title: A prospective longitudinal study on endocrine dysfunction following treatment of laryngeal or hypopharyngeal carcinoma.
abstract: OBJECTIVE
  The incidences of hypo(para)thyroidism were assessed prospectively in 137 consecutive patients with laryngeal (84.7%) or hypopharyngeal (15.3%) carcinoma who were treated with surgery and/or radiotherapy between 2004 and 2006.
  
  
  METHODS
  Laboratory studies were performed in patients before primary or salvage treatment of a laryngeal or hypopharyngeal carcinoma and were repeated 6, 12, 18 and 24months after treatment. All patients were evaluated for the development of hypo(para)thyroidism, and the presence of autoantibodies. The association of hypothyroidism was analyzed against several patient parameters including tumor and treatment characteristics.
  
  
  RESULTS
  The incidence of hypothyroidism following treatment of laryngeal and hypopharyngeal carcinoma was 47.4%: 27.7% subclinical hypothyroidism and 19.7% clinical hypothyroidism. The median time to develop hypothyroidism was 10months. The incidence of hypoparathyroidism was 7.3%. Univariate analysis showed that patients with laryngectomy, hemithyroidectomy, neck dissection, paratracheal lymph node dissection and radiotherapy had a higher risk of developing hypothyroidism. Multivariate analysis showed laryngectomy, hemithyroidectomy, neck dissection and age to be predictive factors for the development of hypothyroidism. The combination of surgery and radiotherapy increased this risk. Hemithyroidectomy was the most important risk factor.
  
  
  CONCLUSIONS
  The incidence rate of hypothyroidism after treatment for laryngeal or hypopharyngeal cancer in this largest prospective study is high (47.4%), especially after combination treatment. Based on the intervals between treatment and the development of hypothyroidism, thyroid testing before treatment, every 3months during the first year, every 6months the second year and annually thereafter is recommended as screening procedure.
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Annalisa M
authors.initials: AM
authors.lastname: Lo Galbo
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Kuik
authors.affiliation: Department of Internal Medicine, Endocrine Section, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Lips
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: B Mary E
authors.initials: BME
authors.lastname: von Blomberg
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands; Department of Oral and Maxillofacial Surgery and Oral Pathology, Academic Centre for Dentistry Amsterdam (ACTA), VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bloemena
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: C René
authors.initials: CR
authors.lastname: Leemans
authors.affiliation: Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: r.bree@vumc.nl.
authors.forename: Remco
authors.initials: R
authors.lastname: deBree
mesh_terms: D004702:Endocrine Glands / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000601:surgery*; D007822:Laryngeal Neoplasms / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies
keywords: Hypopharyngeal carcinoma; Hypothyroidism; Laryngeal carcinoma; Radiotherapy; Surgery