The diagnosis process
Mammograms help find signs of cancer, but breast cancer can only be diagnosed through a biopsy procedure. You may need more tests to learn as much as possible about your condition.
MSK’s GUIDE TO
Breast Cancer Diagnosis, Types & Stages
Overview
Treatment for breast cancer starts with a correct diagnosis. We’re here to help you take the first steps toward getting the best cancer care.
You may be reading this because you’re thinking about getting screened for breast cancer. Maybe you’re waiting for test results. Or, perhaps you or someone you care about just learned they have breast cancer.
This guide will help you understand how breast cancer is diagnosed and what your diagnosis means. Learning as much as you can may help you feel ready to talk with doctors about your care.
Understanding your diagnosis
Your diagnosis most often will describe where the cancer started, its type, and if it has spread. We use this information to create a care plan just for you.
The diagnosis process
How is breast cancer diagnosed?
Breast cancer screening can help find cancer early when it’s easier to treat. Screening guidelines are based on your risk (chances) of getting breast cancer.
If you’re at average risk, we recommend screening each year with a mammogram starting at age 40. People at higher risk may need different types of scans. They also may need breast imaging exams sooner, and more often.
Your risk can be higher if you have a personal or family history of breast cancer, among other risk factors. A risk factor is anything that raises your chances of getting a health condition.
If you’re at high risk, the MSK RISE breast cancer screening program can help. We have experts in what makes someone at high risk for breast cancer. We’ll make a screening plan to watch for any early signs of breast cancer.
Your doctor may see signs or symptoms of breast cancer during a physical exam or screening. If so, they’ll follow up to learn more.
Doctors use many tests and procedures to spot changes that may be breast cancer.
If you have signs or symptoms of breast cancer, your diagnosis process may look like this:
- Physical exam: Your doctor will do a physical exam of your breasts and lymph nodes, feeling for anything that is not normal. Finding a lump does not always mean you have cancer. Many lumps are benign (not cancer). Your doctor will need to do more tests to know for sure.
- Imaging tests: To get a clearer picture of your breast tissue, your doctor may recommend imaging tests, such as a mammogram, ultrasound, or MRI. They may ask you to have 1 or more of these tests, even if you’ve had one before.
- Biopsy: If breast imaging shows an abnormal (not normal) area, your doctor will arrange a biopsy. This is a procedure to remove a small sample of breast tissue or cells to examine under a microscope. A biopsy is the only way to know for sure if the cells are cancer.
What is a breast biopsy?
A breast biopsy is the only way to know for sure if you have cancer.
During a biopsy, your doctor removes a small sample of tissue from your breast. A pathologist is a doctor who uses a microscope to diagnose disease. They’ll examine your tissue sample under a microscope to see if it has cancer cells.
A biopsy also provides information about cancer cells. This helps doctors choose which treatment is best for you. Not all breast cancers are the same. They have different treatments.
It’s important for your care team to have this information so they make a care plan just for you.
There are a few types of breast biopsies. Your doctor will recommend the best biopsy method for you. They can explain why they chose that type of breast biopsy, if you have questions.
What is a fine needle aspiration (FNA)?
During an FNA, a doctor puts a very thin needle into the area with abnormal (not normal) changes. They use the needle to remove a few cells. An FNA often is the preferred way to take a sample of lymph nodes.
An FNA is fast. Any discomfort lasts only a few seconds. If you’re worried about having pain or discomfort, talk with your doctor.
A pathologist then studies the cells under a microscope to see if they’re benign (normal) or malignant (cancer).
If enough tumor cells were collected during the FNA, we can also test for tumor markers. These breast cancer tumor markers include ER, PR, and HER2. They can help us predict how the cancer will respond to a treatment.
What is a core needle biopsy?
We use a core needle biopsy if we need a tissue sample larger than an FNA sample. We also use it if an FNA does not lead to a clear diagnosis. MSK doctors often choose this type of biopsy to sample breast tissue.
During a core needle biopsy, we first numb the area. We then use a larger, hollow needle to remove a thin piece of tissue.
We test the tissue for breast tumor markers, including ER, PR and HER2.
What is an image-guided biopsy?
Image-guided biopsies use imaging to guide a needle into the breast. A radiologist does this type of biopsy. They can find the exact location of abnormal cells or tissue on the image. Most biopsies are done with imaging guidance because it makes the procedure more accurate and precise.
