title: Extreme hypothyroidism associated with sunitinib treatment for metastatic renal cancer.
abstract: Although thyroid abnormalities are reported with the use of tyrosine kinase inhibitors, patients rarely require replacement therapy. The initial multicentre studies of sunitinib for metastatic renal cancer did not report hypothyroidism in fatigued patients, and thyroid tests were not  routinely monitored. More recent studies, however, suggest that up to 70% of patients develop thyroid test abnormalities during treatment with sunitinib. Despite these concerns, the clinical relevance of sunitinib-induced hypothyroidism is uncertain since thyroid gland recovery is the norm  in most patients. We report a case of a patient with metastatic papillary renal cell cancer on combination anti-angiogenic therapy with sunitinib, who developed unusually high thyroid stimulating hormone levels and severe symptoms despite receiving L-thyroxine. Our case also illustrates the  complexity of managing sunitinib-associated thyroid dysfunction, which may be accompanied by transient thyroiditis, hyperthyroidism, and profound hypothyroidism.
authors.affiliation: Department of Palliative Care and Rehabilitation Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. edelfabbro@vcu.edu
authors.forename: Egidio
authors.initials: E
authors.lastname: Del Fabbro
authors.forename: Rony
authors.initials: R
authors.lastname: Dev
authors.forename: Maria E
authors.initials: ME
authors.lastname: Cabanillas
authors.forename: Naifa L
authors.initials: NL
authors.lastname: Busaidy
authors.forename: EdenMae C
authors.initials: EC
authors.lastname: Rodriguez
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bruera
mesh_terms: D000328:Adult; D020533:Angiogenesis Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000188:drug therapy / Q000556:secondary; D002292:Carcinoma, Renal Cell / Q000097:blood / Q000188:drug therapy* / Q000556:secondary; D004351:Drug Resistance; D017809:Fatal Outcome; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000139:chemically induced* / Q000188:drug therapy / Q000503:physiopathology; D007211:Indoles / Q000009:adverse effects* / Q000627:therapeutic use; D007680:Kidney Neoplasms / Q000097:blood / Q000188:drug therapy*; D008113:Liver Neoplasms / Q000188:drug therapy / Q000556:secondary; D011758:Pyrroles / Q000009:adverse effects* / Q000627:therapeutic use; D012720:Severity of Illness Index; D000077210:Sunitinib; D013961:Thyroid Gland / Q000187:drug effects* / Q000503:physiopathology; D013974:Thyroxine / Q000627:therapeutic use
chemical_list: D020533:Angiogenesis Inhibitors; D007211:Indoles; D011758:Pyrroles; D013974:Thyroxine; D000077210:Sunitinib