Pre-analytical processing protocol of breast biopsies affects multigene panel results

Area of Science:

• Oncology
• Molecular Diagnostics
• Pathology

Background:

• Multigene panels aid in determining adjuvant chemotherapy for breast cancer.
• A 21-gene multigene panel, based on the Oncotype-DX method, was previously developed.
• Accurate prognostic and predictive indicators are crucial for personalized breast cancer treatment.

Purpose of the Study:

• To evaluate the correlation between a 21-gene multigene panel score and progression-free interval (PFI) in breast cancer patients.
• To investigate the influence of pre-analytical specimen processing on multigene panel results.
• To assess the impact of RNA quality on multigene panel performance.

Main Methods:

• Analysis of 183 breast cancer specimens (Stages I-III) from 2005-2010.
• Correlation analysis between multigene panel scores and PFI.
• Subgroup analysis of samples with specific gene amplification criteria.
• Assessment of RNA quality based on formaldehyde buffering.

Main Results:

• No significant association between multigene panel score and PFI in all patients.
• A significant decrease in PFI observed in patients with high multigene panel scores (above 75th percentile) within a selected subgroup (n=71).
• Non-buffered formaldehyde processing correlated with poorer RNA quality and significantly higher multigene panel scores.

Conclusions:

• Pre-analytical variations in specimen processing can significantly influence multigene panel amplification results.
• These variations may have a substantial impact on clinical management and treatment decisions for breast cancer patients.
• Standardization of pre-analytical procedures is critical for reliable multigene panel testing.