Breast Cancer Quad reflex to FISH for ERBB2 (HER2/neu) Amplification in Breast & Gastric cancer

Breast Cancer Quad Reflex to FISH for ERBB2 (HER2/neu) Amplification in Breast & Gastric Cancer

Overview

The Breast Cancer Quad Reflex to FISH for ERBB2 (HER2/neu) Amplification test is a comprehensive diagnostic panel used to evaluate key biomarkers in breast and gastric cancers. It assesses Estrogen Receptor (ER), Progesterone Receptor (PR), HER2/neu, and Ki-67 by Immunohistochemistry (IHC). If the HER2 IHC result is equivocal (2+), the sample is automatically reflexed to Fluorescence In Situ Hybridization (FISH) to confirm ERBB2 (HER2) gene amplification, ensuring accurate diagnosis and treatment planning.

Why is this Test Performed?

• Determines hormone receptor status (ER & PR).
• Evaluates HER2 protein expression.
• Measures tumor proliferation using Ki-67.
• Confirms HER2 gene amplification using FISH when required.
• Helps select the most effective targeted therapy.
• Supports prognosis and personalized cancer management.

Recommended For

• Newly diagnosed invasive breast cancer patients.
• Gastric or gastroesophageal junction adenocarcinoma patients.
• Patients requiring HER2-targeted therapy assessment.
• Cases with equivocal HER2 IHC (2+) results.
• Oncologists planning personalized treatment strategies.

Sample Required

• Formalin-Fixed Paraffin-Embedded (FFPE) tissue block or unstained tissue sections.

Method

• Immunohistochemistry (IHC)
• Reflex Fluorescence In Situ Hybridization (FISH) for ERBB2 (HER2) amplification when indicated.

Preparation

• No patient preparation is required.
• Tissue specimen should be collected and preserved according to pathology guidelines.

Benefits

• Comprehensive biomarker assessment in a single workflow.
• Reduces delays with automatic HER2 reflex testing.
• Improves diagnostic accuracy.
• Guides eligibility for HER2-targeted therapies.
• Enables personalized treatment decisions.
• Supports evidence-based oncology care.

Interpretation

• ER/PR Positive: May benefit from hormone therapy.
• HER2 Positive: Eligible for HER2-targeted therapies.
• HER2 Equivocal (2+): Reflex FISH determines gene amplification status.
• Ki-67: Indicates tumor growth rate and aggressiveness.

Clinical Significance

Accurate assessment of ER, PR, HER2, and Ki-67 is essential for classifying breast and gastric cancers, predicting prognosis, and selecting the most appropriate targeted therapies. Reflex FISH testing provides definitive confirmation of HER2 status, minimizing false-positive or equivocal interpretations and helping clinicians make informed treatment decisions.