Types and subtypes of breast cancer
- Medical Review: Carla S. Fisher, MD, MBA, FACS
Breast cancer is grouped into different types and subtypes based on factors including:
- Where the cancer started to form
- Whether it has spread beyond its original location
- Cancer cell biomarkers such as hormone or HER2 receptors
Knowing the type and subtype helps you and your care team choose the most effective treatments.
The main types of breast cancer are noninvasive and invasive. These include:
- Ductal carcinoma in situ, or DCIS (noninvasive)
- Invasive ductal carcinoma
- Invasive lobular carcinoma
Metastatic breast cancer is invasive breast cancer that has spread to other parts of the body.
Subtypes of breast cancer include:
- Hormone receptor-positive breast cancer
- HER2-positive, HER2-low, or HER2-ultralow breast cancer
- Triple-negative breast cancer
There are also less common types of breast cancer, such as male breast cancer, inflammatory breast cancer, and Paget disease of the breast.
Below, we’ll explain how type and subtype are determined, what they mean, and ways they can be treated.
How type and subtype are determined
Breast cancers can be grouped into different types and subtypes based on certain characteristics. These include:
- Where the cancer cells first started growing in the breast, such as:
- The lobules: the tiny sac-shaped glands that produce milk
- The ducts: the small tubes that carry milk from the lobules to the nipple
- Whether or not the cancer cells have moved beyond their original location.
- Breast cancer that remains inside the duct is noninvasive, and is called ductal carcinoma in situ (DCIS). Carcinoma means cancer that forms in the inner lining of an organ.
- Cancers that have grown beyond the duct or lobule are called invasive carcinomas.
- Whether the cells have certain features, such as proteins, that might be helping the cancer grow. This helps you and your care team choose effective treatments. For example:
- Hormone receptors are proteins that attach to the hormones estrogen and progesterone. In hormone receptor-positive breast cancer, one or both hormones are helping cancer cells grow.
- HER2 receptors are proteins that, at higher-than-normal levels, can signal breast cancer cells to grow.
- Cancers that test positive for hormone receptors and/or HER2 receptors can be treated with hormonal therapy, targeted therapy, and other treatments.
Invasive ductal carcinoma and invasive lobular carcinoma are the two most common types of breast cancer. Each type can have unique features such as hormone or HER2 receptors. It’s also possible to have a mix of different cell features in one breast tumor.
Carcinoma usually means cancer that develops in the inner lining of an organ. However, abnormal non-cancerous cells that form inside a lobule are called lobular carcinoma in situ (LCIS). Even though carcinoma is part of the name, LCIS is not cancer. Learn more about LCIS.
Your pathology report
Information about the type of breast cancer and its features will be included in a document called a pathology report. A pathologist — a doctor trained to study cells under a microscope to diagnose disease — prepares the report.
You will receive a pathology report any time breast tissue is removed for examination, whether it is a biopsy to check for cancer or surgery to remove cancer. The report will help you and your care team create your treatment plan.
A pathologist will determine the breast cancer type using:
- A piece of the tumor removed during biopsy, or
- The entire cancerous area removed during surgery
The pathologist will also:
- Examine lymph nodes removed during surgery to check for cancer cells
- Perform tests that involve staining the cells, such as an immunohistochemistry test, to determine if there are hormone receptors and/or higher-than-normal levels of HER2 receptors
Visit Understanding your pathology report to learn more.
Noninvasive versus invasive breast cancer
The two most common types of breast cancer are noninvasive (also called in situ carcinoma) and invasive.
- Noninvasive, or in situ, cancer means that the cancer cells are contained within the breast structure where they first started growing, such as the duct.
- Invasive cancer means that the cancer cells have grown through the lining of a duct or lobule and into nearby breast tissue. Invasive cancer can sometimes spread to lymph nodes, and possibly to other parts of the body. However, many invasive cancers do not spread to other parts of the body.
In situ (noninvasive) breast cancer
Ductal carcinoma in situ, also called DCIS, is the only form of in situ breast cancer. In DCIS:
- Cancer cells are found in the lining of the milk ducts, the tubes that carry milk to the nipple.
- The cells have not broken through the duct wall.
- The cancer is sometimes called stage 0.
DCIS is tested for estrogen and progesterone receptors to confirm whether these hormones are helping the DCIS grow. These results help your care team decide if hormonal therapy would help reduce the risk of developing invasive breast cancer in the future.
Learn more about DCIS.
Lobular carcinoma in situ (LCIS)
Despite its name, lobular carcinoma in situ (LCIS) is not cancer. It’s a condition in which there is abnormal cell growth inside the breast’s lobules, the sacs that produce milk.
