename: Urvi
authors.initials: U
authors.lastname: Mujumdar
authors.forename: Roberto
authors.initials: R
authors.lastname: Zanetti
authors.forename: Marianne
authors.initials: M
authors.lastname: Berwick
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000209:etiology*; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000209:etiology*; D009381:Neoplasms, Radiation-Induced; D016273:Occupational Exposure; D016017:Odds Ratio; D011829:Radiation Dosage; D012307:Risk Factors; D040242:Risk Reduction Behavior; D012878:Skin Neoplasms / Q000209:etiology*; D013472:Sunlight / Q000009:adverse effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*