title: Association Between Parkinson Disease and Risk of Cancer in Taiwan.
abstract: OBJECTIVE
  Parkinson disease (PD) has been reported to be associated with a general reduced risk of cancer. These studies were mainly carried out in Western populations and little was known about associations in East Asians.
  
  
  OBJECTIVE
  To analyze the association between PD and risk of cancer.
  
  
  METHODS
  In this cohort study, the data were obtained from the Taiwan National Health Insurance Research Database, which contained information on approximately 24.7 million insured individuals. The cohort included individuals with newly diagnosed as having PD between 2004 and 2010. An age- and sex-matched systematic random-sampling method was used for subject selection in the reference non-PD cohort. Multivariate Cox proportional hazard regression analysis was used to determine the effects of PD on the risks of cancer, as shown by hazard ratios (HRs) with 95% CIs.
  
  
  METHODS
  The Taiwan Population Census and National Cancer Registry Databases were used to identify patients with cancer. The last follow-up date was December 31, 2012.
  
  
  RESULTS
  In 62 023 patients with PD, the HR for all subsequent cancers combined was 1.58 (95% CI, 1.50-1.65). Of the 19 types of cancer, Parkinson disease was not associated with breast, ovarian, or thyroid cancers. Increased HRs were found in the remaining 16 cancers, including malignant brain tumors (HR, 3.42; 95% CI, 1.84-6.38), gastrointestinal tract cancers (esophageal [HR, 1.81; 95% CI, 1.28-2.57], stomach [HR, 1.59; 95% CI, 1.30-1.94], colorectal [HR, 1.47; 95% CI, 1.31-1.65], liver [HR, 1.89; 95% CI, 1.67-2.14]; gallbladder [HR, 1.73; 95% CI, 1.16-2.57], and pancreas [HR, 1.48; 95% CI, 1.09-2.02]) (P < .05 for all comparisons), lung cancers (HR, 1.56; 95% CI, 1.38-1.76), some hormone-related cancers (uterine [HR, 1.83; 95% CI, 1.12-3.01], cervical [HR, 1.36; 95% CI, 1.05-1.76], and prostate [HR, 1.80; 95% CI, 1.52-2.13; P < .05 for all comparisons), urinary tract cancers (kidney and bladder cancers; HRs, 1.59 and 1.99, respectively; P < .001 for both comparisons), lymphoma and/or leukemia (HR, 1.62; 95% CI, 1.31-2.01), melanoma (HR, 2.75; 95% CI, 1.35-5.59), and other skin cancers (HR, 1.81; 95% CI, 1.46-2.23). For hepatocellular carcinoma, the highest HR resided in the 50- to 59-year-old group (HR, 2.57; 95% CI, 1.7-3.89).
  
  
  CONCLUSIONS
  Our study concludes that PD is is associated with most cancers in Taiwan. Further studies are needed to clarify whether our findings can be applied to other East Asian populations. The differences between our study and most previous cohorts suggest the importance of ethnicity and environmental exposures in disease pathogenesis.
authors.affiliation: Taiwan International Graduate Program in Molecular Medicine, Academia Sinica and National Yang-Ming University, Taipei, Taiwan2Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan3Institute of Biochemistry and Molecular Biology, National Yang.
authors.forename: Pei-Ying
authors.initials: PY
authors.lastname: Lin
authors.affiliation: Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan6PhD Program for Cancer Biology and Drug Discovery, China Medical University, Taichung, Taiwan.
authors.forename: Shih-Ni
authors.initials: SN
authors.lastname: Chang
authors.affiliation: Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Tzu-Hung
authors.initials: TH
authors.lastname: Hsiao
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan4Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan.
authors.forename: Bo-Tsang
authors.initials: BT
authors.lastname: Huang
authors.affiliation: Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Ching-Heng
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan4Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan.
authors.forename: Pan-Chyr
authors.initials: PC
authors.lastname: Yang
mesh_terms: D000368:Aged; D044466:Asian People; D016022:Case-Control Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009369:Neoplasms / Q000175:diagnosis / Q000208:ethnology*; D010300:Parkinson Disease / Q000175:diagnosis / Q000208:ethnology*; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors