title: The alterations of serum FGF-21 levels, metabolic and body composition in early breast cancer patients receiving adjuvant endocrine therapy.
abstract: BACKGROUND
  In early breast cancer patients, the effects of hormonal therapy (tamoxifen and aromatase inhibitors) on plasma fibroblast growth factor 21 (FGF-21), lipid levels and body composition have not yet been investigated. Therefore, we aimed to analyze the relationship between FGF-21 and body composition as well as the effects of tamoxifen and aromatase inhibitors on plasma lipid levels, FGF-21, and body composition.
  
  
  METHODS
  A total of 72 patients were treated with either tamoxifen or aromatase inhibitors due to their menopausal status after adjuvant radiotherapy. Each patient was followed-up over a period of 1 year. Changes in body composition and serum lipid profile, glucose and FGF-21 levels were evaluated. We recorded the type of hormonal therapy, body mass index, waist-to-hip ratio, lipid profile, and FGF-21 levels both at the beginning and after 12 months.
  
  
  RESULTS
  There was a statistically significant decrease in serum FGF-21 levels after 12 months of adjuvant endocrine therapy (46 ± 19.21 pg/ml vs. 30.99 ± 13.81 pg/ml, p< 0.001). Total body water (p< 0.001), serum glucose (p= 0.036) and triglyceride levels (p< 0.001) also exhibited a significant decrease. The decreases in total cholesterol and low-density lipoprotein were not statistically significant. Likewise, high-density lipoprotein increased after adjuvant endocrine therapy, although it did not reach statistical significance. The changes in body composition, glucose, lipid profile and FGF-21 were similar in tamoxifen and aromatase inhibitor groups. A positive correlation was found between basal weight, fat mass, fat-free mass and serum FGF-21 levels; however, the correlation was maintained only for the fat-free mass at the 12th month.
  
  
  CONCLUSIONS
  As part of the present study, we suggest that both tamoxifen and aromatase inhibitors can reduce FGF-21 levels independently of body compositions, and these drugs can provide antihyperlipidemic, antidiabetic and cardio-protective effects. We also recommend that serum FGF-21 level can be utilized as a tumor biomarker in early-stage breast cancer and for monitoring purposes. FGF-21 levels may help physicians estimate prognosis, too. Further studies with larger populations may shed light on the role of FGF-21 in breast cancer.
authors.affiliation: Department of Medical Oncology, Manisa State Hospital, Manisa, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Akyol
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Alacacioglu
authors.affiliation: Department of Biochemistry, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Leyla
authors.initials: L
authors.lastname: Demir
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Yuksel
authors.initials: Y
authors.lastname: Kucukzeybek
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Yasar
authors.initials: Y
authors.lastname: Yildiz
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Zehra
authors.initials: Z
authors.lastname: Gumus
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Mete
authors.initials: M
authors.lastname: Kara
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Tarik
authors.initials: T
authors.lastname: Salman
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Umut
authors.initials: U
authors.lastname: Varol
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Halil
authors.initials: H
authors.lastname: Taskaynatan
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Utku
authors.initials: U
authors.lastname: Oflazoglu
authors.affiliation: Department of Medical Oncology, Izmir Katip Celebi University Ataturk Training and Research Hospital, Izmir, Turkey.
authors.forename: Vedat
authors.initials: V
authors.lastname: Bayoglu
authors.affiliation: Institute of Oncology, Dokuz Eylul University, Izmir, Turkey.
authors.forename: Mustafa Oktay
authors.initials: MO
authors.lastname: Tarhan
mesh_terms: D000328:Adult; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage; D047072:Aromatase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects; D001823:Body Composition; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000097:blood* / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects; D008076:Cholesterol, HDL / Q000097:blood; D005260:Female; D005346:Fibroblast Growth Factors / Q000097:blood*; D006801:Humans; D008055:Lipids; D008875:Middle Aged; D009367:Neoplasm Staging; D013629:Tamoxifen / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D008076:Cholesterol, HDL; D008055:Lipids; C414620:fibroblast growth factor 21; D013629:Tamoxifen; D005346:Fibroblast Growth Factors
keywords: Breast cancer; aromatase inhibitors; glucose metabolism; lipid metabolism; serum FGF 21; tamoxifen