title: Pigmentary characteristics, UV radiation exposure, and risk of non-Hodgkin lymphoma: a prospective study among Scandinavian women.
abstract: BACKGROUND
  UV radiation and pigmentary characteristics may be associated with non-Hodgkin lymphoma (NHL) risk, but few prospective studies exist. We investigated these associations in a Norwegian-Swedish cohort.
  
  
  METHODS
  The cohort included women ages 30 to 50 years at enrolment in 1991 to 1992. Host factors, and exposure to sun and artificial tanning devices in life-decades 0 to 50 years were collected by questionnaire. Relative risks (RR) with 95% confidence intervals (CI) were estimated by Poisson regression.
  
  
  RESULTS
  Among 104,953 women with complete follow-up through 2006 (Sweden) and 2007 (Norway), 158 were diagnosed with NHL. Women with brown hair had an increased risk of NHL compared with dark brown-haired/black-haired women (RR, 1.72; 95% CI, 1.08-2.74); decreased risks were found among women with gray, green or mixed (RR, 0.50; 95% CI, 0.32-0.77), or blue (RR, 0.54; 95% CI, 0.35-0.81) eyes compared with those with brown eyes, and among those with high propensity to burn compared with those with low propensity (RR, 0.57; 95% CI, 0.36-0.91). Annual number of sunburns and bathing vacations in any age decade, or ever use of artificial tanning devices were not significantly associated with NHL risk. After exposure at ages 10 to 39 years, RRs for ever versus never exposed were 0.99 (95% CI, 0.65-1.50) for sunburn, 1.00 (95% CI, 0.64-1.54) for bathing vacations, and 0.99 (95% CI, 0.67-1.46) for artificial tanning device use.
  
  
  CONCLUSIONS
  Whereas several pigmentary characteristics were associated with NHL risk, our results do not support an association between UV radiation and NHL.
  
  
  CONCLUSIONS
  Studies of UV radiation and NHL are warranted for etiologic understanding and public health recommendations.
authors.affiliation: Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway. m.b.veierod@medisin.uio.no
authors.forename: Marit Bragelien
authors.initials: MB
authors.lastname: Veierød
authors.forename: Karin Ekström
authors.initials: KE
authors.lastname: Smedby
authors.forename: Eiliv
authors.initials: E
authors.lastname: Lund
authors.forename: Hans-Olov
authors.initials: HO
authors.lastname: Adami
authors.forename: Elisabete
authors.initials: E
authors.lastname: Weiderpass
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology / Q000209:etiology*; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012537:Scandinavian and Nordic Countries / Q000453:epidemiology; D012880:Skin Pigmentation / Q000502:physiology*; D014466:Ultraviolet Rays / Q000009:adverse effects*