The Tumors & Stages of Breast Cancer Explained


The words no woman wants to hear, “You have breast cancer.” The American Cancer Society estimates there will be approximately 297,790 new cases of invasive breast cancer in 2023. Sadly, it’s estimated more than 43,700 women will die from breast cancer in 2023 as well. These numbers have increased in recent years.

A cancer diagnosis can be a scary, stressful and confusing time in a woman’s life. There are so many different words and terms when it comes to describing and characterizing cancer. It’s easy to get lost. Dr. Arshin Sheybani, UnityPoint Health, explains what it all means.

Glossary of Common Breast Cancer Terms

When explaining the different stages of cancer and various parts of the body it affects, a variety of terms are used. The lingo can be confusing and scary when you’re not sure what means what. Below are terms a woman diagnosed with breast cancer may hear:

  • Local. This term is used to describe cancer that’s within the breast.
  • Regional. This term describes the stage of breast cancer when cancer cells are present in the lymph nodes, primarily those around the armpit.
  • Distant. This signifies that cancer is found in other parts of the body.
  • Lymph nodes. The human body has a network of lymph vessels and nodes. Lymph nodes are part of the immune system and collect fluids, waste materials, viruses and bacteria that are found in the body’s tissue.
  • Axillary lymph nodes. This type of lymph node is found in the underarm. They form a chain that goes from the underarm to the collarbone. Knowing if these nodes have cancer cells helps to determine which stage the breast cancer has reached.
  • Invasive. When a doctor uses the term invasive, they mean that cancer has grown into a woman’s normal body tissue and part of the cancer has stayed within the milk lobules.
  • Non-invasive. If cancer has been described as non-invasive, this means abnormal cells have grown inside the milk ducts but haven’t spread beyond the milk ducts.

Cancer Stages

First and foremost, it’s important to understand what a cancer stage means. Cancer stages are categorized based on four characteristics that describe the degree of cancer in the body:

  • The size of the tumor
  • Whether cancer is in the lymph nodes
  • Whether cancer is invasive or non-invasive
  • If cancer has spread beyond the breast

Determining a cancer’s stage is the most crucial aspect of a patient’s prognosis and guides decisions about what is the best treatment option.

Stage 0

Non-invasive breast cancer would be described as Stage 0. In this stage, there is no sign of cancerous cells or non-cancerous abnormal cells breaking out of the breast in which they began or invading nearby tissue.

Stage I

Stage I breast cancer is invasive. This cancer is broken down into subcategories: IA and IB.

Stage IA describes invasive breast cancer in which:

  • The tumor is measures up to 2 centimeters AND
  • The cancer has not spread beyond the breast

Stage IB describes:

  • There is not a tumor in the breast, but small groups of cancerous cells are found in the lymph nodes OR
  • There is a small tumor in the breast and a small group of cancer cells in the lymph nodes

Stage II

Similar to stage I breast cancer, stage II is broken down into two subcategories: IIA and IIB.

Stage IIA is characterized as:

  • No tumor is found in the breast, but cancer is found in 1 to 3 axillary lymph nodes or lymph nodes near the breastbone OR
  • The tumor measures 2 centimeters or smaller and has spread to the axillary lymph nodes OR
  • The tumor is larger than 2 centimeters but not larger than 5 and has not spread to the axillary lymph nodes.

Stage IIB breast cancer is described as:

  • The tumor has grown larger than 2 centimeters but isn’t larger than 5. Small groups of breast cancer cells are found in the lymph nodes OR
  • The tumor is larger than 2 centimeters but not larger than 5, and the cancer has spread to 1 to 3 axillary lymph nodes or lymph nodes near the breastbone OR
  • The tumor has grown larger than 5 centimeters but hasn’t yet spread to axillary lymph nodes.

Stage III

Stage III breast cancer is divided into three subcategories:

Stage IIIA means:

  • No tumor is found within the breast, or the tumor could be any size. Cancer is found in 4 to 9 axillary lymph nodes or near the breastbone OR
  • The tumor has grown to be 5 centimeters or larger, and small groups of breast cancer cells have been found in the lymph nodes OR
  • The tumor has grown to be 5 centimeters or larger, and cancer has spread to 1 to 3 axillary lymph nodes.

Stage IIIB means:

  • The tumor could be any size and has spread to the chest wall or skin of the breast and caused swelling AND
  • Cancer has spread to up to 9 axillary lymph nodes OR
  • May have spread to lymph nodes near the breastbone.

Stage IIIC means:

  • There could be no sign of cancer in the breast, or if there is a tumor, it could be any size and may have spread to the chest wall or skin AND
  • The cancer has spread to at least 10 axillary lymph nodes OR
  • The cancer has spread to the lymph nodes above or below the collarbone OR
  • The cancer has spread to axillary lymph nodes or lymph nodes around the breastbone.

Stage IV

This stage of breast cancer describes cancer that’s invasive and has spread beyond the breast. Cancer has spread to lymph nodes and other organs, such as the lungs, brain, skin or bones. This cancer stage is often described as “advanced.”

Tumor Stages

Tumors also have various stages. Researchers use the TNM system (tumor, node, metastasis) to better understand the cancer staging and to provide details about how a woman’s cancer looks and acts. This system of staging is based on three separate characteristics:

  • Lymph node involvement
  • Tumor size
  • If cancer has metastasized or spread

Breast Cancer Prevention

Unfortunately, there’s no guaranteed way to prevent breast cancer.

“There are many factors that contribute to a woman’s risk for breast cancer that are beyond our control including age, genetics and the mere fact of being female,” Dr. Sheybani says.

However, there are steps women can take to lower their risk. Anne Varner, UnityPoint Health, provides the following as a great starting point to help lower the risk of any type of cancer:

  • Avoid tobacco use. The American Cancer Society estimates smoking accounts for about 30% of all cancer deaths in the United States.
  • Eat a healthy, balanced diet. Opt for fruits, vegetables, lean protein and whole grains.
  • Maintain a healthy weight and be physically active. The Centers for Disease Control and Prevention recommend 150 minutes of moderate-intensity movement per week, and strength training on two or more days a week.
  • Get vaccinated: Certain immunizations can help reduce your cancer risk.
    • HPV vaccine: This vaccine helps prevent cervical and other genital cancers, as well as squamous cell cancers of the head and neck.
    • Hepatitis B vaccine: This vaccine reduces the risk of developing liver cancer and non-Hodgkin lymphoma.
  • Limit sun exposure. Skin cancer is the most common type of cancer and one of the most preventable types of cancer.
  • Receive regular preventative medical care and screenings for various types of cancers based on your gender and age.
  • Limit alcohol intake. If you drink, women should have no more than one drink per day, and men no more than two.
  • Manage stress. Aim for seven to nine hours of sleep each night as well.

UnityPoint Clinic Wants to Help Prevent Breast Cancer

It’s important to be aware of the look and feel of your breast tissue to detect breast cancer and to see your doctor for annual physicals. Talk to your doctor if you notice any changes in your breasts, or if you have a family history of breast cancer. Schedule an appointment with a doctor at a UnityPoint Clinic for your physical and talk about whether a mammogram is recommended for you.