Inflammatory Breast Cancer

Inflammatory breast cancer (IBC) is a rare and aggressive type of invasive breast cancer in which cancer cells block lymph vessels in the skin. This causes the breast to look inflamed.

What is inflammatory breast cancer?

IBC causes breast swelling and redness from cancer cells blocking lymph vessels in the skin, making the breast look inflamed.

Inflammatory breast cancer is fairly rare, accounting for 1% to 5% of all breast cancers. Most often, it is a type of invasive ductal carcinoma (IDC).

IBC differs from more common types of breast cancer in many ways:

Diagnosis

IBC doesn't usually appear the same way as most breast cancers do. It often doesn’t cause a breast lump, and it might not show up on a mammogram. This can make it harder to diagnose.
IBC is always at least locally advanced when first diagnosed, because the breast cancer cells have grown into the skin. This means it is at least stage III.

Who gets it

IBC tends to occur at a younger age than most other breast cancers, with the average age at diagnosis being 59.
Black women are more likely to develop IBC than White women.

Growth and spread

IBC tends to grow more quickly than more common types of breast cancer.
Compared to other breast cancers, IBC is more likely to have spread to nearby lymph nodes and to have metastasized to distant parts of the body when it is diagnosed.

Signs and symptoms of inflammatory breast cancer

Most signs and symptoms of IBC develop fairly quickly, over the course of a few weeks to months. They can include:

Swelling (edema) of the skin of the breast
Redness involving at least a third of the breast
Pitting or thickening of the skin of the breast, which may cause it to look and feel like an orange peel
A retracted or inverted nipple
One breast looking larger than the other because of swelling
One breast feeling warmer and heavier than the other
A breast that may be tender, painful, or itchy
Swelling of the lymph nodes under the arms or near the collarbone

Having any of these symptoms does not mean that you have IBC, as they can also be caused by other things, but you should see a doctor to have them checked.

For example, tenderness, redness, warmth, and itching are also common symptoms of a breast infection or inflammation, such as mastitis if you’re pregnant or breastfeeding.

Because these problems are much more common than IBC, your doctor might suspect infection at first and treat you with antibiotics. Be sure to let your doctor know if the symptoms don’t get better within about a week, or if they get worse or the affected area gets larger. If so, more tests might be needed to look for cancer.

How is inflammatory breast cancer diagnosed?

Because it involves the skin, IBC is usually diagnosed after a person goes to the doctor because of symptoms. Less often, it’s first seen on a screening mammogram.

Imaging tests

If IBC is suspected, one or more of the following imaging tests may be done:

Often, a photo of the breast is taken as well to record the amount of redness and swelling before starting treatment.

Biopsy

If breast cancer is suspected, a breast biopsy will be done, in which small pieces of breast tissue are removed and looked at in the lab for cancer cells. For suspected IBC, this often includes a punch biopsy of the breast skin that is abnormal.

The actual diagnosis of IBC is made based on a combination of findings:

A rapid onset of breast redness and swelling covering at least a third of the breast
Invasive breast cancer in the biopsy

Tests on biopsy samples

If IBC is found, the cancer cells in the biopsy will be looked at in the lab to determine their grade, which is a measure of how quickly they are likely to grow and spread.

The cells will also be tested to help decide which treatments will be helpful. Tests might be done for:

Hormone receptors, to see whether treatment with hormone therapy drugs might be helpful.
HER2 protein or gene copies, to see whether treatment with certain drugs that target HER2 might be helpful.
Other gene changes (mutations) or proteins, to see whether specific drugs might be helpful.

Stages of inflammatory breast cancer

The stages of invasive breast cancer in general range from I to IV, with stage IV being the most advanced.

All inflammatory breast cancers start as stage III, since they involve the skin. If the cancer has spread outside the breast to distant parts of the body, it is stage IV.

If IBC has been diagnosed, imaging tests such as CT scans, MRI, bone scans, or PET scans will be done to see whether it has spread to other parts of the body.

Treating inflammatory breast cancer

How inflammatory breast cancer is treated depends on its stage and other factors.

Stage III IBC

IBC that has not spread to distant parts of the body is stage III.

Treatment usually starts with chemotherapy, possibly along with immunotherapy or a targeted drug, to try to shrink the tumor.

If the tumor shrinks enough, this is followed by surgery (mastectomy plus removal of the underarm lymph nodes) to remove the cancer. Because IBC affects so much of the breast and skin, breast-conserving surgery (partial mastectomy or lumpectomy) and skin-sparing mastectomy are not good options.

After surgery, radiation therapy and often other treatments like more chemotherapy, hormone therapy, and targeted drugs are given.

Stage IV IBC

IBC that has spread to other parts of the body is stage IV.

It is typically treated with some combination of:

Chemotherapy
Hormone therapy
Targeted drugs
Immunotherapy

Which treatments are used depends on the characteristics of the cancer cells.

Survival rates for inflammatory breast cancer

Survival rates are a way to measure how many people survive a certain type of cancer over time. They cannot tell you exactly what will happen with any one person, but they might help give you a better understanding of how likely it is that treatment will be successful.

What is a 5-year relative survival rate?

A relative survival rate compares people with the same type and stage of breast cancer to people in the overall population.

For example, if the 5-year relative survival rate for a specific stage of breast cancer is 70%, it means that people who have that cancer are, on average, about 70% as likely as people who don’t have that cancer to live for at least 5 years after being diagnosed.

Where do these numbers come from?

The American Cancer Society relies on information from the Surveillance, Epidemiology, and End Results (SEER) database, maintained by the National Cancer Institute (NCI), to provide survival statistics for different types of cancer.

The SEER database tracks 5-year relative survival rates for breast cancer in the United States, based on how far the cancer has spread. The SEER database, however, does not group cancers by AJCC TNM stages (stage I, stage II, stage III, etc.). Instead, it groups cancers into localized, regional, and distant stages.

Localized: There is no sign that the cancer has spread outside the breast.
Regional: The cancer has spread outside the breast to nearby structures or lymph nodes.
Distant: The cancer has spread to distant parts of the body such as the lungs, liver, or bones.

5-year relative survival rates for inflammatory breast cancer

Inflammatory breast cancer tends to grow quickly, is more likely to have spread at the time it’s found, and is more likely to come back after treatment than most other types of breast cancer. Because of this, the survival rates for IBC are generally not as high as they are for other types of breast cancer.

These numbers are based on women diagnosed with IBC between 2015 and 2021.

There is no localized SEER stage for IBC because it has already reached the skin when first diagnosed.

SEER Stage	5-year Relative Survival Rate
Regional	53%
Distant	22%
All SEER Stages	40%

Understanding the numbers

Women now being diagnosed with inflammatory breast cancer probably have a better outlook than these numbers show. Treatments have improved over time, and these numbers are based on women who were diagnosed and treated at least 5 years earlier.

These numbers apply only to the stage of the cancer when it is first diagnosed. They do not apply later on if the cancer grows, spreads, or comes back after treatment.

These numbers don’t take everything into account. Survival rates are grouped based on how far the cancer has spread, but your age and overall health, how well the cancer responds to treatment, and other factors can also affect your outlook.

Keep in mind that survival rates are estimates, and they can’t predict what will happen in any person’s case. These statistics can be confusing and might lead you to have more questions. Ask your doctor how these numbers might apply to you.