title: Sun exposure and risk of lymphoid neoplasms in Singapore.
abstract: BACKGROUND
  Epidemiologic studies have reported an inverse association between sun exposure and non-Hodgkin lymphoma (NHL), but these have been almost exclusively conducted in Western populations residing in temperate locations. We evaluated the association between personal outdoor sun exposure and risk of malignant lymphomas in Singapore.
  
  
  METHODS
  A hospital-based case-control study of 541 incident cases of lymphoid neoplasms and 830 controls were recruited during 2004-2008. Participants were interviewed regarding recreational or occupational outdoor activities during childhood and in adulthood. Basic demographics and potential confounders were also collected. Odds ratios (OR) and 95 % confidence intervals (CI) were calculated using unconditional logistic regression analysis.
  
  
  RESULTS
  Compared with individuals who did not have regular sun exposure, a lower risk of NHL was observed for those who reported regular exposure on non-school days during childhood [OR, 0.62; 95 % CI, 0.46-0.83] and non-working days in adulthood [OR, 0.70; 95 % CI, 0.51-0.97]. The protective effect was more evident among women.
  
  
  CONCLUSIONS
  Our findings support an inverse relationship between intermittent sun exposure and the risk of NHL. These findings are consistent with the growing evidence from various countries, but further studies, especially prospective studies, are needed in Asian populations.
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
authors.forename: Kin-Yoke
authors.initials: KY
authors.lastname: Wong
authors.forename: Bee-Choo
authors.initials: BC
authors.lastname: Tai
authors.forename: Sin-Eng
authors.initials: SE
authors.lastname: Chia
authors.forename: Ponnudurai
authors.initials: P
authors.lastname: Kuperan
authors.forename: Khai-Mun
authors.initials: KM
authors.lastname: Lee
authors.forename: Soon-Thye
authors.initials: ST
authors.lastname: Lim
authors.forename: Susan
authors.initials: S
authors.lastname: Loong
authors.forename: Benjamin
authors.initials: B
authors.lastname: Mow
authors.forename: Siok-Bian
authors.initials: SB
authors.lastname: Ng
authors.forename: Leonard
authors.initials: L
authors.lastname: Tan
authors.forename: Soo-Yong
authors.initials: SY
authors.lastname: Tan
authors.forename: Suat-Hoon
authors.initials: SH
authors.lastname: Tan
authors.forename: Miriam
authors.initials: M
authors.lastname: Tao
authors.forename: Alvin
authors.initials: A
authors.lastname: Wong
authors.forename: Gee-Chuan
authors.initials: GC
authors.lastname: Wong
authors.forename: Adeline
authors.initials: A
authors.lastname: Seow
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D016015:Logistic Models; D008223:Lymphoma / Q000145:classification / Q000453:epidemiology*; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology; D013472:Sunlight; D013997:Time Factors; D055815:Young Adult