# Treatment patterns and clinical outcomes according to PD-L1 status in >2000 patients with early-stage or metastatic triple-negative breast cancer treated in the real-world setting: VANESSA study results

## TL;DR

This study analyzed treatment patterns and outcomes in over 2000 triple-negative breast cancer patients based on PD-L1 status in real-world settings.

## Contribution

The study provides insights into the real-world impact of PD-L1 status on clinical outcomes in triple-negative breast cancer patients.

## Key findings

- PD-L1-positive early-stage TNBC patients had better invasive disease-free and overall survival.
- Metastatic PD-L1-positive TNBC patients had longer progression-free survival on first-line treatment.
- A high proportion of metastatic TNBC cases were de novo, suggesting possible enrollment bias or geographic variations.

## Abstract

The prognostic effect of PD-L1 status in triple-negative breast cancer (TNBC) is uncertain and little is known about PD-L1-positive prevalence and outcomes in the real-world setting.

The multicentre retrospective observational VANESSA study evaluated the prevalence and impact of PD-L1-positive status in 2054 patients receiving systemic therapy for early-stage or metastatic (e/m)TNBC between 2014 and 2017. PD-L1 expression was assessed locally and centrally on archival samples. Descriptive analyses of demographic and clinicopathological characteristics, treatment patterns and clinical outcomes (extracted from patients’ medical records) according to PD-L1 status were prespecified.

Among 1902 patients with eTNBC, 681 (36%) received neoadjuvant chemotherapy and 1261 (66%) adjuvant chemotherapy. Demographic characteristics were generally similar regardless of PD-L1 status, but lower-risk tumour characteristics were more common in the PD-L1-positive subgroup. Invasive disease-free and overall survival were more favourable in PD-L1-positive eTNBC. In the mTNBC cohort, 120/145 (83%) patients had de novo mTNBC. Median progression-free survival on first-line treatment was 7.6 months (95% CI: 4.1–15.0) in PD-L1-positive mTNBC (n = 30) and 4.9 months (95% CI: 3.6–6.1) in PD-L1-negative mTNBC (n = 83).

In eTNBC and mTNBC, PD-L1-positive status was associated with more favourable long-term outcomes, possibly due to tumour-intrinsic characteristics and/or the host immune response. The high proportion with de novo mTNBC may suggest enrolment bias and/or geographic variations in stage at diagnosis.

•The impact of PD-L1 status on TNBC prognosis and real-world outcomes is uncertain.•The VANESSA retrospective study included 2054 patients with early/metastatic TNBC.•Outcomes appeared more favourable in PD-L1+ than PD-L1– early and metastatic TNBC.

The impact of PD-L1 status on TNBC prognosis and real-world outcomes is uncertain.

The VANESSA retrospective study included 2054 patients with early/metastatic TNBC.

Outcomes appeared more favourable in PD-L1+ than PD-L1– early and metastatic TNBC.