Breast Cancer Diagnosis, Biopsy & Tests
When a breast abnormality is found, additional testing helps determine the best treatment plan. At Lowcountry Oncology Associates, we guide you through each step, from the initial biopsy to advanced genomic assays. Our goal is to make complex information clear and to connect you with the testing that will shape a personalized care plan.
Talk to us about testing and we will help you understand your results and next steps.
Biopsy Types
A breast biopsy is the only way to confirm whether a breast change is cancer. The most common type is an image-guided core needle biopsy, where a radiologist uses mammogram, ultrasound, or MRI imaging to guide a hollow needle into the area of concern. This enables the removal and examination of small tissue samples under a microscope.
Other biopsy types include:
- Fine needle aspiration: Uses a very thin needle to remove cells or fluid
- Surgical (excisional or incisional) biopsy: Removes part or all of a suspicious lump when needle biopsy is not possible
Our team reviews biopsy results with you and coordinates the next steps in your care.
Receptor Testing (ER/PR/HER2)
Every confirmed breast cancer tissue sample is tested for key receptors:
- Estrogen receptor (ER)
- Progesterone receptor (PR)
- HER2 (human epidermal growth factor receptor 2)
These results show whether the tumor is fueled by hormones or by HER2 proteins. Knowing if your cancer is ER positive, PR positive, or HER2 positive is essential because it helps determine whether hormone therapy, targeted therapy, or chemotherapy is recommended.
Genomic Assays
In some cases, additional testing is done to understand how active the tumor cells are and whether chemotherapy or other treatments are likely to help after surgery. These genomic assays look at groups of cancer-related genes.
Examples include:
- Oncotype DX: Estimates the benefit of chemotherapy and the risk of recurrence for certain early-stage breast cancers
- Ki 67: Measures how quickly cancer cells are dividing and growing
These tests are not needed for everyone, but they can provide valuable insight when treatment decisions are unclear.
What Tests Mean for Your Plan
Each test builds a clearer picture of your breast cancer:
- Biopsy confirms the diagnosis
- Receptor testing (ER, PR, HER2) guides targeted treatments
- Genomic assays such as Oncotype DX and Ki-67 refine the decision on chemotherapy and long-term management
Our physicians combine all of this information to design a personalized care plan that gives you the most effective treatment with the fewest unnecessary side effects.
Frequently Asked Questions
What is an image-guided core needle biopsy?
This is the most common biopsy for breast cancer. Imaging, such as an ultrasound or mammogram, guides a hollow needle into the suspicious area to remove small tissue samples for testing.
What do ER, PR, and HER2 mean?
These are receptors found on breast cancer cells. If your cancer is ER or PR positive, it may respond well to hormone therapy. If it is HER2 positive, targeted therapy may be recommended.
What is Oncotype DX?
Oncotype DX is a genomic test that looks at a group of cancer genes to predict how likely the cancer is to return and whether chemotherapy will help.
What is Ki-67?
Ki-67 is a marker that shows how fast cancer cells are growing. A high Ki-67 may mean a more aggressive cancer, which can influence treatment decisions.
How do I know which test I need?
Your care team will recommend testing based on your diagnosis and individual risk factors. Talk to us about testing, and we will explain what each result means for your treatment plan.
Take the Next Step
Testing results can feel overwhelming, but you do not need to sort through them on your own. Our team at Lowcountry Oncology Associates will explain your biopsy, receptor testing, and genomic assay results in clear terms and guide you toward the best treatment options.