Syndecan-1 expression--a novel prognostic marker in pancreatic cancer

OBJECTIVE: Syndecan-1 is a transmembrane receptor that participates in cell-cell and cell-matrix interactions, cell proliferation and cell migration. Expression of syndecan-1 is downregulated in many cancers, but in pancreatic ductal adenocarcinoma it is upregulated. Method: We studied the immunohistochemical expression of syndecan-1 in 144 pancreatic adenocarcinomas and evaluated the prognostic value of syndecan-1 expression. Formalin-fixed, paraffin-embedded specimens were stained with mouse monoclonal antibody B-B4 against human syndecan-1. The epithelial and stromal staining was separately evaluated and compared with patient survival, clinical stage and histological grade. RESULT: Epithelial immunoreactivity was observed in most of the pancreatic carcinoma samples: in 70 (49%) of the samples the epithelial staining was weak, in 48 (33%) moderate, in 18 (12%) strong and in only 8 (6%) of the samples the epithelial staining was negative. Stromal staining was weak in 24 (17%), moderate in 31 (22%), strong in 11 (8%) and negative in 78 (54%) of the pancreatic carcinoma samples. Lack of stromal expression predicted a better prognosis (p = 0.002; HR 1.7) and it was independent of stage (p = 0.01; HR = 1.5) and grade (p = 0.0004; HR 2.1) in multivariate analysis. Epithelial expression predicted better prognosis for patients that underwent surgery for cure (n = 94, p = 0.03). CONCLUSION: Stromal syndecan-1 expression is an independent prognostic marker in pancreatic cancer, whereas epithelial syndecan-1 expression predicts better prognosis only in resectable disease.