The needle collects cells or tissue from parts of the breast that may have cancer. These areas can be seen on imaging.
What is a surgical biopsy?
A surgical biopsy is a short procedure that takes place in an operating room. You will get light sedation (medicine to make you sleep). You don’t need to stay in the hospital overnight.
During a surgical biopsy, your surgeon makes a small incision (cut). They remove the whole mass of abnormal breast tissue or take a sample. It depends on the size and location of the mass.
We may recommend a surgical biopsy if:
- Other types of breast biopsies do not let us make a clear diagnosis.
- The area that may have cancer cells is too deep or too shallow for an FNA or a core biopsy.
The MSK Difference
We use a testing tool only offered at MSK called MSK-IMPACT®. This test looks at about 500 genes for genetic changes and other tumor traits. Developed by MSK, it finds genetic changes in the tumor that other tests can miss. We use this test to learn which treatments are best for you.
What is genetic testing to diagnose breast cancer?
Your doctor may suggest genetic counseling and testing.
Genetic testing is a medical test. It looks at your DNA to see if you were born with changes (mutations or variants) in genes. These changes raise your chances of getting breast and sometimes other cancers.
We’ll ask for your written permission to do the test. Before testing, we’ll review your personal and family cancer history to help decide which test is right for you. We’ll explain the test and what the results could mean.
The test involves taking a sample of blood or saliva. You can give a blood sample at an MSK location near you. Or, we’ll mail a saliva kit to your home. The sample is sent to a lab for testing.
When the results come back, often in a few weeks, we’ll go over them with you. If the test shows a gene change that raises your cancer risk, we’ll help you understand what that means. We’ll talk about ways to lower your risk, such as extra screenings or even surgery to prevent cancer.
Innovations at MSK
Our experts always are discovering new information about breast cancer. We’re learning ways to diagnose the exact type and stage of breast cancer. We’re finding out how to find it early when it’s easier to treat. Explore breast cancer news from MSK.
Podcast
A Game-Changing Cancer Drug Gives Stage 4 Breast Cancer Patients New Hope
For nearly half of all breast cancer patients – those with low levels of the HER2 protein – targeted treatment options have always been limited. Palliative chemo has been the standard of care in stage 4 metastatic patients – until now.
Understanding your diagnosis
Learning you have breast cancer can be overwhelming. You’ll hear many medical terms you've never heard before. We’re here to help you understand what they mean and why they matter.
To find out what type of breast cancer you have, we look at a sample of your cells under a microscope. We collect this sample during your breast biopsy or breast cancer surgery.
The information in your diagnosis describes important details about the type of breast cancer you have. Your doctors use that information to create the best plan of care for you.
There are several types of breast cancer. This information describes them and explains how we classify (sort) them into each type.
We classify breast cancer types by features that help predict the best treatment for that type. We look at whether the cancer:
- Is sensitive to 2 hormones, called estrogen and progesterone.
- Has proteins that affect breast cancer growth, such as HER2.
- Has a genetic makeup that affects treatment options.
Your breast cancer diagnosis will describe:
Where the cancer started
Breast cancer can start in the cells of different tissues of the breast. The type of breast cancer can depend on where the cancer started.
Where the cancer started
If the breast cancer is spreading
Some tumors stay in the place where they started. But tumors can spread to other parts of the breast or the body.
If the breast cancer is spreading
The stage describes the tumor’s size, location, and how far it has spread
The stage tells us how advanced the cancer is and guides treatment. There are 5 stages, from 0 to 4 (0 to IV). The lower the number, the less the cancer has spread.
The stage describes the tumor’s size, location, and how far it has spread
The hormone and protein receptor status
If your tumor has certain proteins, it may respond to targeted treatments. These are treatments that stop how well the cancer can grow and spread. This is called the hormone or protein receptor status.
The hormone and protein receptor status
Words you may hear:
This means your tumor uses hormones to grow. These tumors are more likely to respond to hormone therapy treatment. The tumor may use either estrogen or progesterone, or both at the same time.
- ER-positive (ER+) means the tumor uses estrogen to grow.
- PR-positive (PR+) means it uses progesterone to grow.
- HR-positive (HR+) means it uses estrogen, progesterone, or both to grow.
These tumors are both ER-negative (ER-) and PR-negative (PR-).
