Gene Expression Assay in the Management of Early Breast Cancer

Area of Science:

• Oncology
• Genomics
• Personalized Medicine

Background:

• Adjuvant chemotherapy addition to hormonal therapy for estrogen receptor-positive early breast cancer is debated.
• Not all patients benefit from chemotherapy due to low relapse risk or low sensitivity, leading to unnecessary adverse events and costs.
• Classical clinical and histological features are insufficient for optimal treatment decisions.

Purpose of the Study:

• To review diagnostic gene expression profile tests for early breast cancer.
• To discuss the clinical applications of these tests in refining treatment decisions.
• To highlight how these tests personalize therapy and avoid unnecessary chemotherapy.

Main Methods:

• Review of current literature on gene expression profiling tests.
• Discussion of diagnostic tests including Oncotype DX, MammaPrint, PAM50/Prosigna, EndoPredict, MapQuant Dx, IHC4, and Theros-Breast Cancer Gene Expression Ratio Assay.
• Analysis of the clinical utility and decision-making impact of these genomic assays.

Main Results:

• Gene expression profiling refines treatment decisions beyond traditional markers.
• Tests can identify patients who will not benefit from chemotherapy, avoiding toxicity.
• These assays aid in recommending chemotherapy for patients who will benefit.

Conclusions:

• Gene expression profiling is crucial for personalized treatment of early breast cancer.
• These tests optimize the use of adjuvant chemotherapy, improving patient outcomes.
• Genomic assays reduce overtreatment and healthcare costs by tailoring therapy.