Prognostic Value of Fas/Fas Ligand Expression on Circulating Tumor Cells (CTCs) and Immune Cells in the Peripheral Blood of Patients with Metastatic Breast Cancer

Area of Science:

• Immunology
• Oncology
• Cell Biology

Background:

• The Fas/Fas ligand (FasL) system regulates apoptosis and is crucial for tumor immune surveillance and metastasis.
• Fas/FasL expression in breast cancer (BC) tissues has prognostic implications.
• Investigating Fas/FasL on circulating tumor cells (CTCs) and peripheral blood mononuclear cells (PBMCs) may offer new prognostic insights in metastatic BC.

Purpose of the Study:

• To assess the expression of Fas and FasL on CTCs and PBMCs in patients with metastatic breast cancer.
• To determine the prognostic significance of Fas/FasL expression on CTCs and PBMCs for progression-free survival (PFS) and overall survival (OS).

Main Methods:

• Analysis of Fas and FasL expression on CTCs and PBMCs from 98 metastatic BC patients undergoing first-line treatment.
• Quantification of Fas+/FasL+, Fas-/FasL+, and Fas-/FasL- CTCs and PBMCs.
• Correlation of Fas/FasL expression patterns with PFS and OS.

Main Results:

• High prevalence of Fas, FasL, and combined Fas+/FasL+ expression was observed on CTCs in CTC-positive patients.
• Fas+/FasL+ CTCs were associated with reduced progression-free survival (PFS).
• Fas+/FasL+ PBMCs correlated with increased overall survival (OS), while Fas-/FasL+ and Fas-/FasL- PBMCs showed shorter OS.

Conclusions:

• Fas/FasL expression on CTCs and PBMCs provides significant prognostic value in metastatic breast cancer.
• The Fas/FasL system plays a role in the peripheral immune response and metastatic progression of BC.
• This study highlights the potential of CTC and PBMC Fas/FasL analysis for predicting patient outcomes.