REG1A expression is an independent factor predictive of poor prognosis in patients with breast cancer.
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.
Sasaki
Yasuhiro
Y
Department of Surgery, Akita University School of Medicine, 1-1-1 Hondo, Akita City, 010-8543, Japan.
Minamiya
Yoshihiro
Y
Takahashi
Naoko
N
Nakagawa
Taku
T
Katayose
Yoshihisa
Y
Ito
Aki
A
Saito
Hajime
H
Motoyama
Satoru
S
Ogawa
Jun-ichi
J
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
D014408:Biomarkers, Tumor; D051847:Lithostathine; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C497617:REG1A protein, human