Breast cancer screening with routine mammograms is essential for the early detection of cancer. If your mammogram or other imaging shows an abnormality, a biopsy will likely be recommended.
1. What is a Breast Biopsy?
A biopsy is a procedure that removes a piece of tissue or fluid (sample) from any suspicious area identified during screening. The sample will be examined in a lab to look for cancer cells. A breast biopsy can be done in several ways, depending on factors such as the size and location of the abnormality, the presence of multiple suspicious areas, your overall health, and your personal preferences.
Types of Breast Biopsies Include:
- Fine Needle Aspiration: Uses a thin, hollow needle to take a small amount of tissue or fluid from your breast.
- Core Needle Biopsy: A larger hollow needle is used to remove a larger sample of tissue or fluid.
- Incisional or Excisional Biopsy: Surgery that removes part of the tumor (incisional) or all the tumor (excisional).
- Lymph Node Biopsy: Removes tissue from the lymph nodes under the arm to check for cancer spread.
Understanding the Results of Your Breast Biopsy
After examination, a pathologist will prepare a detailed report describing the important characteristics of the sample, such as the size, weight, and color of the tissue, how the cells look under a microscope, any tests for proteins and cell growth rate, and a diagnosis or summary of the findings
Understanding Benign Breast Biopsy Results
The majority of breast biopsies do not find cancer. Your results may describe a non-cancerous change in the breast. Some common terms you may see in your report include:
- Sclerosing Adenosis (SA)
- Apocrine Metaplasia
- Cysts
- Galactocele
- Duct Ectasia
- Intraductal papillomas
- Fibrocystic Breast Changes and Fibroadenomas
- Atypical ductal hyperplasia
- Atypical lobular hyperplasia
- Usual ductal hyperplasia
- Pseudoangiomatous stromal hyperplasia
Many benign breast conditions do not need to be treated unless they are causing symptoms, and most do not affect your future breast cancer risk. Talk to your healthcare provider about any concerns you may have about benign breast biopsy results.
Understanding Cancerous Breast Biopsy Results
If cancer cells were found in your breast biopsy sample, your pathology report will provide additional information about the cancer’s characteristics. This will help you and your cancer care team decide on the best treatment plan for you. Here is some of the information you may see in your pathology report and how to interpret it:
Invasive or Noninvasive:
- Noninvasive breast cancers are located in the breast ducts and lobules where they started, referred to as ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). These are considered a precancer or stage 0 breast cancer.
- Invasive breast cancer has spread to nearby tissue or beyond the breast, including cancers from stages I to IV.
Grade of the Cancer:
- Grade 1: Cancer cells look slightly different from normal cells and usually grow slowly.
- Grade 2: Cancer cells look noticeably different from normal cells and grow at a faster rate.
- Grade 3: Cancer cells look very different from normal cells and are growing at a faster rate.
Hormone Receptors: The cancer cells in your breast biopsy sample will be checked for estrogen and progesterone hormone receptors. If your cancer tests positive for either of these hormone receptors, hormone therapy may be an appropriate treatment.
On your pathology report, you may see:
- A percentage describing how many cells test positive for receptors.
- An Allred score, combining the percentage of cells with receptors and how well the receptors show up. This score ranges from 0 to 8, with a higher number indicating more receptors.
- The terms “positive” (receptors present) or “negative” (receptors not present).
HER2: HER2 is a protein that controls breast cell growth. Some cancers produce too much HER2, causing uncontrolled growth. An “equivocal” HER2 status means the result is unclear, and a second test may be needed. If your cancer expresses HER2 on one test but not another, it may be classified as HER2-low.
Stage of the Cancer: Breast cancer is staged based on tumor size, cancer spread, and additional characteristics like grade, hormone receptor status, and HER2 status. The staging system includes:
- T: Tumor size and invasiveness.
- N: Cancer presence in lymph nodes.
- M: Cancer spread to other body parts.
These categories determine your breast cancer’s numerical stage. Learn more about breast cancer staging [here].
Type of Breast Cancer: Your biopsy may identify cancer cells as one of these types:
- Infiltrating Ductal Carcinoma: The most common subtype of invasive breast cancer (70-80%) of all patients.
- Infiltrating Lobular Carcinoma: The second most common type of invasive breast cancer. Lobular carcinoma is more likely to occur in multiple locations at the same time and is often hormone-receptor positive.
- Inflammatory Breast Cancer: Rare, with symptoms of swelling or reddened skin, usually without a lump.
- Phyllodes Tumors: Start in the breast’s connective tissue; most are benign, but some can be malignant.
Learn More About Breast Cancer Screening and Treatment
If you have questions about breast cancer screening, your mammogram report, or your biopsy results, please consult your physician. They can help address any concerns you may have. For more information about breast cancer treatment at Missouri Cancer Associates, please call us at (573) 874-7800 or schedule an appointment online, click here.