Breast Cancer

Diagnosing Invasive & Non-Invasive Breast Cancer

Each year in the United States, about 230,000 women find out they have breast cancer. Sometimes, women or their doctors find a breast lump that leads to diagnostic testing. But many times, mammogram screening finds an abnormality or mass before it is big enough to feel. If you have a lump or a suspicious area on a screening mammogram, your doctor may recommend the following tests:

• Diagnostic mammogram 

• MRI 

• Ultrasound 


The results of these tests will guide your next steps. If the results are unclear or suspicious, your doctor may recommend a biopsy. A biopsy removes a small tissue sample to check it for cancer. It is the only way to know for sure if the tissue is cancerous or benign. 
If it is cancer, a surgical biopsy can tell whether the cancer is invasive or non-invasive. Non-invasive breast cancer remains localized to the site where it first started growing. This is stage 0 breast cancer — the earliest form of breast cancer. Invasive breast cancer is a tumor whose cells have grown from its initial site into nearby breast tissue. It can also spread to lymph nodes and other distant areas of the body. Invasive breast cancer includes stages I through IV.

What to expect

There are three main types of breast biopsy procedures:

• Fine needle aspiration biopsy uses a thin needle to take a sample of cells.

• Core needle biopsy uses a larger needle to withdraw a small cylinder — or core — of tissue.

• Surgical biopsy involves an incision through the skin to remove a sample of breast tissue.


Core needle and surgical biopsy are the most common procedures for diagnosing breast cancer. Both can determine whether cancer is present, the type of cancer, and the grade or rate of growth. However, only surgical biopsy can determine the stage of breast cancer. Doctors typically use fine needle biopsy when they suspect a fluid-filled cyst. 
The risks with breast biopsy include bleeding, infection, bruising or swelling of the breast, and changes in breast size or appearance. Talk with your doctor about plans to minimize your risks. Your care team will give you instructions about caring for the biopsy site and when to call or seek medical attention.

What your results mean

The pathology report after a surgical biopsy will describe whether or not the cancer is invasive or non-invasive. This information can help your doctor plan the most effective treatment for you. 

Treatment for non-invasive breast cancer is usually surgery with radiation therapy afterwards. Surgery with radiation therapy is also the main treatment for invasive breast cancer. Depending on the stage of cancer, treatment may also involve chemotherapy. Tumor characteristics from the pathology results will tell your doctor whether hormone therapy or targeted therapies are options and if they are likely to be successful.