title: Characteristics of contralateral carcinomas in patients with differentiated thyroid cancer larger than 1 cm.
abstract: OBJECTIVE
  Traditionally, total thyroidectomy has been advocated for patients with tumors larger than 1 cm. However, according to the ATA and NCCN guidelines (2015, USA), patients with tumors up to 4 cm are now eligible for lobectomy. A rationale for adhering to total thyroidectomy might be the presence of contralateral carcinomas. The purpose of this study was to describe the characteristics of contralateral carcinomas in patients with differentiated thyroid cancer (DTC) larger than 1 cm.
  
  
  METHODS
  A retrospective study was performed including patients from 17 centers in 5 countries. Adults diagnosed with DTC stage T1b-T3 N0-1a M0 who all underwent a total thyroidectomy were included. The primary endpoint was the presence of a contralateral carcinoma.
  
  
  RESULTS
  A total of 1313 patients were included, of whom 426 (32 %) had a contralateral carcinoma. The contralateral carcinomas consisted of 288 (67 %) papillary thyroid carcinomas (PTC), 124 (30 %) follicular variant of a papillary thyroid carcinoma (FvPTC), 5 (1 %) follicular thyroid carcinomas (FTC), and 3 (1 %) Hürthle cell carcinomas (HTC). Ipsilateral multifocality was strongly associated with the presence of contralateral carcinomas (OR 2.62). Of all contralateral carcinomas, 82 % were ≤10 mm and of those 99 % were PTC or FvPTC. Even if the primary tumor was a FTC or HTC, the contralateral carcinoma was (Fv)PTC in 92 % of cases.
  
  
  CONCLUSIONS
  This international multicenter study performed on patients with DTC larger than 1 cm shows that contralateral carcinomas occur in one third of patients and, independently of primary tumor subtype, predominantly consist of microPTC.
authors.affiliation: University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
authors.forename: Lutske
authors.identifier: http://orcid.org/0000-0002-3186-2805
authors.initials: L
authors.lastname: Lodewijk
authors.affiliation: University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
authors.forename: Wouter P
authors.initials: WP
authors.lastname: Kluijfhout
authors.affiliation: University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
authors.forename: Jakob W
authors.initials: JW
authors.lastname: Kist
authors.affiliation: University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
authors.forename: Inge
authors.initials: I
authors.lastname: Stegeman
authors.affiliation: University Medical Center Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
authors.forename: John T M
authors.initials: JT
authors.lastname: Plukker
authors.affiliation: Academic Medical Center Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
authors.forename: Els J
authors.initials: EJ
authors.lastname: Nieveen van Dijkum
authors.affiliation: VU Medical Center, De Boelelaan 1117, 1081 HZ, Amsterdam, The Netherlands.
authors.forename: H Jaap
authors.initials: HJ
authors.lastname: Bonjer
authors.affiliation: Maastricht University Medical Center, P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.
authors.forename: Nicole D
authors.initials: ND
authors.lastname: Bouvy
authors.affiliation: Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
authors.forename: Abbey
authors.initials: A
authors.lastname: Schepers
authors.affiliation: Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands.
authors.forename: Johannes H W
authors.initials: JH
authors.lastname: de Wilt
authors.affiliation: Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands.
authors.forename: Romana T
authors.initials: RT
authors.lastname: Netea-Maier
authors.affiliation: Netherlands Cancer Institute, Plesmanlaan 121 - 123, 1066 CX, Amsterdam, The Netherlands.
authors.forename: Jos A
authors.initials: JA
authors.lastname: van der Hage
authors.affiliation: Erasmus Medical Center, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands.
authors.forename: Jacobus W A
authors.initials: JW
authors.lastname: Burger
authors.affiliation: University of California San Francisco Medical Center, 505 Parnassus Ave, San Francisco, CA, 94143, USA.
authors.forename: Gavin
authors.initials: G
authors.lastname: Ho
authors.affiliation: University of California San Francisco Medical Center, 505 Parnassus Ave, San Francisco, CA, 94143, USA.
authors.forename: Wayne S
authors.initials: WS
authors.lastname: Lee
authors.affiliation: University of California San Francisco Medical Center, 505 Parnassus Ave, San Francisco, CA, 94143, USA.
authors.forename: Wen T
authors.initials: WT
authors.lastname: Shen
authors.affiliation: Weill Cornell Medical Center, 525 E 68th St, New York, NY, 10065, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Aronova
authors.affiliation: Weill Cornell Medical Center, 525 E 68th St, New York, NY, 10065, USA.
authors.forename: Rasa
authors.initials: R
authors.lastname: Zarnegar
authors.affiliation: McGill University Health Centre, 1650 Cedar Avenue, Montreal, Quebec, H3G 1A4, Canada.
authors.forename: Cassandre
authors.initials: C
authors.lastname: Benay
authors.affiliation: McGill University Health Centre, 1650 Cedar Avenue, Montreal, Quebec, H3G 1A4, Canada.
authors.forename: Elliot J
authors.initials: EJ
authors.lastname: Mitmaker
authors.affiliation: Endocrine Surgery Unit, University of Sydney, Camperdown, NSW, 2006, Australia.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Sywak
authors.affiliation: Endocrine Surgery Unit, University of Sydney, Camperdown, NSW, 2006, Australia.
authors.forename: Ahmad M
authors.initials: AM
authors.lastname: Aniss
authors.affiliation: Endocrine Surgery Unit, University of Sydney, Camperdown, NSW, 2006, Australia.
authors.forename: Schelto
authors.initials: S
authors.lastname: Kruijff
authors.affiliation: The University of Chicago Medical Center, 5841 S Maryland Ave, Chicago, IL, 60637, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: James
authors.affiliation: The University of Chicago Medical Center, 5841 S Maryland Ave, Chicago, IL, 60637, USA.
authors.forename: Raymon H
authors.initials: RH
authors.lastname: Grogan
authors.affiliation: Centre Hospitalier Universitaire de Nancy, 29 Avenue du Maréchal de Lattre de Tassigny, 54000, Nancy, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Brunaud
authors.affiliation: Centre Hospitalier Universitaire de Nancy, 29 Avenue du Maréchal de Lattre de Tassigny, 54000, Nancy, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Hoch
authors.affiliation: Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA.
authors.forename: Chiara
authors.initials: C
authors.lastname: Pandolfi
authors.affiliation: Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Ruan
authors.affiliation: The University of Arizona Medical Center, 3838 N Campbell Ave, Tucson, AZ, 85719, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Jones
authors.affiliation: The University of Arizona Medical Center, 3838 N Campbell Ave, Tucson, AZ, 85719, USA.
authors.forename: Marlon A
authors.initials: MA
authors.lastname: Guerrero
authors.affiliation: University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
authors.forename: Gerlof D
authors.initials: GD
authors.lastname: Valk
authors.affiliation: University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
authors.forename: Inne H M
authors.initials: IH
authors.lastname: Borel Rinkes
authors.affiliation: University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands. mvriens@umcutrecht.nl.|Department of Surgery (G.04.228), University Medical Center Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands. mvriens@umcutrecht.nl.
authors.forename: Menno R
authors.initials: MR
authors.lastname: Vriens
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009378:Neoplasms, Multiple Primary / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D047368:Tumor Burden
keywords: Contralateral carcinoma; Differentiated thyroid carcinoma; Papillary microcarcinoma; Surgical strategy