Elevated PD-L1 expression predicts poor survival outcomes in patients with cervical cancer

Cancer Cell Int. 2019 May 23:19:146. doi: 10.1186/s12935-019-0861-7. eCollection 2019.

Abstract

Background: Programmed cell death ligand 1 (PD-L1) expression has been shown to associate with poor prognosis in a variety of solid tumors. However, the prognostic value of PD-L1 expression in cervical cancer is still controversial. Therefore, we carried a meta-analysis to investigate the prognostic and clinicopathological impact of PD-L1 in cervical cancer.

Methods: A comprehensive literature search in was performed in PubMed, Embase, Web of Science, and Cochrane Library. The correlation between PD-L1 expression and overall survival (OS), progression-free survival (PFS), and clinicopathological features was analyzed by hazard ratios (HR), odds ratios (OR) and corresponding 95% confidence intervals (CI).

Results: Seven studies with 783 patients were included in this meta-analysis. The combined HR and 95% CI of OS was 2.52 (1.09-5.83), p = 0.031. The pooled results for PFS were HR = 2.07, 95% CI = 0.52-8.23, p = 0.302. The results of subgroup analysis showed that PD-L1 was a significant prognostic factor of poor OS in Asian patients (HR = 4.77, 95% CI = 3.02-7.54, p < 0.001) and of poor PFS in Asian patients (HR = 4.78, 95% CI = 1.77-12.91, p = 0.002). However, the pooled results suggested that PD-L1 was not significantly correlated with lymph node metastasis, tumor size, FIGO stage, depth of invasion, lymph-vascular invasion, or age.

Conclusions: The results of this meta-analysis suggest that PD-L1 overexpression is related to poor OS in patients with cervical cancer and poor PFS in Asian patients with cervical cancer. This study also suggests that PD-L1 is a promising prognostic indicator for cervical cancer.

Keywords: Cervical cancer; Meta-analysis; PD-L1; Prognosis.