title: Hair dye use, regular exercise, and the risk and prognosis of prostate cancer: multicenter case-control and case-only studies.
abstract: BACKGROUND
  This study investigated the effects that hair dye use and regular exercise exert on the risk and prognosis of prostate cancer.
  
  
  METHODS
  We studied 296 cases of histologically confirmed prostate cancer and 296 age- (in 2-y bands), ethnicity-, and hospital-matched controls in Taiwan between August 2000 and December 2008. To determine the rate of prostate cancer survival, another 608 incident prostate cancer cases occurring between August 2000 and December 2007 were investigated. Information on hair dye use and regular exercise was obtained using a standardized questionnaire.
  
  
  RESULTS
  The use of hair dyes was associated with a significant 2.15-fold odds of developing prostate cancer (adjusted odds ratio = 2.15, 95% confidence interval [CI] = 1.32-3.57), but was not associated with prostate cancer survival, compared with no use. The significant risks were more prominent in users aged < 60 years who had used hair dyes for > 10 years, > 6 times per year, and started using hair dyes before 1980. By contrast, regular exercise significantly reduced the number of prostate-cancer-specific death (adjusted hazard ratio = 0.37, 95% CI = 0.16-0.83); the protective effect of exercise was more prominent among cancer patients who exercised daily (≥ 7 times/week). However, exercise could not prevent the development of prostate cancer.
  
  
  CONCLUSIONS
  Hair dye use increased the risk of prostate cancer, whereas regular exercise reduced the number of prostate-cancer-specific deaths.
authors.affiliation: Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, R.O.C, Taiwan.|Department of Family Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, R.O.C, Taiwan.|Department of Family Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, R.O.C, Taiwan.|Department of Family Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, R.O.C, Taiwan.
authors.forename: Shu-Yu
authors.initials: SY
authors.lastname: Tai
authors.affiliation: Department of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, R.O.C, Taiwan.
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: Hsieh
authors.affiliation: Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, R.O.C, Taiwan. shpihu@yahoo.com.tw.|Department of Urology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, R.O.C, Taiwan. shpihu@yahoo.com.tw.
authors.forename: Shu-Pin
authors.initials: SP
authors.lastname: Huang
authors.affiliation: Department of Family Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, R.O.C, Taiwan. 960021@ms.kmuh.org.tw.|Department of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, R.O.C, Taiwan. 960021@ms.kmuh.org.tw.|Center of Environmental and Occupational Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, R.O.C, Taiwan. 960021@ms.kmuh.org.tw.
authors.forename: Ming-Tsang
authors.initials: MT
authors.lastname: Wu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005081:Exercise Therapy; D006202:Hair Dyes / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000139:chemically induced / Q000503:physiopathology / Q000628:therapy*; D012307:Risk Factors; D013624:Taiwan
chemical_list: D006202:Hair Dyes
keywords: Case–control study; Hair dye; Prostate cancer; Regular exercise; Risk; Survival