Diagnosis of Breast Cancer

by Michael Jubinville, MPH

Related Media: Breast Biopsy

Your doctor will ask you about your symptoms, and health and family history. The breasts will be check for lumps, thickening, nipple discharge or inversion, and changes in the skin. The underarm will also be checked. Keep in mind that cancer is not the cause of all breast changes. Testing will help find the cause so it can be treated.

You may need:

Blood Tests

Blood tests are used to look for certain proteins or gene problems. Certain proteins (called tumor markers) are higher in people with cancer. Markers can also help find the stage cancer is in and if treatment is working. Blood tests are used to count certain types of blood cells to see if they are in the right range.

Imaging Tests

These tests are used to see structures in the breast and chest. Some tests use contrast material so structures easier to see. Common tests include:

Mammogram

A mammogram is an x-ray of the breast. It can often find tumors that are too small to be felt. How correct the test is depends on tumor size, age, how dense the breast is, and the skill of the doctor looking at the x-ray. Despite its successes, mammograms will miss breast cancer in 15 of 100 women.

Ultrasound

During an ultrasound, sound waves are bounced off tissues and turned into a picture. This test is used to check lumps that were found another way such as by exam or mammogram. They help to see if a mass is solid or liquid-filled. For the most part, solid masses are more of a worry.

Ultrasound may also be used to:

See where the cancer has spread
Find any cancer cells in the breast ducts
Look for cancer that has spread to the lymph nodes under the arm

MRI Scan

An MRI scan of the breast may find certain types of cancer easier than other tests. It is used when the breast is denser or if the doctor thinks cancer may be in both breasts. MRI scans can also be used if results from other tests do not match up.

Diagnosis of Breast Cancer

Other tests may hint there is breast cancer, but a biopsy is the only way to confirm it. During a biopsy, breast tissue is removed and looked at in a lab.

Biopsy types include:

Fine needle aspiration—A thin needle is used to remove fluid and cells from a lump.
Core needle —A larger, hollow needle is used to remove a wider area of tissue.
Vacuum-assisted —A small cut is made in the skin. A hollow device is placed into the tissue to get it out. A small knife inside the device cuts the sample from the breast tissue.
Surgical—During a surgical biopsy, all or part of a lump is removed. There are 2 types. An incisional biopsy removes a small part of a large lump, while an excisional biopsy removes the whole lump (usually a small one).

An MRI scan or ultrasound can be used to guide the needle into the right place.

Staging of Breast Cancer

If breast cancer is found, results from tests taken and new tests will help find the stage of cancer. Staging is a way to find the type of tumor, how far it has spread, and if it is in the lymph nodes. All of this is used find the outlook and the best way to treat the cancer.

Staging Tests

These tests include:

Imaging tests—To see if cancer has moved into other places in the breast, nearby structures, or to other parts of the body. These may be:
- CT scan
- MRI scan
- Bone scan
- PET scan with or without CT scan
Lymph node biopsy—Cancer can drain from the tumor into lymph nodes. From there, it can travel to other places in the body. Lymph nodes under the arm are checked during a breast biopsy, or if they are swollen or felt during the physical exam. The types are:
- Sentinel lymph node biopsy—Sentinel lymph nodes are the first nodes that a tumor will drain into. Contrast material is placed near the tumor. It is watched to see which node it goes to first. Once found, it is tested for cancer. It is not likely the cancer has spread if the node does not have cancer. Lymph nodes with cancer are removed and others are checked until they are cancer-free.
- Axillary node dissection—Removal of a lymph node from the underarm. This is also done if the sentinel lymph nodes have cancer. It can be done as part of a modified radical mastectomy for breast cancer treatment.
Cancer tissue from the biopsy will be closely looked at in a lab. The type of cancer helps with an outlook and treatment plan. The lab will look for certain hormones or proteins that help cancer grow.

Stages of Breast Cancer

Breast cancer is staged from 0-4:

Stage 0—Carcinoma in situ —A very localized group of abnormal cells are still contained in the original tumor site. The cancer stays in the breast and has not spread.
Stage 1A —The tumor is no larger than 2 centimeters (cm) in size and has not spread past the original tumor site in the breast.
Stage 1B —The tumor is not present OR up to 2 cm in size WITH small clusters of cancer cells in the lymph nodes.
Stage 2A
- The tumor is not present OR is up to 2 cm in size WITH cancer found in 1 to 3 lymph nodes in the underarm or in the lymph nodes near the breastbone (in the center of the chest) OR
- The tumor is 2 to 5 cm in size, but has NOT spread to any lymph nodes
Stage 2B
- The tumor is 2 to 5 cm in size WITH small clusters of cancer cells found in the lymph nodes OR
- The tumor is 2 to 5 cm in size WITH cancer found in 1-3 lymph nodes in the underarm or in lymph nodes near the breastbone OR
- The tumor is more than 5 cm in size, but has NOT spread to any lymph nodes
Stage 3A
- The tumor is not present OR is any size WITH cancer in 4 to 9 lymph nodes in the underarm or in lymph nodes near the breastbone OR
- The tumor is more than 5 cm in size WITH small clusters of cancer cells found in the lymph nodes OR
- The tumor is more than 5 cm in size WITH cancer found in 1 to 3 lymph nodes in the underarm or in lymph nodes near the breastbone
Stage 3B
- The tumor is any size and WITH cancer in the the chest wall WITH/WITHOUT swollen or ulcerated skin on the breast AND
- Up to 9 lymph nodes in the underarm OR in lymph nodes near the breastbone
- Note: If cancer has spread to the skin causing swelling or ulcers, it may be inflammatory breast cancer. This type of cancer is stage 3B or higher.
Stage 3C
- The tumor is not present OR is any size WITH/WITHOUT cancer in the chest wall AND/OR swollen or ulcerated skin on the breast WITH spreading to 10 or more lymph nodes in the underarm OR
- To lymph nodes above and below the collarbone OR
- To the lymph nodes in the underarm and lymph nodes in the breastbone
Stage 4 —Cancer has spread beyond the breast and lymph nodes to other parts of the body. The most common sites for breast cancer that has spread are in the bones, lungs, brain, and liver.

Treatment and outcomes depend on many factors such as the location, tumor size, stage, overall health, and age.

References:

Breast cancer. Merck Manual Professional Version website. Available at: https://www.merckmanuals.com/professional/gynecology-and-obstetrics/breast-disorders/breast-cancer.

Breast cancer early detection and diagnosis. American Cancer Society website. Available at: https://www.cancer.org/cancer/breast-cancer/screening-tests-and-early-detection.html.

Breast cancer in women. EBSCO DynaMed website. Available at:
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Palpable breast mass evaluation in women. EBSCO DynaMed website. Available at:
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Sentinel lymph node biopsy for breast cancer. EBSCO DynaMed website. Available at:
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Stages of breast cancer. National Cancer Institute website. Available at: https://www.cancer.gov/types/breast/patient/breast-treatment-pdq#section/_148.

Tumor markers. National Cancer Institute website. Available at: https://www.cancer.gov/about-cancer/diagnosis-staging/diagnosis/tumor-markers-fact-sheet.

Last reviewed December 2020 by EBSCO Medical Review Board Mohei Abouzied, MD, FACP
Last Updated: 3/12/2021

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