Anterior Gradient 2 is a Poor Outcome Indicator in Luminal Breast Cancer
Maribel D Lacambra1, Julia Y S Tsang1, Yun-Bi Ni1
1Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.
Background:
Recent data have shown anterior gradient 2 (AGR2) to be a novel oncogene overexpressed in luminal breast cancers. However, many studies only focused on its relationship with treatment resistance, and the clinical relevance of AGR2 has not been widely evaluated.
Methods:
AGR2 expression in a cohort of breast cancer was correlated with the clinicopathologic features, biomarker expression, and patient survival.
Results:
AGR2 expression correlated with lower grade (p = 0.002) and absence of necrosis (p = 0.001) and was most highly expressed in luminal cancers (p < 0.001). Correspondingly, AGR2 correlated positively with estrogen receptor, progesterone receptor, and androgen receptor (p < 0.001) and negatively with epidermal growth factor receptor (p =0.002) and CK5/6 (p < 0.001). AGR2 was an independent unfavorable disease-free survival prognostic factor in patients with hormone therapy (hazard ratio 2.537, p = 0.023). Interestingly, it was also an independent adverse disease-free survival prognostic factor in node-positive luminal cancers (hazard ratio 3.381, p = 0.016). AGR2 expression was higher in nodal metastasis than the corresponding primary tumors in luminal cancers (p= 0 .023).
Conclusions:
The prognostic impact of AGR2 expression could be related to treatment outcome in estrogen receptor-positive breast cancers and/or its metastasis-promoting effects. It could be an important tumor biomarker and negative prognostic factor potentially exploitable in clinical practice.
