title: REG1A expression is an independent factor predictive of poor prognosis in patients with breast cancer.
abstract: BACKGROUND
  Regenerating gene I alpha (REG1A) is a growth factor known to affect pancreatic islet beta cells. Although REG1A expression has also been observed in various malignant tumors, the correlation between REG1A expression and the clinicopathological characteristics of breast cancer and patient prognosis has not been evaluated.
  
  
  METHODS
  Resected breast cancer tissues obtained at surgery from 150 breast cancer patients was stained with anti-REG1A antibody, after which the relative area occupied by stained tumor cells was evaluated under a light microscope and correlated with known clinicopathological factors.
  
  
  RESULTS
  Whereas tumor cells were frequently stained with anti-REG1A antibody, cells from normal breast tissue were not stained. REG1A expression in tumors of breast cancer patients with HER2-positive disease was higher than those with HER2-negative disease (P = .0009). The 10-year disease-specific survival rate among patients with lower levels of REG1A was significantly better than among those with higher levels (P = .0002 by log rank test). Multivariate Cox proportional hazard analyses revealed REG1A (hazard ratio, 2.07; 95% confidence interval, 1.93 to 11.29; P = .0005) and axillary lymph node status (hazard ratio, 4.44; 95% confidence interval, 1.52 to 11.29; P = .0003) to be independent factors affecting the 10-year disease-specific survival rate.
  
  
  CONCLUSIONS
  High levels of REG1A expression within tumors are an independent predictor of poor prognosis in patients with breast cancer.
authors.affiliation: Department of Surgery, Akita University School of Medicine, 1-1-1 Hondo, Akita City, 010-8543, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Minamiya
authors.forename: Naoko
authors.initials: N
authors.lastname: Takahashi
authors.forename: Taku
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Katayose
authors.forename: Aki
authors.initials: A
authors.lastname: Ito
authors.forename: Hajime
authors.initials: H
authors.lastname: Saito
authors.forename: Satoru
authors.initials: S
authors.lastname: Motoyama
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D051847:Lithostathine / Q000378:metabolism*; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D051847:Lithostathine; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C497617:REG1A protein, human