title: Sun exposure and the risk of prostate cancer in the Singapore Prostate Cancer Study: a case-control study.
abstract: BACKGROUND
  Most of the epidemiology studies on the effects of sun exposure and prostate cancer were conducted among the temperate countries of North America and Europe. Little is known about the influence on Asian populations. The purpose of current study was to evaluate any association of sun exposure with risk of prostate cancer in Chinese, Malays and Indians who reside in the tropics.
  
  
  METHODS
  The Singapore Prostate Cancer Study is a hospital-based case-control study of 240 prostate cancer incident cases and 268 controls conducted in Singapore between April 2007 and May 2009. Detailed information on outdoor activities in the sun, skin colour, sun sensitivity and other possible risk factors were collected in personal interviews. Cases were further classified by Gleason scores and TNM staging. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis, adjusted for age, ethnicity, education, family history of any cancers, BMI and skin colour.
  
  
  RESULTS
  We found that prostate cancer risk was increased in subjects with black/dark-brown eyes (OR 5.88, 95%CI 3.17-10.9), darker skin colour e.g. tan/dark brown/black (OR 7.62, 95%CI 3.41-17.0), frequent sunburn in lifetime (OR 4.30, 95%CI 1.7-11.2) and increased general sun exposure in adulthood per week (OR 2.03, 95%CI 1.09-3.81). The increased risk was consistent for high grade tumours and advanced stage prostate cancers.
  
  
  CONCLUSIONS
  The findings from this study suggest that excessive sun exposure is a risk factor for prostate cancer in Asians.
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore. sin_eng_chia@nuhs.edu.sg
authors.forename: Sin-Eng
authors.initials: SE
authors.lastname: Chia
authors.forename: Kin-Yoke
authors.initials: KY
authors.lastname: Wong
authors.forename: Christopher
authors.initials: C
authors.lastname: Cheng
authors.forename: Weber
authors.initials: W
authors.lastname: Lau
authors.forename: Puay-Hoon
authors.initials: PH
authors.lastname: Tan
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D002681:China / Q000208:ethnology; D004781:Environmental Exposure / Q000009:adverse effects / Q000706:statistics & numerical data*; D005127:Eye Color; D006801:Humans; D007194:India / Q000208:ethnology; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000208:ethnology / Q000209:etiology; D012306:Risk; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology; D012880:Skin Pigmentation; D013472:Sunlight / Q000009:adverse effects*