Prognostic value of nuclear hepatoma-derived growth factor (HDGF) localization in patients with breast cancer

Hepatoma-derived growth factor (HDGF) plays an important role in tumor progression. Highly expressed HDGF has been found to indicate poor prognosis in many cancers. However, no information is available regarding the prognostic value of nuclear or cytoplasmic HDGF staining level in breast cancer. In the present study, the nuclear or cytoplasmic HDGF staining level was investigated in 86 patients with primary breast cancer by immunohistochemistry; the relationship between nuclear or cytoplasmic HDGF staining level and clinicopathological parameters was examined by Two-tailed Mann-Whitney U-test or Krustal-Wallis. The prognostic value of nuclear or cytoplasmic HDGF staining level in disease-free survival and overall survival was analyzed by Kaplan-Meier methods and log-rank test. We found that the percentage of cases with strong nuclear HDGF staining level was significantly higher in the cases with high tumor grade, high stage, high proliferation index (Ki-67 index>20%), as well as in those with lymph node invasion and recurrence (p<0.05) compared to those without. No significant correlation was found between cytoplasmic HDGF expression and any clinicopathological variables. In addition, disease-free survival and overall survival were significantly lower in patients with high nuclear HDGF expression (level 2) than in those with low nuclear HDGF expression (level 0 and level 1). Further Cox multivariate analysis showed that high nuclear HDGF expression is an independent factor for indicating poor prognosis in breast cancer patients. No significant difference in disease-free survival rate and overall survival was found between different cytoplasmic HDGF staining levels. All these findings suggest that increased nuclear HDGF expression is involved in tumor progression and might be used as a new prognosticator for breast cancer.