# PD-L1 and BAP1 as Prognostic Biomarkers in Malignant Pleural Mesothelioma

## TL;DR

This study examines PD-L1 and BAP1 as potential biomarkers for predicting survival in patients with malignant pleural mesothelioma.

## Contribution

The study evaluates the prognostic significance of PD-L1 and BAP1 expression in a cohort of MPM patients.

## Key findings

- PD-L1 expression ≥ 1% was found in 39.6% of patients, and BAP1 loss was found in 81.1%.
- Patients with PD-L1 ≥ 1% and BAP1 positivity had significantly shorter progression-free survival (1 vs. 7 months).
- BAP1 loss was associated with longer overall survival (12 vs. 4 months).

## Abstract

Malignant pleural mesothelioma (MPM) is a very aggressive tumor. The prognostic value of PD-L1 and BAP1 expression has been investigated in many studies. A retrospective study was conducted that analyzed PD-L1 and BAP1 expression as prognostic biomarkers in patients with MPM. The study included 53 patients with MPM. PD-L1 expression ≥ 1% was found in 39.6%, and BAP1 loss was found in 81.1% of patients. The median overall survival (mOS) was 11 months. Subtype of MPM (p = 0.045), early tumor stage (p = 0.049), therapy (p = 0.002), and good PS (0–1) (p = 0.012) were associated with better survival. Expression of PD-L1 and BAP1 did not show statistical significance regarding OS, but OS was numerically shorter in patients with PD-L1 ≥ 10% (5 vs. 12 months) and longer in patients with BAP1 loss (12 vs. 4 months). In patients with PD-L1 ≥ 1% and BAP1 loss, the median progression-free survival (mPFS) was numerically longer (10 vs. 7 months) but in patients with PD-L1 ≥ 1% and BAP1 positivity, PFS was statistically significantly shorter (1 vs. 7 months, p = 0.048). Our results did not show that PD-L1 and BAP1 are prognostic biomarkers for MPM, but positive PD-L1 expression and BAP1 loss were associated with worse survival in patients with MPM.