title: Biomarkers of fatigue related to adjuvant chemotherapy for breast cancer: evaluation of plasma and lymphocyte expression.
abstract: BACKGROUND
  Fatigue is common in cancer patients receiving adjuvant chemotherapy. To further understand the mechanism of fatigue and search for potential biomarkers, we conducted this prospective study. Methods We enrolled breast cancer (BC) patients before their first adjuvant Adriamycin-based chemotherapy cycle. Patients responded to the brief fatigue inventory (BFI) and Chalder fatigue questionnaires and had their blood drawn for both plasma evaluation and evaluation of the peripheral mononuclear cell fraction (PMNCF) mRNA expression of various biomarkers. We evaluated FSH, LH, estradiol, DHEA, DHEAS, IL6, IL2, ILIRA, IL1β, CRP, Cortisol in the plasma and IL2, IL10, IL6, TGF-β, KLRC1, TNF, BTP, SNCA, SOD1, BLNK, PTGS2 and INF γ expression in the PMNCF.
  
  
  RESULTS
  11 patients did not exhibit an increase in their BFI scores and served as controls, whereas 32 patients exhibited an increase in their BFI scores compared with the baseline scores. From the biomarkers we evaluated in the PMNCF, the only one significantly associated with fatigue was TGF-β (p = 0.0343), while there was a trend towards significance with KLRC1 (p = 0.0627). We observed no evidence of significant associations of any plasma biomarkers with the development of fatigue. However when we analyzed patients with more severe fatigue, plasma IL1-RA levels correlated directly with higher fatigue scores (p = 0.0136).
  
  
  CONCLUSIONS
  We conclude that fatigue induced by chemotherapy in BC patients is associated with changes in IL1-ra plasma levels and in TGF-β lymphocyte expression. Its mechanism may be different than that observed in long-term BC survivors or that induced by radiation therapy.
  
  
  BACKGROUND
  NCT02041364 [ClinicalTrials.gov].
authors: Discipline of Oncology and Hematology, ABC Foundation School of Medicine, Av. Príncipe de Gales, 821, Santo André, 09060-650 SP Brazil.
authors: Felipe M
authors: FM
authors: Cruz
authors: Discipline of Oncology and Hematology, ABC Foundation School of Medicine, Av. Príncipe de Gales, 821, Santo André, 09060-650 SP Brazil.
authors: Bruna A
authors: BA
authors: Munhoz
authors: Discipline of Oncology and Hematology, ABC Foundation School of Medicine, Av. Príncipe de Gales, 821, Santo André, 09060-650 SP Brazil.
authors: Beatriz Ca
authors: BC
authors: Alves
authors: Discipline of Oncology and Hematology, ABC Foundation School of Medicine, Av. Príncipe de Gales, 821, Santo André, 09060-650 SP Brazil.
authors: Flavia S
authors: FS
authors: Gehrke
authors: Discipline of Oncology and Hematology, ABC Foundation School of Medicine, Av. Príncipe de Gales, 821, Santo André, 09060-650 SP Brazil.
authors: Fernando LA
authors: FL
authors: Fonseca
authors: Discipline of Oncology and Hematology, ABC Foundation School of Medicine, Av. Príncipe de Gales, 821, Santo André, 09060-650 SP Brazil.
authors: Renata K
authors: RK
authors: Kuniyoshi
authors: Discipline of Oncology and Hematology, ABC Foundation School of Medicine, Av. Príncipe de Gales, 821, Santo André, 09060-650 SP Brazil.
authors: Daniel
authors: D
authors: Cubero
authors: Department of Surgery, University of Rochester, Rochester, 14642 NY USA.
authors: Luke J
authors: LJ
authors: Peppone
authors: Discipline of Oncology and Hematology, ABC Foundation School of Medicine, Av. Príncipe de Gales, 821, Santo André, 09060-650 SP Brazil.
authors: Auro
authors: A
authors: Del Giglio
keywords: Biomarkers; Breast Cancer; Chemotherapy; Fatigue; IL1-ra; TGF-β