title: Familial aggregation of melanoma risks in a large population-based sample of melanoma cases.
abstract: OBJECTIVE
  Melanoma has been shown in numerous studies to be associated with sun exposure, and with host phenotypic factors of genetic origin. In this study we use information from a large series of incident cases of melanoma from an international population-based study to examine the patterns of incidence of melanoma in the first-degree relatives of these cases.
  
  
  METHODS
  A total of 2508 incident cases of melanoma provided information on basic demographic data and pigmentary characteristics, in addition to detailed information on family history of melanoma. These data were used to examine the incidence rates ratios of melanoma in the relatives of cases in relation to population rates, and also with respect to phenotypic characteristics of the probands that have been shown to be associated with melanoma: mole counts, hair color, eye color, and skin sensitivity to the sun.
  
  
  RESULTS
  The incidence rates reflect the underlying patterns of incidence in the source populations, with generally higher rates in the Australian sample, low rates in Italy, and intermediate rates in the USA and Canada. Also, rates are higher in men than in women, except at very young ages. Phenotypic characteristics of the probands were only weakly associated with the observed rates in the relatives although there is a strong inverse association with age at diagnosis. Cumulative risk of melanoma rises to 6.9% (6.1%) at age 80 in male (female) first-degree relatives of cases, and to 10.8% (9.5%) in relatives of cases diagnosed before age 50.
  
  
  CONCLUSIONS
  Relatives of cases diagnosed with melanoma are at considerable lifetime risk of the disease, especially if the case is diagnosed at a young age.
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. korvae@mskcc.org
authors.forename: Colin B
authors.initials: CB
authors.lastname: Begg
authors.forename: Amanda
authors.initials: A
authors.lastname: Hummer
authors.forename: Urvi
authors.initials: U
authors.lastname: Mujumdar
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Armstrong
authors.forename: Anne
authors.initials: A
authors.lastname: Kricker
authors.forename: Loraine D
authors.initials: LD
authors.lastname: Marrett
authors.forename: Robert C
authors.initials: RC
authors.lastname: Millikan
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Gruber
authors.forename: Hoda
authors.initials: H
authors.lastname: Anton-Culver
authors.forename: Judith B
authors.initials: JB
authors.lastname: Klotz
authors.forename: Roberto
authors.initials: R
authors.lastname: Zanetti
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: Marrianne
authors.initials: M
authors.lastname: Berwick
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001315:Australia / Q000453:epidemiology; D015331:Cohort Studies; D005192:Family Health; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D015994:Incidence; D008297:Male; D008545:Melanoma / Q000453:epidemiology* / Q000235:genetics; D008875:Middle Aged; D009656:North America / Q000453:epidemiology; D010641:Phenotype; D017678:Sex Distribution