HER family receptor expression and prognosis in pancreatic cancer.

Abstract

HER family receptors play a key role in tumor progression in several malignancies, such as colorectal, lung or breast cancer. The aims of this study were to investigate expression of HER-1, HER-2 and HER-3 in pancreatic cancer (PC) samples and evaluate the association between HER-family receptor expression and patients' clinical outcomes. Tissue samples from 91 PC patients were subjected to immunohistochemical staining to assess the expression of HER-1, HER-2 and HER-3. Semiquantitative scores of zero (no staining or staining in less than 10% of cancer cells), 1+, 2+ or 3+ were assigned to each sample based on the intensity of staining for HER receptors. Scores of 2+ or 3+ were defined as positive staining. HER-1 overexpression was observed in 41 out of 91 samples (45.1%), while HER-2 was not overexpressed in any of the analyzed samples. HER-3 was overexpressed in 37 samples (40.7%) and was found to be associated with advanced TNM stage. In particular, HER-3 was overexpressed in 12 out of 16 stage IV patients (75%) compared with only 33.3% of stage I-III patients (p = 0.02). Among 79 patients with available survival data, the 6 patients with strong HER-3 expression (score 3+) had a shorter survival compared with remaining patients (median overall survival 6.9 months vs. 12.3 months, respectively). HER-1 and HER-3 were found to be expressed in a significant proportion of PC patients. Strong HER-3 expression represents an indicator of poor prognosis in PC patients, being associated with advanced stage and shorter survival.