How A Diagnosis Is Made And What It Means.

Diagnosing Breast Cancer

Read our blog, A Woman’s Role in Her Breast Cancer Care.

Breast cancer is often first suspected when a lump or change is found in the breast or when an abnormal area is seen on a mammogram.

Most of the time, these findings don’t turn out to be breast cancer. However, the only way to know for sure is to do follow-up tests.

This section describes how breast cancer is diagnosed and the factors that affect prognosis (chances for survival) and guide treatment.

Follow-up tests after an abnormal finding on a screening test

Sometimes, breast cancer can be ruled out with a follow-up mammogram (diagnostic mammogram), breast ultrasound or breast MRI.

Follow-Up After an Abnormal Finding on a Mammogram

Follow-Up After an Abnormal Finding on a Clinical Breast Exam

Diagnostic Mammogram

Breast Ultrasound

Breast MRI



A biopsy removes cells or tissue from a suspicious area in the breast. The cells or tissue are studied under a microscope to see if cancer is present.


Core Needle Biopsy

Fine Needle Aspiration (Fine Needle Biopsy)

Surgical Biopsy

Waiting For Biopsy Results

Assessing Margins After a Surgical Biopsy

Preserving Breast Tissue Samples for Pathology

Questions You May Want to Ask Your Health Care Provider Before a Biopsy

Pathology reports

The breast tissue removed during a biopsy is sent to a pathologist. The pathologist studies the tissue and prepares a report of the findings, including the diagnosis.

What is a Pathology Report

Contents of a Pathology Report

Understanding Your Pathology Report After Neoadjuvant Therapy

Questions You May Want to Ask Your Health Care Provider About Your Diagnosis

Factors that affect prognosis and treatment

Learning about the factors that affect prognosis (chances for survival) can help you understand your diagnosis and your treatment options.

Factors That Affect Prognosis and Treatment

Lymph Node Status

Assessing Lymph Nodes

Tumor Size

Tumor Grade

Types of Tumors (how the cancer cells look under a microscope)

Hormone Receptor Status (estrogen and progesterone status)

HER2 Status

Tumor Profiling Score:

     Oncotype DX®


     PAM50 (Prosigna®)

Breast cancer stages and staging

Breast cancer stage describes the extent of the cancer within your body. It’s the main factor affecting prognosis.

Breast Cancer Stages and Staging

Tumor Size and Staging

Lymph Node Status and Staging

Metastases and Staging

Tests for Metastases in People Newly Diagnosed with Breast Cancer

Molecular subtypes of breast cancer

Researchers are studying how molecular subtypes of breast cancer may be useful in planning treatment and developing new therapies.

Molecular Subtypes of Breast Cancer

Triple Negative Breast Cancer

Special types of invasive breast cancer and carcinoma in situ

Some special types of invasive breast cancer and carcinoma in situ are described in this section.

Inflammatory Breast Cancer

Paget Disease of the Breast

Metaplastic Breast Cancer

Emerging areas in breast cancer diagnosis

New tools are under study for use in breast cancer diagnosis. They may give information about tumors to help guide treatment.

Emerging Areas in Breast Cancer Diagnosis

  • What did my biopsy show?
  • What kind of breast cancer do I have? What are the hormone receptor status and HER2 status of my tumor? What are the results of other tests?
  • Where in the breast did the cancer start?
  • What is the grade of my tumor? Is the breast cancer fast-growing or slow-growing?
  • How many lymph nodes were removed? How many had cancer?
  • What is the stage of my breast cancer? How does this affect my treatment options? How does it affect my chances for survival?
  • Besides the stage of my breast cancer, what other factors affect my treatment options and prognosis?
  • Will tumor profiling tests, such as Oncotype DX®, PAM50 (Prosigna®) or MammaPrint®, be done on the tumor tissue? If so, how will the results affect my treatment? If not, why not?
  • Was the entire tumor removed? Were the margins close or positive? Do I need more surgery?
  • Do I need tests to see if the cancer has spread to other organs (such as the bones, liver, lungs or brain)?
  • Would you give me a copy of the pathology report and other test results?
  • Who will discuss my treatment options with me? When will I meet with them? How much time can I take to decide what type of treatment to have? How long will it be before treatment begins?
  • What can I do to prepare for my next appointment?
  • What do I need to consider before treatment begins if I would like to have a child after being treated for breast cancer?
  • Will my tumor be saved? Where will it be stored? For how long? How can it be accessed in the future?

Learn more about talking with your health care provider.

If you’ve been recently diagnosed with breast cancer or feel too overwhelmed to know where to begin to gather information, Susan G. Komen® has a Questions to Ask Your Doctor When Breast Cancer is Diagnosed resource that might help.

You can download, print and write on the resource at your next doctor’s appointment. Or, you can download, type and save it on your computer, tablet or phone during a telehealth visit using an app such as Adobe. Plenty of space and a notes section are provided to jot down answers to the questions.

There are other Questions to Ask Your Doctor resources on many different breast cancer topics you may wish to download.


Susan G. Komen® Support Resources

  • If you or a loved one needs more information about breast health or breast cancer, contact the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or All calls are answered by a trained specialist or oncology social worker, Monday through Friday from 9:00 a.m. to 10:00 p.m. ET. Se habla español.
  • Komen Patient Navigators can help guide you through the health care system as you go through a breast cancer diagnosis. They can help to remove barriers to high-quality breast care. For example, they can help you with insurance, local resources, communication with health care providers and more. Call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636) or email to learn more about our Patient Navigator program, including eligibility.
  • Komen Facebook groups provide a place where those with a connection to breast cancer can share their experiences and build strong relationships with each other. Visit Facebook and search for “Komen Breast Cancer group” or “Komen Metastatic Breast Cancer group” to request to join one of our closed groups.
  • Our fact sheets, booklets and other education materials offer additional information.

Updated 03/24/22