title: Prognostic Factors in an Exercised Model of Chemically-induced Mammary Cancer.
abstract: OBJECTIVE
  Estrogen receptor α (ERα) and Ki-67 are strong prognostic and predictive markers in woman breast cancer. This study aimed to evaluate the immunoexpression of prognostic factor markers ERα, Ki-67 proliferation index (Ki-67 PI) and the mitotic activity index (MAI) in mammary tumors induced by 1-methyl-1-nitrosourea (MNU) in female Sprague-Dawley rats submitted to lifelong exercise training.
  
  
  METHODS
  Thirty female rats were injected with MNU and randomly divided into two groups: sedentary and exercised.
  
  
  RESULTS
  All neoplasms from both groups were ERα-positive with an H-score ≥20. Statistically significant differences were not found in the ERα H-score, Ki-67 PI and MAI between groups. The absolute value of ERα H-score was higher in the exercised group, while the Ki-67 PI and MAI were higher in the sedentary group.
  
  
  CONCLUSIONS
  Tumors from the exercised group were less proliferative and more differentiated, suggesting that long-term exercise training had positive effects on mammary carcinogenesis.
authors.affiliation: Área de Patología, Decanato de Ciencias Veterinarias, Universidad Centroccidental "Lisandro Alvarado", UCLA, Lara, Venezuela Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, Vila Real, Portugal Center for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), UTAD, Vila Real, Portugal.
authors.forename: Antonieta
authors.initials: A
authors.lastname: Alvarado
authors.affiliation: Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, Vila Real, Portugal Center for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), UTAD, Vila Real, Portugal Organic Chemistry, Natural Products and Foodstuffs (QOPNA), Mass Spectrometry Center, Department of Chemistry, University of Aveiro, Aveiro, Portugal.
authors.forename: Ana I
authors.initials: AI
authors.lastname: Faustino-Rocha
authors.affiliation: Organic Chemistry, Natural Products and Foodstuffs (QOPNA), Mass Spectrometry Center, Department of Chemistry, University of Aveiro, Aveiro, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Ferreira
authors.affiliation: School of Life Sciences and Environment (ECVA), UTAD, Vila Real, Portugal.
authors.forename: Rafael
authors.initials: R
authors.lastname: Mendes
authors.affiliation: Center of Investigation and Physical Activity, Heath and Laser (CIAFEL), Faculty of Sports, University of Porto, Porto, Portugal.
authors.forename: José Alberto
authors.initials: JA
authors.lastname: Duarte
authors.affiliation: Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, Vila Real, Portugal Center for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), UTAD, Vila Real, Portugal.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Pires
authors.affiliation: Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, Vila Real, Portugal Department of Zootechnics, School of Agrarian and Veterinary Sciences, UTAD, Vila Real, Portugal.
authors.forename: Bruno
authors.initials: B
authors.lastname: Colaço
authors.affiliation: Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, UTAD, Vila Real, Portugal Center for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), UTAD, Vila Real, Portugal pamo@utad.pt.
authors.forename: Paula A
authors.initials: PA
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D047628:Estrogen Receptor alpha / Q000378:metabolism; D005260:Female; D019394:Ki-67 Antigen / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D010805:Physical Conditioning, Animal; D011379:Prognosis; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D047628:Estrogen Receptor alpha; D019394:Ki-67 Antigen
keywords: 1-methyl-1-nitrosourea; ERα H-Score; Ki-67 proliferation index; mitotic index; rat