title: A nationwide population-based retrospective cohort study of the risk of uterine, ovarian and breast cancer in women with polycystic ovary syndrome.
abstract: BACKGROUND
  Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders among women of reproductive age. We used a nationwide population-based retrospective cohort study to explore the relationship between PCOS and the subsequent development of gynecological cancers including uterine, breast, or ovarian cancer.
  
  
  METHODS
  We identified subjects who were diagnosed with PCOS between January 1, 2000, and December 31, 2004, in the Taiwan National Health Insurance (NHI) Research Database. A comparison cohort was constructed for patients without known PCOS who were also matched according to age. All PCOS and control patients were observed until diagnosed with breast cancer, ovarian cancer, or uterine cancer or until death, withdrawal from the NHI system, or December 31, 2009.
  
  
  RESULTS
  The PCOS cohort consisted of 3,566 patients, and the comparison cohort consisted of 14,264 matched control patients without PCOS. The adjusted hazard ratio (HR) of uterine cancer and breast cancer in subjects with PCOS were higher (HR: 8.42 [95% confidence interval: 1.62-43.89] and HR: 1.99 [95% confidence interval: 1.05-3.77], respectively) than that of the controls during the follow-up. With the Monte Carlo method, only the mean adjusted HR of 1,000 comparisons for developing uterine cancer during the follow-up period was greater for the PCOS group than for the control groups (HR: 4.71, 95% confidence interval: 1.57-14.11).
  
  
  CONCLUSIONS
  PCOS might increase the risk of subsequent newly diagnosed uterine cancer. It is critical that further large-scale, well-designed studies be conducted to confirm the association between PCOS and gynecological cancer risk.
authors.affiliation: Department of Psychiatry, Chiayi Branch, Taichung Veterans General Hospital, Chiayi, Taiwan, Republic of China; Department of Information Management, National Chung-Cheng University, Chiayi, Taiwan, Republic of China; Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China; School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China; Department of Obstetrics and Gynecology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan, Republic of China; School of Medicine, Tzu Chi University, Hualien, Taiwan, Republic of China; Department of Psychiatry, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Republic of China.
authors.forename: Cheng-Che
authors.initials: CC
authors.lastname: Shen
authors.affiliation: Department of Psychiatry, Chiayi Branch, Taichung Veterans General Hospital, Chiayi, Taiwan, Republic of China; Department of Information Management, National Chung-Cheng University, Chiayi, Taiwan, Republic of China; Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China; School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China; Department of Obstetrics and Gynecology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan, Republic of China; School of Medicine, Tzu Chi University, Hualien, Taiwan, Republic of China; Department of Psychiatry, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Republic of China.
authors.forename: Albert C
authors.initials: AC
authors.lastname: Yang
authors.affiliation: Department of Psychiatry, Chiayi Branch, Taichung Veterans General Hospital, Chiayi, Taiwan, Republic of China; Department of Information Management, National Chung-Cheng University, Chiayi, Taiwan, Republic of China; Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China; School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China; Department of Obstetrics and Gynecology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan, Republic of China; School of Medicine, Tzu Chi University, Hualien, Taiwan, Republic of China; Department of Psychiatry, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Republic of China.
authors.forename: Jeng-Hsiu
authors.initials: JH
authors.lastname: Hung
authors.affiliation: Department of Psychiatry, Chiayi Branch, Taichung Veterans General Hospital, Chiayi, Taiwan, Republic of China; Department of Information Management, National Chung-Cheng University, Chiayi, Taiwan, Republic of China; Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China; School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China; Department of Obstetrics and Gynecology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan, Republic of China; School of Medicine, Tzu Chi University, Hualien, Taiwan, Republic of China; Department of Psychiatry, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Republic of China.
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Hu
authors.affiliation: Department of Psychiatry, Chiayi Branch, Taichung Veterans General Hospital, Chiayi, Taiwan, Republic of China; Department of Information Management, National Chung-Cheng University, Chiayi, Taiwan, Republic of China; Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China; School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China; Department of Obstetrics and Gynecology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan, Republic of China; School of Medicine, Tzu Chi University, Hualien, Taiwan, Republic of China; Department of Psychiatry, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, Republic of China tsai610913@gmail.com.
authors.forename: Shih-Jen
authors.initials: SJ
authors.lastname: Tsai
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D011159:Population Surveillance; D012189:Retrospective Studies; D012307:Risk Factors; D013624:Taiwan; D014594:Uterine Neoplasms / Q000150:complications / Q000453:epidemiology* / Q000473:pathology
keywords: Breast cancer; Ovarian cancer; Polycystic ovary syndrome; Retrospective cohort study; Uterine cancer