Overexpression of B7-H1 (PD-L1) significantly associates with tumor grade and postoperative prognosis in human urothelial cancers.
Cancer Immunol Immunother. 2006 Dec 22; [Epub ahead of print]
* Nakanishi J,
* Wada Y,
* Matsumoto K,
* Azuma M,
* Kikuchi K,
* Ueda S.
Department of Urology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto, 860-8556, Japan, pullpullachan326@bridge.ocn.ne.jp.
PURPOSE:
The programmed death-1 (PD-1)/B7-H1 (also called PD-L1) pathway negatively regulates T cell activation and has been suggested to play an important role in regulating antitumor host immunity. To investigate the clinical significance of B7-H1 expression to the tumor grade and postoperative prognosis of patients with urothelial cancer, we analyzed the relationship between B7-H1 expression and various clinicopathological features and postoperative prognosis.
EXPERIMENTAL DESIGN:
Sixty-five urothelial cancer cases were examined. B7-H1 expression in tumors and the numbers and phenotypes of tumor-infiltrating lymphocytes were evaluated by immunohistochemistry and flow cytometry.
RESULTS:
A substantial expression of B7-H1 was observed in all urothelial cancers investigated. Tumor specimens from patients with higher WHO grade or primary tumor classifications showed significantly higher percentages of tumor-associated B7-H1. Tumor-associated B7-H1 expression was significantly associated with a high frequency of postoperative recurrence and poor survival rate. Furthermore, multivariate analysis indicated that tumor-associated B7-H1 was more significant prognostic factor than WHO grade.
CONCLUSIONS:
Our results demonstrate that the aberrant expression of B7-H1 in urothelial cancer is associated with aggressive tumors, suggesting a regulatory role of tumor-associated B7-H1 in antitumor immunity. Therefore, the manipulation of tumor-associated B7-H1 may become a beneficial target for immunotherapy in human urothelial cancer. |
