title: Impact of levonorgestrel-releasing intrauterine system use on the cancer risk of the ovary and fallopian tube.
abstract: BACKGROUND
  Levonorgestrel-releasing intrauterine system (LNG-IUS) is used for contraception and heavy menstrual bleeding. A long-term hormone therapy can modify the risk of gynecologic cancers. Little is known about the impact of LNG-IUS use on the risk for invasive and borderline ovarian tumor subtypes or for primary fallopian tube carcinoma. We examined the associations of LNG-IUS use with these tumors.
  
  
  METHODS
  We identified from the national Medical Reimbursement Registry of Finland the women aged 30-49 years who had used LNG-IUS for menorrhagia in 1994-2007, and from the Finnish Cancer Registry ovarian cancers and primary fallopian tube carcinomas diagnosed before the age of 55 and by the end of 2013.
  
  
  RESULTS
  A total of 77 invasive ovarian cancers and seven primary fallopian tube carcinoma cases were diagnosed in a cohort of 93 843 LNG-IUS users during the follow-up of 1 083 126 women-years. The LNG-IUS users had decreased risk for both invasive ovarian cancer [standardized incidence ratio (SIR) 0.59, 95% confidence interval (CI) 0.47-0.73] and for borderline ovarian tumors (SIR 0.76, 95% CI 0.57-0.99) as compared to the background population. The risk of primary fallopian tube carcinoma was not increased (SIR 1.22, 95% CI 0.49-2.50). Decreased risks for mucinous (SIR 0.49, 95% CI 0.24-0.87), endometrioid (SIR 0.55, 95% CI 0.28-0.98), and serous ovarian carcinomas (SIR 0.75, 95% CI 0.55-0.99) were seen in LNG-IUS users.
  
  
  CONCLUSIONS
  LNG-IUS use associated with decreased risk for both invasive and borderline ovarian tumors. The incidence of primary fallopian tube carcinoma did not significantly differ between LNG-IUS users and the background population.
authors.affiliation: a Department of Obstetrics and Gynecology , Hyvinkää Hospital , Hyvinkää , Finland.
authors.forename: Tuuli
authors.initials: T
authors.lastname: Soini
authors.affiliation: a Department of Obstetrics and Gynecology , Hyvinkää Hospital , Hyvinkää , Finland.
authors.forename: Ritva
authors.initials: R
authors.lastname: Hurskainen
authors.affiliation: b Department of Obstetrics and Gynecology , Turku University Hospital , Turku , Finland.|c University of Turku , Turku , Finland.
authors.forename: Seija
authors.initials: S
authors.lastname: Grénman
authors.affiliation: d School of Medicine, University of Tampere, University of Tampere , Finland.|e Department of Obstetrics and Gynecology , Tampere University Hospital , Tampere , Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Mäenpää
authors.affiliation: f Department of Obstetrics and Gynecology , Helsinki University Hospital , Helsinki , Finland.|g University of Helsinki , Helsinki , Finland.
authors.forename: Jorma
authors.initials: J
authors.lastname: Paavonen
authors.affiliation: h School of Health Sciences, University of Tampere, University of Tampere , Tampere , Finland.|i Finnish Cancer Registry , Institute for Statistical and Epidemiological Cancer Research , Helsinki , Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Pukkala
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000009:adverse effects*; D005185:Fallopian Tube Neoplasms / Q000139:chemically induced* / Q000453:epidemiology / Q000473:pathology; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D007436:Intrauterine Devices, Medicated; D016912:Levonorgestrel / Q000008:administration & dosage* / Q000009:adverse effects*; D008595:Menorrhagia / Q000188:drug therapy; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000139:chemically induced* / Q000453:epidemiology / Q000473:pathology; D012307:Risk Factors
chemical_list: D003271:Contraceptive Agents, Female; D016912:Levonorgestrel