title: Prognostic role of human epidermal growth factor receptor 2 status in premenopausal early breast cancer treated with adjuvant tamoxifen.
abstract: BACKGROUND
  Hormone therapy is the most prescribed systemic therapy for patients with breast cancer (BC). Some patients fail to respond to tamoxifen; one pathway seems to involve human epidermal growth factor receptor 2 (HER2) overexpression. To better understand this matter, we reviewed our single-center experience of premenopausal patients who were chemotherapy naive and treated with 5 years of tamoxifen for early-stage BC by focusing on estrogen receptor (ER), progesterone receptor, HER2 status, and Ki-67 proliferative index.
  
  
  METHODS
  We reviewed 425 patients treated with tamoxifen for early-stage BC. Previous solid tumors, age less than 18 years, BC recurrences or contralateral tumor, tamoxifen discontinuation, adjuvant chemotherapy, and a follow-up shorter than 6 months were considered exclusions criteria of the study.
  
  
  RESULTS
  At a mean follow-up of 8.1 years, the mean (SD) time to local relapse was 6.7 ± 3.6 years; range, 2.0-10.7 years), whereas the mean (SD) time to distant metastases was 4.7 ± 2.3 years; range, 2.2-8.8 years). HER2 status did not influence local relapse-free survival (log-rank test, 0.40), distant metastases-free survival (log-rank test, 0.72), and overall survival rate (log-rank test, 0.87).
  
  
  CONCLUSIONS
  Resistance to tamoxifen is a complex trait, and its pathway is still unclear; in patients with BC, a multidisciplinary approach is highly recommended. In our experience, we did not find a statistically significant difference in tamoxifen treatment efficacy according to HER2 status.
authors.affiliation: Department of Radiation-Oncology, University of Florence, Florence, Italy. icro.meattini@unifi.it
authors.forename: Icro
authors.initials: I
authors.lastname: Meattini
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Livi
authors.forename: Calogero
authors.initials: C
authors.lastname: Saieva
authors.forename: Davide
authors.initials: D
authors.lastname: Franceschini
authors.forename: Vieri
authors.initials: V
authors.lastname: Scotti
authors.forename: Monica
authors.initials: M
authors.lastname: Mangoni
authors.forename: Mauro
authors.initials: M
authors.lastname: Loi
authors.forename: Lucia
authors.initials: L
authors.lastname: Di Brina
authors.forename: Giacomo
authors.initials: G
authors.lastname: Zei
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Bonomo
authors.forename: Daniela
authors.initials: D
authors.lastname: Greto
authors.forename: Elena
authors.initials: E
authors.lastname: Gelain
authors.forename: Jacopo
authors.initials: J
authors.lastname: Nori
authors.forename: Luis Jose
authors.initials: LJ
authors.lastname: Sanchez
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Orzalesi
authors.forename: Simonetta
authors.initials: S
authors.lastname: Bianchi
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Biti
mesh_terms: D000328:Adult; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D018275:Carcinoma, Lobular / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D017697:Premenopause; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D015996:Survival Rate; D013629:Tamoxifen / Q000627:therapeutic use*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013629:Tamoxifen; C508053:ERBB2 protein, human
keywords: Early breast cancer; Hormone resistance; Human epidermal growth factor receptor 2 status; Prognostic factors; Tamoxifen