B7-H1 expression in malignant pleural mesothelioma is associated with sarcomatoid histology and poor prognosis

J Thorac Oncol. 2014 Jul;9(7):1036-1040. doi: 10.1097/JTO.0000000000000177.


Introduction: B7 homolog 1 (B7-H1; aka programmed cell death 1 ligand 1) is a negative costimulatory molecule that is associated with poor prognosis in many tumor types. Given the poor prognosis and the limited treatments available for mesothelioma, we decided to examine B7-H1 expression and its association with survival in patients with mesothelioma.

Methods: Expression of B7-H1 was determined in 106 patients using a mouse monoclonal antihuman B7-H1 (clone 5H1-A3) antibody with immunohistochemistry. Positive expression was defined as ≥5% positively stained cells. Clinicopathologic features and survival were compared between B7-H1-positive and B7-H1-negative groups.

Results: Malignant mesotheliomas of 42 patients (40%) expressed B7-H1. Patients with B7-H1-postive tumors were less likely to be offered or undergo therapeutic surgery (p = 0.03). All sarcomatoid mesotheliomas except one desmoplastic subtype expressed B7-H1. Survival was significantly decreased for patients whose tumors expressed B7-H1 (5 months median, 2-9.5 months interquartile range) compared with those whose tumors did not (14.5 months, 9.25-19 months; p < 0.0001). In a multivariate model, B7-H1 expression and sarcomatoid mesothelioma remained significantly associated with worse survival (risk ratio 1.71, 95% confidence interval 1.03-2.78 [p = 0.04] and risk ratio 2.18, 1.08-4.23 [p = 0.03], respectively).

Conclusions: B7-H1 is expressed in a substantial proportion of malignant pleural mesotheliomas and is associated with poor survival. Almost all malignant pleural mesotheliomas with sarcomatoid differentiation expressed B7-H1. The expression of B7-H1 may have important therapeutic implications for the management of malignant pleural mesothelioma.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • B7-H1 Antigen / analysis*
  • Female
  • Humans
  • Male
  • Mesothelioma / chemistry*
  • Mesothelioma / pathology*
  • Middle Aged
  • Pleural Neoplasms / chemistry*
  • Pleural Neoplasms / pathology*
  • Prognosis
  • Survival Rate


  • B7-H1 Antigen
  • CD274 protein, human