title: Sunitinib-induced thyrotoxicosis - a not so rare entity.
abstract: OBJECTIVE
  The tyrosine kinase inhibitor (TKI) sunitinib malate is nowadays a standard first-line treatment option for patients with metastatic clear-cell renal cell carcinoma (mRCC). The aim of this study was to evaluate the incidence and clinical course of thyrotoxicosis in our cohort of patients treated with sunitinib.
  
  
  METHODS
  Medical records of all patients treated with first-line sunitinib for mRCC at our Institution between November 2008 and March 2014 were retrospectively reviewed. Thyroid function was assessed after every 2 cycles of therapy, during the 2 weeks off period.
  
  
  RESULTS
  Out of the 62 included patients, hypothyroidism has developed during therapy in 12 patients (19%) and it was preceded by thyrotoxicosis in 2 (3.2%).
  
  
  CONCLUSIONS
  Sunitinib-induced thyrotoxicosis (SIT), a not so rare entity, was followed by hypothyroidism. The patterns of occurrence and possible significance of SIT, as predictive marker of better treatment response to sunitinib, need to be validated in further studies.
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Centre "Sestre Milosrdnice", Zagreb, Croatia.
authors.forename: Marijana
authors.initials: M
authors.lastname: Jazvić
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Centre "Sestre Milosrdnice", Zagreb, Croatia.
authors.forename: Marin
authors.initials: M
authors.lastname: Prpić
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Centre "Sestre Milosrdnice", Zagreb, Croatia.
authors.forename: Tomislav
authors.initials: T
authors.lastname: Jukić
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Centre "Sestre Milosrdnice", Zagreb, Croatia.
authors.forename: Jure
authors.initials: J
authors.lastname: Murgić
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Centre "Sestre Milosrdnice", Zagreb, Croatia.
authors.forename: Blanka
authors.initials: B
authors.lastname: Jakšić
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Centre "Sestre Milosrdnice", Zagreb, Croatia davor.kust@kbcsm.hr.
authors.forename: Davor
authors.initials: D
authors.lastname: Kust
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Centre "Sestre Milosrdnice", Zagreb, Croatia.
authors.forename: Angela
authors.initials: A
authors.lastname: Prgomet
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Centre "Sestre Milosrdnice", Zagreb, Croatia.
authors.forename: Ante
authors.initials: A
authors.lastname: Bolanča
authors.affiliation: Department of Oncology and Nuclear Medicine, University Hospital Centre "Sestre Milosrdnice", Zagreb, Croatia.
authors.forename: Zvonko
authors.initials: Z
authors.lastname: Kusić
mesh_terms: D000328:Adult; D020533:Angiogenesis Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D002292:Carcinoma, Renal Cell / Q000188:drug therapy; D017809:Fatal Outcome; D006801:Humans; D007211:Indoles / Q000009:adverse effects* / Q000627:therapeutic use; D007680:Kidney Neoplasms / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D011758:Pyrroles / Q000009:adverse effects* / Q000627:therapeutic use; D012189:Retrospective Studies; D000077210:Sunitinib; D013971:Thyrotoxicosis / Q000139:chemically induced / Q000175:diagnosis*
chemical_list: D020533:Angiogenesis Inhibitors; D007211:Indoles; D011758:Pyrroles; D000077210:Sunitinib
keywords: Renal cell carcinoma; hypothyroidism; levothyroxine substitution therapy; sunitinib; thiamazole antithyroid therapy; thyrotoxicosis