Inflammatory Breast Cancer

April 10, 2025

This page was reviewed under our medical and editorial policy by Susan Yost, Ph.D., staff scientist, Department of Medical Oncology & Therapeutics Research, City of Hope^® Cancer Center Duarte

Inflammatory breast cancer (IBC) is a rare type of breast cancer that affects the skin of the breast. Unlike more common types, this cancer blocks the lymph vessels, which causes the breast to appear swollen, red and inflamed.

It grows quickly and may not cause a breast lump like other breast cancers. Because of its unique symptoms, it is important to recognize the signs early and seek medical attention if changes in the breast’s appearance occur.

What Is Inflammatory Breast Cancer?

Inflammatory breast cancer is rare, making up only a very small fraction of all breast cancer cases. It tends to affect younger women, often those under 40, and is more aggressive than other types of breast cancer.

It grows and spreads quickly, often reaching nearby lymph nodes or distant areas of the body by the time it is diagnosed. All inflammatory breast cancer starts as Stage 3 breast cancer. This means it has grown into the skin or nearby tissue.

In about a third of cases, when it is first found, IBC has already spread (metastasized) to other parts of the body. This may make it more challenging to treat.

The redness, swelling or skin changes associated with IBC may be mistaken for other health conditions, such as an infection or an injury.

Additionally, IBC may be harder to detect with standard mammograms. Many women with IBC have dense breast tissue, which may make it harder to spot the cancer on a mammogram. Because of its aggressive nature, IBC may develop and spread quickly, even between regular mammogram screenings.

Is It an Aggressive Form?

Inflammatory breast cancer is considered a very aggressive form of breast cancer. It develops and spreads much more quickly than other types, often progressing in just weeks or months.

By the time it is diagnosed, IBC has usually already spread to nearby lymph nodes or, in more advanced cases, to other parts of the body.

How Common Is Inflammatory Breast Cancer?

Inflammatory breast cancer is quite rare, making up between 1% and 5% of all breast cancer cases, according to the National Cancer Institute. Since it is rare and the symptoms of IBC may resemble more common conditions, some patients are initially treated for an infection (that does not improve with antibiotics) before IBC is diagnosed.

Inflammatory Breast Cancer Symptoms

IBC causes symptoms that usually appear quickly, often within three to six months. Common symptoms may include redness, swelling and pitting of the skin across the breast, and an inverted nipple.

Since IBC progresses quickly, it is important to see a health care provider if any of these symptoms develop.

What Does Inflammatory Breast Cancer Look Like?

One of the first signs of IBC is swelling, along with redness that may cover a large portion of the breast. The skin might look and feel thick or bumpy, resembling the texture of an orange peel (also called peau d'orange).

While a noticeable lump may or may not be present, the breast shape might become distorted, and the skin might feel thick or crusted. Due to swelling, one breast may appear larger or feel heavier than the other, and the affected breast might feel warmer to the touch. Some people may experience tenderness, pain or itching in the breast.

Other common symptoms include changes to the nipple, such as inversion or flattening.

In some cases, lymph nodes under the arm or near the collarbone may also swell.

Pictures of Inflammatory Breast Cancer in Early Stages and Later

Does Inflammatory Breast Cancer Hurt?

Inflammatory breast cancer may cause discomfort. Many people experience tenderness, pain or itching in the affected breast. The breast may also feel heavier or warmer than usual. These symptoms often occur along with swelling and redness.

Inflammatory Breast Cancer Versus Mastitis

IBC and mastitis share similar symptoms, such as breast tenderness, redness, warmth and itching. Mastitis is an infection of the breast, most often seen in pregnant or breastfeeding women. Since mastitis is more common, a doctor may initially suspect an infection and prescribe antibiotics.

While antibiotics may successfully treat mastitis, IBC will not improve with this treatment. If symptoms persist or worsen after seven to 10 days of antibiotics, further testing is needed to check for IBC. It is important to inform the care team if symptoms do not improve, especially if the redness or swelling spreads.

What Causes Inflammatory Breast Cancer?

The exact cause of inflammatory breast cancer remains unknown, but researchers have identified some potential factors. Hormones, genetic changes and environmental factors may play a role.

One known risk factor is having a high body mass index (BMI), an estimate of body fat based on height and weight. A high BMI increases the likelihood of developing IBC. Possible factors still under investigation include viral infections, smoking, younger age at first childbirth and breastfeeding. However, inherited genetic mutations and family history do not seem to be linked to an increased risk for developing IBC. Further research is needed to fully understand what causes this rare form of breast cancer.

How Is Inflammatory Breast Cancer Diagnosed?

Diagnosing IBC may be challenging because it often does not form a lump that is able to be felt or seen on a standard mammogram. If IBC is suspected, doctors may use several imaging tests, such as a mammogram, breast ultrasound or magnetic resonance imaging (breast MRI) scan, to look for abnormalities. In some cases, they may also photograph the breast to document the redness and swelling.

A biopsy is required to confirm the diagnosis. During this procedure, doctors remove a small piece of tissue from the affected area and examine it under a microscope. While other tests may suggest IBC, only a biopsy is able to confirm the presence of cancer.

The care team will also test the biopsy sample for specific proteins, such as hormone receptors and HER2, which may help guide treatment options.

Inflammatory Breast Cancer Treatment

IBC treatment depends on the stage of the cancer at diagnosis. Since they involve the skin, all IBCs start as Stage 3.

For Stage 3 IBC, where the cancer has not spread beyond the breast or nearby lymph nodes, treatment typically starts with chemotherapy. Chemotherapy for breast cancer aims to shrink the tumor before surgery, and if the cancer is HER2-positive (meaning it makes too much of the HER2 protein), breast cancer targeted HER2 therapy is given alongside chemotherapy.

After chemotherapy, surgery is performed to remove the cancer, usually involving a mastectomy (removal of the breast) and lymph node removal. Following breast cancer surgery, radiation therapy is used to destroy any remaining cancer cells. Sometimes, more chemotherapy may be given after surgery but before radiation therapy.

If the cancer is hormone receptor-positive, meaning it binds to hormones (estrogen and progesterone), hormone therapy is also recommended. However, most inflammatory breast cancers are hormone receptor-negative, and hormone therapy will not work on these cancer types.

For Stage 4 IBC, where the cancer has spread to other parts of the body, treatment focuses on therapies that affect the entire body (systemic). These treatments may include chemotherapy, hormone therapy (if the cancer is hormone receptor-positive) and therapies that target HER2 (if the cancer is HER2-positive). Breast cancer immunotherapy, to rev up the body’s own disease-fighting mechanisms, may also be an option for some patients.

In some cases, surgery or radiation therapy may still be an option to control symptoms or improve quality of life. However, treatment is typically focused on controlling the cancer’s spread with medications. Combining these treatments helps manage the disease and may improve outcomes.

Inflammatory Breast Cancer Survival Rate

The five-year survival rate for inflammatory breast cancer depends on how far the cancer has spread at diagnosis. The relative survival rate compares women with IBC to those in the general population.

According to the American Cancer Society, for IBC that is in the regional stage — meaning it has spread to nearby lymph nodes or tissues — the five-year relative survival rate is 52%. If the cancer has spread to distant parts of the body (metastatic or Stage 4), the five-year relative survival rate is 19%.

It is important to note that these numbers are based on women diagnosed between 2012 and 2018. Since then, treatments have improved, and women who are diagnosed today may have a different outlook. Survival rates are estimates and do not consider individual factors like age, overall health or how well the cancer responds to treatment. Therefore, they do not predict how an individual patient’s disease will progress.