Overexpression of B7H5/CD28H is associated with worse survival in human gastric cancer

Gastric cancer (GC) is a common malignancy with low 5‐year overall survival (OS). Recently, immune therapy has been used to treat cancer. B7H5 and CD28H are novel immune checkpoint molecules. However, the prognostic value of B7H5/CD28H expression in patients with GC remains unclear. In this study, seventy‐one patients diagnosed with GC were included in this study. Patients' GC tissues and matched adjacent tissue constructed a tissue microarray. The expression levels of B7H5 and CD28H were examined using immunohistochemistry. Correlations between the expression of B7H5 and CD28H and the clinical data were evaluated. We found that the expression of B7H5 and CD28H (both P = .001) were higher in GC tumour tissues than in adjacent noncancerous tissues. B7H5/CD28H expression acted as an independent predictive factor in the OS of patients with GC. High expression of B7H5 and CD28H predicted poor outcome. Patients in the B7H5+CD28H+ group had a lower 5‐year OS compared with patients in the B7H5−CD28− group (4.5% vs 55.6%, P = .001). A significant difference was found in the 5‐year OS between patients in the B7H5+CD28H− and B7H5+CD28H+ groups (33.5% vs 4.5%, P = .006). However, there was no correlation between B7H5 and CD28H expression (P = .844). Therefore, B7H5 and CD28H expression are up‐regulated in GC and are independent prognostic factors for overall survival in patients with GC. Although there was no correlation between B7H5 and CD28H expression, high expression of B7H5 and CD28H predicts poor prognosis, especially when both are highly expressed.