- LCIS increases the risk of developing breast cancer in the future (in either breast).
- It’s not an immediate threat to your health.
- LCIS is much less common than DCIS.
If you are diagnosed with LCIS, a hormonal therapy such as tamoxifen may be recommended to reduce the risk of cancer in the future.
Read more about LCIS.
Invasive breast cancer
The two most common types of invasive breast cancer are invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC).
- Invasive ductal carcinoma and invasive lobular carcinoma are named for the breast structures where they start growing: the ducts or the lobules.
- The cancer cells have grown through the wall of the duct or lobule and into surrounding breast tissue.
- Invasive ductal carcinoma is much more common than invasive lobular carcinoma.
Invasive breast cancers can be classified further into subtypes. These are based on specific features identified through pathology testing.
Learn more about invasive lobular carcinoma and invasive ductal carcinoma.
Breast cancer subtypes
A breast cancer’s subtype is a classification of breast cancer based on specific features of the cancer, such as hormone or HER2 receptors. Knowing the subtype can help you and your care team choose treatments.
Both ductal carcinoma in situ (DCIS, a noninvasive breast cancer) and invasive breast cancers have subtypes.
Hormone receptor-positive breast cancer
Hormone receptors are proteins inside or on the surface of cells. Hormone receptor-positive breast cancer cells have receptors for hormones that occur naturally in the body: estrogen, progesterone, or both.
This means that:
- Estrogen and/or progesterone fuels the cancer’s growth. The hormones attach to the receptors, signaling cancer cells to divide and multiply.
- The cancer can be treated with hormonal therapies that interfere with hormones’ ability to help the cancer grow.
Learn more about hormone receptor-positive breast cancer.
If the cancer does not have estrogen or progesterone receptors, it is hormone receptor-negative. This means they can’t be treated with hormonal therapy.
Hormone receptor-negative breast cancers:
- Usually grow more quickly than hormone receptor-positive cancers
- Are more common in women who haven’t yet gone through menopause
Depending on other cancer cell features, treatment options for hormone receptor-negative breast cancer may include chemotherapy, radiation therapy, targeted therapy, and/or immunotherapy.
HER2-positive, HER2-low, and HER2-ultralow breast cancer
In HER2-positive breast cancer, the cancer cells have higher-than-normal levels of a protein known as HER2, also called human epidermal growth factor receptor 2. This causes the cancer cells to grow more quickly.
- About 15 to 20% of breast cancers are HER2-positive.
- HER2-positive breast cancer tends to grow and spread more quickly than HER2-negative breast cancer.
- HER2-positive breast cancer is often treated with chemotherapy along with HER2-targeted therapies. These are often given before surgery.
- There are many HER2-targeted therapies available. They include:
HER2-low and HER2-ultralow breast cancers also test positive for HER2 proteins, but at much lower levels. If HER2-low or HER2-ultralow breast cancer cannot be removed with surgery and/or is metastatic, it may be eligible for treatment with trastuzumab deruxtecan.
Learn more about HER2-positive, HER2-low, and HER2-ultralow breast cancers.
Triple-negative breast cancer
Triple-negative breast cancers test negative for estrogen receptors, progesterone receptors, and HER2. These cancers can’t be treated with hormonal therapy or HER2-targeted therapies.
This subtype of breast cancer tends to be more aggressive than hormone receptor-positive and HER2-positive breast cancers.
Triple-negative breast cancers are often treated with chemotherapy and sometimes immunotherapy before surgery to shrink the cancer. Other treatment options can include:
- Radiation therapy
- Targeted therapy, which targets specific features of the cancer cells, such as a genetic mutation or too much of a certain protein
About 10 to 15% of breast cancers are triple-negative. It’s more common in:
- Women under age 40
- Black women
- People who have an inherited BRCA1 mutation that increases cancer risk
Learn more about triple-negative breast cancer.
Molecular subtypes of breast cancer
Molecular subtypes of breast cancer are based on several different features of the breast cancer. They’re mainly used for research purposes, rather than treatment planning. However, you may hear your doctor mention them.
These subtypes are based on features of the cancer cells, such as:
- Hormone receptors
- HER2 levels
- Grade (how abnormal the cells appear)
- How fast the cells are growing
- Ki-67 levels, which measure how quickly cells are dividing
The molecular subtypes include:
- Luminal A
- Luminal B
- Basal-like
- HER2-enriched/HER2-positive
Learn more about the molecular subtypes of breast cancer.
