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How Many Stages of Breast Cancer are There?

How Many Stages of Breast Cancer are There?

Even if you’ve never been diagnosed with cancer yourself, you’re likely familiar with different “stages” of cancer. They help explain how widespread or advanced the cancer is, and knowing where you fall is important when trying to understand your diagnosis and what types of treatments are on or off the table. Let’s take a more detailed look at what each stage means and how your doctor determines it.

Most cancers have four stages, but breast cancer actually has five – stage zero through stage four -- and they’re represented with Roman numerals.

Stage 0: Abnormal cells are present, but they haven’t spread to surrounding tissue. This stage includes carcinoma in situ (CIS), which may become cancer.

Stage I: Tumor cells have spread to surrounding breast tissue but are still contained to a small area. Often called “early stage,” this stage is divided into IA and IB based on the size of the tumor and where it’s located.

Stage II: Cancer has grown larger but is still in a limited region. This stage is often called “localized” because some lymph nodes may be involved, usually those around the armpit. It’s also separated into an A and B category.

Stage III: Cancer has spread further into the breast, or the tumor has grown larger. Often called “regional” as more lymph nodes are involved, this stage has three subcategories – A, B and C. In the latter two, cancer may have spread to the skin and lymph nodes near the breastbone or collarbone.

Stage IV: Cancer has spread to other parts of the body, possibly the lungs, liver, bones or brain. It may be called “distant spread,” as well as advanced or metastatic breast cancer.

Typically, your doctor will tell you what stage your cancer is after a physical exam and the initial report from a mammogram or other diagnostic test, like an ultrasound. (there’s a chance the stage may be adjusted after a breast biopsy – which is when a sample of breast tissues is removed – or after you have surgery, if needed.)

A term you might hear when discussing a diagnosis and stages is T-N-M:

  • The “T” stands for tumor size
  • The “N” refers to the number of nearby lymph nodes with cancer
  • The “M” notes whether the cancer has metastasized, or spread beyond the breast
  • Receptor status (ER, PR and Her2Neu), Grade and Oncotyping are also used to determine staging.

If you or a loved one has recently been diagnosed with breast cancer, it’s likely an overwhelming feeling between the medical terms and doctor appointments. BRG has a host of resources to help you as you start this journey, like a patient navigator and support groups. Click here to learn more.

Women 40 and over should talk to their doctor about their risk for breast cancer and when they should schedule a mammogram. A mammogram can often find or detect breast cancer early, when it’s small, and even before a lump can be felt. Early detection leads to a greater range of treatment options, including less-extensive surgery and fewer serious side effects. To schedule a mammogram, visit