title: Overdiagnosis of thyroid cancer in the Marne and Ardennes Departments of France from 1975 to 2014.
abstract: OBJECTIVE
  Incidence of thyroid cancer has increased considerably in France in recent years, but the mortality rate has declined only slightly. Part of this increased incidence could be attributable to overdiagnosis. We aimed to estimate the contribution of overdiagnosis to the incidence of papillary thyroid cancer.
  
  
  METHODS
  Incidence rates were calculated based on data from the specialised Marnes-Ardennes thyroid cancer registry, for cancers diagnosed between 1975 and 2014, by age category and by five-year period. The population was divided into two groups according to pTNM classification at diagnosis (i.e. localised or invasive). Overdiagnosis was defined as the difference in incidence rates between the invasive cancer and localised cancer groups. This rate was then divided by the incidence rate in the localised cancer group for the most recent period (2010-2014) to obtain the proportion of cancers attributable to overdiagnosis.
  
  
  RESULTS
  In total, 2008 patients were included. The proportion of incidence attributable to overdiagnosis for the period 2010-2014 was estimated at 7 and 62% in men and women aged < 50 years respectively, and at 65 and 73% respectively in men and women aged ≥ 50 years.
  
  
  CONCLUSIONS
  We observed a high proportion of cancers attributable to overdiagnosis. This finding raises the issue of patient management, with the risk of overtreatment, and the repercussions on quality of life for patients diagnosed with cancer.
authors.affiliation: Thyroid Cancer Registry, Institut Jean-Godinot, 51100 Reims, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Saint-Martin
authors.affiliation: EA 3757, University of Reims Champagne-Ardenne, Faculty of Medicine, 51095 Reims, France; Department of Research and Innovation, Reims Teaching Hospitals, Robert-Debré Hospital, rue du Général-Koenig, 51092 Reims, France. Electronic address: mdrame@chu-reims.fr.
authors.forename: Moustapha
authors.initials: M
authors.lastname: Dramé
authors.affiliation: Thyroid Cancer Registry, Institut Jean-Godinot, 51100 Reims, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Dabakuyo
authors.affiliation: EA 3757, University of Reims Champagne-Ardenne, Faculty of Medicine, 51095 Reims, France; Department of Research and Innovation, Reims Teaching Hospitals, Robert-Debré Hospital, rue du Général-Koenig, 51092 Reims, France.
authors.forename: Lukshe
authors.initials: L
authors.lastname: Kanagaratnam
authors.affiliation: Côte-d'Or Breast Cancer Registry, Georges-François-Leclerc Center, 21000 Dijon, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Arveux
authors.affiliation: Thyroid Cancer Registry, Institut Jean-Godinot, 51100 Reims, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Schvartz
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000175:diagnosis / Q000453:epidemiology; D002291:Carcinoma, Papillary; D015331:Cohort Studies; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D000069342:Medical Overuse / Q000706:statistics & numerical data; D008875:Middle Aged; D012042:Registries; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000453:epidemiology*
keywords: Glande thyroïdienne; Incidence; Néoplasmes thyroïdiens; Overdiagnosis; Surdiagnostic; Thyroid gland; Thyroid neoplasms