Clinical Significance of B7-H1 and B7-1 Expressions in Pancreatic Carcinoma

Cancer cells develop mechanisms to evade immune cells and achieve progression. Aberrant B7-H1 and B7-1 expressions may help pancreatic carcinoma (PC) cells escape immune attack; these molecules can be considered as prognostic markers for patients with PC who have undergone radical resection. We recruited 81 patients who had undergone radical surgical resection for PC between 1999 and 2007. To investigate the prognostic factors, we evaluated the B7-H1 and B7-1 protein expressions in the tissue specimens of these 81 patients by immunohistochemistry and analyzed the clinical and pathological features of these specimens. B7-H1 was expressed mainly in pancreatic islets, and no B7-1 expression was detected in normal pancreatic tissues. B7-H1 and B7-1 expressions were higher in pancreatic carcinoma tissues than in normal pancreatic tissues (P < 0.05). B7-H1 and B7-1 significantly correlated with the pathological grade and tumor-node-metastasis (TNM) stage, respectively (P < 0.05). Furthermore, B7-1-negative or B7-H1-positive statuses were prognostic indicators of poor disease-specific survival (P < 0.05), but only combined B7-1/B7-H1 expression retained the prognostic potential after adjusting by Cox proportional hazards regression models (P < 0.05). Both B7-H1 and B7-1 are expressed in PC; these molecules are important markers for PC progression. Furthermore, combined B7-1/B7-H1 expression can serve as an independent prognostic marker for PC.