This means your tumor does not use either of the hormones estrogen or progesterone to grow. These tumors tend to grow faster and do not respond to hormone therapy.
HER2-positive breast cancer is cancer that tests positive for a protein called HER2. This protein helps control the growth of healthy breast cells. Tumors like this respond best to treatment that targets this protein.
Many HER2-negative cancers have low levels of the HER2 protein, so they’re called HER2-low breast cancer. About half of all breast cancers are HER2-low. The tumor may not respond well to treatments that target HER2.
These tumors are ER-negative (ER-), PR-negative (PR-), and HER2-negative (HER2-).
This means the cancer does not use estrogen, progesterone, or HER2 to grow. Triple-negative breast cancer is mainly treated with chemotherapy. Some people may be able to join research studies, also known as clinical trials.
Should I think about getting a second opinion about my diagnosis?
If you learn you have breast cancer, we recommend you get a second opinion right away. This will confirm you’re getting an accurate diagnosis and detailed information about the cancer.
It’s best to get a second opinion before surgery or any other treatment. It can help you avoid treatment you may not need. It can make sure you have the right treatment. Getting a second opinion may take a few days to a week. Sometimes it takes longer.
Second opinions are common. There’s no need to worry you’re hurting your doctor’s feelings. They know second opinions are important when they are not experts in the type of cancer you have.
Get a second opinion at MSK
Call our Care Advisors at 646-497-9064 to learn about becoming an MSK patient. They’re ready to help and available anytime, 7 days a week. You can call any hour of the day.
MSK RECOMMENDS
Bring these questions to your next appointment.
Talk about the details of your diagnosis with your doctor. Learning all you can about the cancer you have will help you feel better prepared to make decisions about your care.
- What type of cancer do I have, and what stage is it?
- Will I need more tests before treatment starts?
- What experience do you have in treating my type of cancer?
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- What support services are available to help me cope with my diagnosis?
- How do I tell my family and people I work with about my diagnosis?
- Is molecular or genetic testing important for choosing the best treatment for me?
- What are my treatment options?
- How will MSK help me recover after treatment?
- Will I get side effects from treatment? How can I manage them?
- Will treatment affect whether I can have children? If I’m planning to have children, are there ways to protect my fertility?
Types of breast cancer
What are the types of breast cancer?
There are many types of breast cancer. We are experienced in treating them all, from the most common to the most rare.
This information describes each type of breast cancer and how we classify (sort) them.
Ductal carcinoma in situ (DCIS)
DCIS is an early form of breast cancer that forms in the milk ducts. It’s the most common type of noninvasive breast cancer.
DCIS is graded (classified) based on what the cells look like under a microscope. The higher the grade, the more it looks different from normal cells.
DCIS sometimes involves the nipple, making it look red and scaly. This is a rare form of cancer called Paget’s disease of the breast (or of the nipple).
DCIS may become invasive ductal carcinoma. For most people with DCIS, surgery is most often the only way to tell for sure if you have invasive cancer.
Invasive ductal carcinoma
Invasive ductal carcinoma starts in the milk ducts and spreads to nearby tissue. It’s the most common type of breast cancer. Nearly 8 out of every 10 cases of breast cancer are invasive ductal carcinoma.
Invasive lobular carcinoma (ILC)
ILC starts in the breast’s lobules (small round sacs that make breast milk). This cancer spreads to nearby tissue.
ILC is the second most common type of invasive breast cancer, after invasive ductal carcinoma. Out of every 100 cases of breast cancer, 10 to 15 are ILC.
People who have ILC may notice a thick or full area that does not feel like the rest of the breast. ILC does not always form a lump.
ILC is also called lobular breast cancer.
Triple-negative breast cancer
Triple-negative breast cancer does not use estrogen, progesterone, or HER2 to grow. It can be harder to treat. It does not respond to drugs that target estrogen, progesterone, or HER2 receptors.
Triple-negative breast cancer mainly is treated with chemotherapy. Some people may be able to join clinical trials (research studies) testing new treatments.
Hormone receptor-positive, estrogen receptor-positive, and progesterone receptor-positive breast cancer
We test breast cancer cells to see if they have receptors for estrogen and progesterone. These hormones help cancer grow.
Breast cancer is:
- Estrogen receptor positive (ER+) if it has estrogen receptors.
- Estrogen receptor negative (ER-) if it has no estrogen receptors.
