What biomarker tests should I ask for with breast cancer

According to the NCCN Breast Cancer Guidelines (2023), there are three essential biomarker tests that should be performed on all newly diagnosed invasive breast cancers:

1. Hormone Receptor Status:

• Estrogen Receptor (ER)
• Progesterone Receptor (PR)

1. HER2 Status Testing

2. Ki-67 (in some cases)

The American Society of Clinical Oncology (ASCO) Guidelines specifically recommend:

• Initial testing should include both immunohistochemistry (IHC) for ER/PR
• HER2 testing using either IHC or in situ hybridization (ISH) methods
• Retesting may be needed if you have metastatic disease or recurrence

The National Cancer Institute (NCI) adds that additional biomarker testing may be recommended in specific situations:

• Genomic tests like Oncotype DX, MammaPrint, or EndoPredict for early-stage hormone receptor-positive cancers to help guide treatment decisions
• PD-L1 testing for triple-negative breast cancer patients considering immunotherapy

Important notes:

1. These tests should be done before starting treatment as they guide therapy choices
2. Results should be available within 2 weeks of biopsy
3. Always discuss the complete testing plan with your oncologist as individual needs may vary

I recommend asking your healthcare team:

• Have all three standard biomarkers (ER, PR, HER2) been tested?
• Would genomic testing be appropriate in my case?
• Are there any additional biomarker tests specific to my situation?

Remember: This information is meant to help you have informed discussions with your healthcare team, who will determine the most appropriate tests for your specific situation.