title: Thyroid function alters during neoadjuvant chemotherapy in breast cancer patients: results from the NEOZOTAC trial (BOOG 2010-01).
abstract: This side study investigated the effect of chemotherapy on thyroid function and the extent to which it can predict pathological complete response (pCR) in patients with early breast cancer taking part in NEOZOTAC phase III trial, randomizing between neoadjuvant chemotherapy with or without additional zoledronic acid. Moreover, we examined the impact of thyroid function on toxicity. Serum samples of 38 patients were available for analyses. Free thyroxin (fT4) and thyroid stimulating hormone (TSH) levels were compared between baseline and before the 6th cycle and between subjects with and without pCR. The relation between toxicity and the variation in fT4 and TSH levels during chemotherapy was tested. Samples at baseline and before the 6th cycle were available for 31 and 21 patients, respectively. The mean baseline fT4 level was 16.0 pmol/L and TSH level 1.11 mU/L, and these did not differ between both arms at each time point. During six cycles of chemotherapy, fT4 levels decreased (p = 0.0001), and TSH levels increased significantly (p = 0.019). Interestingly, the decrease of fT4 was significantly greater in patients without nausea, vomiting, or neuropathy, than in patients with those side effects (p = 0.037, p = 0.043, and p = 0.050, respectively). Baseline TSH levels tended to be higher in patients with pCR (p = 0.035 univariate analysis and p = 0.074 multivariate analysis). Chemotherapy blunts thyroid function, which was associated with less side effects. These data urge further evaluation of the effects of thyroid function on toxicity and outcome of breast cancer therapy.
authors.affiliation: Department of Clinical Oncology, Leiden University Medical Center, Abinusdreef 2, P.O. Box 9600, 2300 RC, Leiden, The Netherlands, s.de_groot2@lumc.nl.
authors.forename: S
authors.initials: S
authors.lastname: de Groot
authors.forename: L G M
authors.initials: LG
authors.lastname: Janssen
authors.forename: A
authors.initials: A
authors.lastname: Charehbili
authors.forename: E M
authors.initials: EM
authors.lastname: Dijkgraaf
authors.forename: V T H B M
authors.initials: VT
authors.lastname: Smit
authors.forename: L W
authors.initials: LW
authors.lastname: Kessels
authors.forename: A
authors.initials: A
authors.lastname: van Bochove
authors.forename: H W M
authors.initials: HW
authors.lastname: van Laarhoven
authors.forename: E
authors.initials: E
authors.lastname: Meershoek-Klein Kranenbarg
authors.forename: A E
authors.initials: AE
authors.lastname: van Leeuwen-Stok
authors.forename: C J H
authors.initials: CJ
authors.lastname: van de Velde
authors.forename: H
authors.initials: H
authors.lastname: Putter
authors.forename: J W R
authors.initials: JW
authors.lastname: Nortier
authors.forename: J J M
authors.initials: JJ
authors.lastname: van der Hoeven
authors.forename: H
authors.initials: H
authors.lastname: Pijl
authors.forename: J R
authors.initials: JR
authors.lastname: Kroep
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D013972:Thyrotropin; D013974:Thyroxine