- Progesterone receptor positive (PR+) if it has progesterone receptors.
- Progesterone receptor negative (PR-) if it has no progesterone receptors.
- Hormone receptor positive (HR+) if it has either estrogen or progesterone receptors.
Hormone therapy cuts the cancer off from the hormones that help it grow.
HER2-positive breast cancer
HER2 is a protein that helps control the growth of healthy breast cells. HER2/neu is a gene that acts like an on/off switch to make HER2.
About 1 out of every 5 cases of breast cancer has either extra copies of the HER2/neu gene, or too much HER2. This is called HER2-positive breast cancer.
HER2-positive breast cancer is treated with targeted therapy. These drugs are designed to block the protein and stop cells from growing out of control.
HER2-negative breast cancer and HER2-low breast cancer
A lot of HER2-negative cancers have low levels of the HER2 protein, so they’re called HER2-low breast cancer. About half of all breast cancers are HER2-low.
In the past, the only treatments for HER2-low breast cancer were the same as for HER2-negative breast cancer. This changed in August 2022, when the U.S. Food and Drug Administration approved the first targeted therapy for HER2-low breast cancer that has spread to other body parts and can’t be removed with surgery.
The approval was based on the results of a clinical trial led by MSK.
Inflammatory breast cancer (IBC)
IBC often causes the breast to become red, swollen, and warm. Your breast skin may look thickened or discolored. It may have tiny dimples, puckers, or ridges that make it look like the skin of an orange.
Symptoms can look like an infection. But they’re caused by the cancer blocking lymphatic vessels in the skin and breast tissue. This starts a buildup of fluid (lymph) that can cause:
- Pain
- Discoloration (change in color)
- Swelling
IBC is a locally advanced breast cancer. It can spread fast and should be treated right away.
Learn about our inflammatory breast cancer team.
Metaplastic carcinoma
Metaplastic carcinoma is a rare type of invasive breast cancer. It has a mix of 2 or more kinds of breast cancer cells (most often carcinoma and sarcoma).
It’s also called metaplastic breast cancer. To treat metaplastic carcinoma, we must first learn more about its genetics and biology. This tells us if the tumor is more like a carcinoma or a sarcoma. They’re treated in different ways.
Breast papilloma
A breast papilloma is a small, wartlike growth in the breast’s milk ducts. It’s also called intraductal papilloma.
This condition is benign (not cancer). It can cause a clear or bloody discharge from the nipple. You also may feel a small lump behind or next to the nipple.
Having 1 papilloma does not raise your breast cancer risk.
Breast sarcoma
Breast sarcoma is a very rare form of breast cancer. It does not start in the lobes or ducts. Instead, a tumor forms in the connective or fibrous tissue around them. Only 1 out of every 100 cases of breast cancers are breast sarcoma.
Male breast cancer
Breast cancer in men is more likely to be cured if it’s found early.
Many people who are assigned male at birth do not know they can get breast cancer. Often, they do not talk with their healthcare provider when they find a mass or lump in their breast. The most common symptom of male breast cancer is a lump that can be felt in the breast.
MSK has more information about symptoms, diagnosis, and treatment of male breast cancer.
The MSK Difference
Only 5 out of every 100 people with breast cancer have a rare type, making it hard to find experts. MSK’s Rare Breast Cancer Program sees about 200 people a year with rare cancer types. Our team can help create the best plan for you.
Breast cancer stages
The cancer stage describes traits such as the tumor’s size, location, and whether it has spread. The stage tells us how advanced the cancer is. The stage guides the choice of treatment.
There are 5 stages of breast cancer, from 0 to 4 (0 to IV). The lower the number, the less the cancer has spread.
Knowing the stage of the cancer helps you and your doctor decide on the best treatment options for you. You may be able to join a research study, also called a clinical trial, for that stage of breast cancer.
The stage of your cancer is based on:
- The size of the tumor.
- If the cancer has spread to nearby lymph nodes.
- If the cancer has spread to other parts of the body.
What are the stages of breast cancer?
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Stage 0
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Stage 1
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Stage 2
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Stage 3
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Stage 4
The MSK Difference
MSK developed a cancer drug that’s giving people with stage 4 breast cancer new hope. The drug, T-DXd, was approved in 2022. T-DXd is now being tested on other cancers and is changing the way doctors treat cancer.
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MSK patients offer helpful tips on becoming a new patient
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