Metastatic breast cancer
Metastatic breast cancer happens when cancer cells move beyond the breast, chest, and armpit lymph nodes into other organs of the body, such as the bones, lungs, liver, or brain. It’s sometimes referred to as stage IV or advanced breast cancer.
Metastatic breast cancer can happen as:
- A first-time diagnosis, also called de novo metastatic breast cancer
- A recurrence of a non-metastatic breast cancer months or years after the initial diagnosis
An estimated 169,000 people in the U.S. were expected to be living with metastatic breast cancer in 2025. This is the most recent available estimate.
Metastatic breast cancer can’t be cured. However, it often can be controlled with ongoing treatment.
Visit Metastatic breast cancer to learn more about treatment options, where to find emotional support, and more.
Special breast cancer types
Most breast cancers are invasive carcinomas or ductal carcinoma in situ (DCIS) affecting women. However, there are other types that occur much less often. Below, you can learn more about these breast cancers.
Male breast cancer
Breast cancer can affect men. Male breast cancer is considered rare, but an estimated 2,670 new cases are expected to be diagnosed in 2026.
Other key facts about male breast cancer:
- Men can be affected at any age, but the average age at diagnosis is 60 to 70 years.
- A family history of breast cancer can increase risk.
- Mutations in genes such as BRCA1, BRCA2, and others can also increase the risk of male breast cancer.
Most breast cancers in men are carcinomas. Carcinomas form in the lining of breast structures, such as ducts and lobules. These types of breast cancer are also common in women. They include:
Because men aren’t routinely screened for breast cancer, tumors in men tend to be larger and more advanced than they are in women. Treatment often includes mastectomy.
Depending on the features of male breast cancer described in the pathology report, other treatment options can include:
Learn more about male breast cancer.
Inflammatory breast cancer (IBC)
Inflammatory breast cancer is a rare type of invasive breast cancer that can be hard to detect because it usually doesn’t form a lump. Instead, symptoms may include:
- Redness
- Swelling
- Thickening
- Warmth
- Dimpling of the skin (like an orange peel)
IBC accounts for about 1 to 5% of breast cancer cases, and it grows and spreads quickly.
While anyone can get inflammatory breast cancer, it’s more common in:
- Women under age 40
- Black women
IBC is also more likely than other breast cancers to be triple-negative or HER2-positive, although it isn’t always.
Visit the inflammatory breast cancer page to learn more.
Paget disease of the breast
Paget disease of the breast, also called Paget’s disease, is a rare form of breast cancer that involves the nipple and areola. The first symptoms usually appear on and around the nipple. They can include:
- Flaking, crusty skin
- Itching, redness, and irritation
- Bloody or yellow discharge from the nipple
- Nipple flattening or turning inward
- A lump under the nipple/areola
Paget disease of the breast is often mistaken for routine skin conditions such as eczema or dermatitis. This can delay diagnosis. While eczema and dermatitis are the most common issues that cause itchiness and redness of the nipple and areola, if symptoms persist for several days after treatment for these diseases, Paget disease of the breast should be considered as a possible diagnosis.
In most cases, people with Paget disease also have another type of breast cancer in the same breast: ductal carcinoma in situ (DCIS) or invasive breast cancer.
The treatment plan depends on what types of breast cancer are found, how much of the nipple and areola are involved, and the results of pathology testing.
To learn more, visit Paget disease of the breast.
Rare types of invasive breast cancer
There are also some rare types of invasive breast carcinoma. They make up only about 1 to 7% of all breast cancers.
Examples include:
- Medullary ductal carcinoma: Instead of forming a distinct lump, this type forms as a spongy area in the breast.
- Mucinous ductal carcinoma: This type is made up of cancer cells surrounded by mucous.
- Papillary ductal carcinoma: This cancer is made up of enlarged ducts and cysts that form finger-like structures.
- Tubular ductal carcinoma: This cancer looks like hundreds of tiny tubes.
Learn more on the invasive ductal carcinoma page.
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Reviewed and updated: May 15, 2026
Reviewed by: Carla S. Fisher, MD, MBA, FACS
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Living Beyond Breast Cancer is a national nonprofit organization that seeks to create a world that understands there is more than one way to have breast cancer. To fulfill its mission of providing trusted information and a community of support to those impacted by the disease, Living Beyond Breast Cancer offers on-demand emotional, practical, and evidence-based content. For over 30 years, the organization has remained committed to creating a culture of acceptance — where sharing the diversity of the lived experience of breast cancer fosters self-advocacy and hope. For more information, learn more about our programs and services.