Analysis of PD-L1 Expression in Breast Cancer: A Systematic Review and Meta-Analysis in Asian Population

This study aimed to investigate the level of PD-L1 protein expression in patients with BCs who were of Asian descent.

Three databases were conducted on this article up to August 10th, 2022. The reference lists of the publications were examined for further studies, and in cases of duplicates, a study with a larger sample size was added. In survival analysis, the hazard ratio (HR) was applied to the circumstances characterized by the frequency of occurrences, and for the clinicopathological characteristic, the best-adjusted odds ratio (OR) with a 95% confidence interval (CI) was employed. The Newcastle-Ottawa Scale (NOS) was utilized to evaluate selection criteria, comparison, and exposure to establish the quality of the technique in the under-consideration studies. The Z test determined the association analysis of OS, DFS, and clinicopathological characteristics with PD-L1 expression.

All eight trials for OS and six for DFS were considered, with 4.111 and 3.071 participants, respectively. Overexpression of PD-L1 was linked to a reduced OS compared to individuals with undetectable expression (HR= 1.58, 95% CI 1.04-2.40; P=0.03). We analyzed clinicopathological features, and it elevated in individuals with histological grade III (OR=2.39, 95% CI 1.26-4.54; P=0.008) and positive node (OR=0.68, 95% CI 0.48-0.97; P<0.05).

Overexpression of PD-L1 was associated with a shorter OS in BCs patients. High PDL1 was higher in persons with nodal positivity and histological grade III.