p53/PD-L1 co-expression predicts poor prognosis in diffuse large B-cell lymphoma

Objective: To investigate the clinical characteristics and survival of p53 and PD-L1 co-expression in diffuse large B-cell lymphoma (DLBCL) patients. Methods: Immunohistochemistry (IHC) was used to detect the expression of p53 and PD-L1 in tumor cells of 176 patients with DLBCL. Clinical datawere retrospectively examined along with long-term follow-up. Correlation between the expression of p53 and PD-L1 and the clinicopathological characteristics of the patients was assessed. Impact of Rituximab on prognosis among DLBCL patients with positive expression of p53 and PD-L1 was evaluated. Results: p53 expression, PD-L1 expression, and P53/PD-L1 co-expression were present in 44.9%, 42.0%, and 25.6% of patients with DLBCL, respectively. No significant differences existed in the clinicopathological characteristics between patients with positive and negative p53 expressionand between patients with positive and negative PD-L1 expression. However, more co-expression of p53/PD-L1 was observed in patients with non-GCB subtypes (p = 0.005). Survival analysis indicated that patients exhibiting p53/PD-L1 co-expression had decreased PFS and OS compared to those demonstrating positive expression of either p53 or PD-L1, and in addition, both negative p53/PDL1 expression. Rituximab failed to substantially modify the prognosis of patients. p53/PD-L1 co-expression is an independent indicator of adverse prognosis. Conclusions: Co-expression of p53/PD-L1 in DLBCL patients implies an unfavorable prognostic group, which doesn't derive benefit from Rituximab.