Cancer Breast Cancer Diagnosis Print Breast Tumor Size and Staging How it, along with other factors, determines your treatment options By Pam Stephan Updated August 12, 2019 Medically reviewed by a board-certified physician In This Article Table of Contents Expand TNM System Putting It All Together Stages Tumor Size and Next Steps View All Back To Top BURGER/Getty Images More in Breast Cancer Diagnosis Symptoms Causes & Risk Factors Treatment More Subtypes Living With Support & Coping Prevention Hormone Receptor Positive Breast Cancer Metastatic Breast Cancer Triple Negative Breast Cancer HER2 Positive Breast Cancer Survivorship Benign Breast Conditions View All The size of a breast tumor can give doctors a sense of the severity of a case of breast cancer, but staging that cancer by considering this information along with lymph node status and metastasis is essential to determining the extent of disease, treatment options, and prognosis. Right now, there is not a simple test that can determine all of this and, moreover, what these factors—in combination—mean for a patient. Rather, doctors use the TNM Classification of Malignant Tumors to conclude how these three characteristics together define a case of breast cancer. You will be told the stage of your breast cancer at some point in your cancer journey, especially after you've had a breast biopsy, lumpectomy, or mastectomy. The TNM System for Breast Cancer Staging TNM is the most widely used staging system for breast cancer. Each letter of the acronym stands for a defining element of the disease. T=Tumor Size To measure the size of your tumor before surgery, doctors rely on imaging studies. Standard breast imaging methods include: Mammogram: Traditional film mammography can be used to image breast tissue. If you are post-menopausal, have fatty breast tissue, or have been pregnant, this may be accurate enough. If you have dense breast tissue, digital mammography is more reliable.Breast ultrasound: Ultrasound can be used to make a measurement of a breast tumor, but it has been found to underestimate tumor size and is considered less accurate than mammography.Breast MRI: While a mammogram may find your lump, an MRI might be needed to measure it if your breast tissue is dense or your biopsy shows that the mass is larger than expected. However, while MRI can create a clear image of your tumor, it tends to overestimate the actual size in three dimensions. After reviewing imaging studies, radiologists can approximate your tumor's size. While this may be straightforward in some cases, it may be more challenging in others. Not all tumors are simple, round shapes. For example, the tumor could be elongated like a baked potato and the image could be at an angle that makes it hard to see all of the dimensions. Some tumors even have irregular edges that make it hard to estimate the total diameter. Size is divided into four classes in the TNM system: T-1 0 to 2 centimeters (cm) T-2 2 to 5 cm T-3 Greater than 5 cm T-4 Tumor of any size that has broken through (ulcerated) the skin or is attached to the chest wall N=Lymph Node Status Since cancer can travel through your body in your lymph system, it is important to have the lymph nodes that are nearest to your tumor tested for cancer and micrometastases. Your surgeon may check your lymph nodes by palpating (feeling) the skin just above the lymph nodes and rating what they notice. N-0 The surgeon cannot feel any swollen nodes. N-1 The surgeon can feel some swelling and thinks the nodes are positive (cancerous). N-2 The lymph nodes feel like they are quite swollen, lumpy, and bunched together. N-3 Swollen lymph nodes are near the collarbone. Alternatively, your lymph nodes may be evaluated via a sentinel node biopsy. M = Metastasis Metastasis, the extent to which the cancer has spread, also affects the stage of cancer. M-0 A sample of the nodes have been surgically removed and tested and are clear of cancer. M-1 Nodes have cancer cells or micrometastases in them. The tumor has shed cells beyond its original location, and the cancer may be in other parts of the body. Putting It All Together All of the TNM information will be combined twice, once by the surgeon and again by the pathologist. Each expert will give an opinion about your case in terms of its TNM stage. To officially determine the breast cancer stage, your team may need to know more about: The hormone receptor statusThe grade of the tumor (speed of growth)Where in your body the cancer has traveled to (if it has metastasized) All of these factors affect your diagnosis and will be heavily considered when you and your doctor look at treatment options. Where Can Breast Cancer Spread? The Stages of Breast Cancer Breast cancer has four stages, and if pre-cancerous conditions are included, a fifth. Your stage depends on the tumor's TNM rating. Stage 0 (Precancer) Stage 0 is used for precancerous, or in situ, carcinomas. In this stage, there's no evidence that abnormal cells have broken out of the area where they originated or are invading neighboring tissues. In Situ Carcinomas Stage 1 Stage 1 means it's invasive cancer (cells are moving into surrounding tissues). There are two subcategories: Stage 1A: The tumor measures up to 2 cm.ANDCancer cells have not spread out of the breast into the lymph nodes. Stage 1B: A small group of cancer cells measuring between 0.2 millimeters (mm) and 2 mm is found in the lymph nodes.A stage 1A tumor may or may not exist. An Overview of Stage 1 Breast Cancer Stage 2 Stage 2 is cancer that has become invasive. This stage also is divided into A and B subcategories. Stage 2A: No tumor is in the breast, but cancer larger than 2 mm is present in lymph nodes, either axillary (under the arm) or near the breast bone.ORThe tumor is smaller than 2 cm and has spread to the lymph nodes.ORThe tumor measures between 2 and 5 cm and hasn't spread to the lymph nodes. Under certain conditions, tumors of this size may still be classified as stage 1. Stage 2B: The tumor measures between 2 and 5 cm and small groups of cells (between 0.2 and 2 mm) exist in the axillary lymph nodes.ORThe tumor measures 2 to 5 cm and there is cancer in up to three axillary lymph nodes.ORThe tumor measures larger than 5 cm but isn't in the axillary lymph nodes. An Overview of Stage 2 Breast Cancer Stage 3 Stage 3 cancers are invasive. This stage is divided into three subcategories. Stage 3A: Any size breast tumor (or no tumor) is present and cancer has been found in between four and nine lymph nodes.ORThe tumor is larger than 5 cm and small groups of cancer cells (0.2 mm to 2 mm) are in the lymph nodes.ORThe tumor is larger than 5 cm and cancer has spread to up to three lymph nodes. Under certain conditions, tumors of this size may be classified as 1B. Stage 3B: A tumor of any size has spread to the chest wall and/or skin and caused swelling or an ulcer.ANDCancer may have spread to up to nine axillary lymph nodes or may have spread to lymph nodes near the breast bone.ORThe case fits the criteria for inflammatory breast cancer (skin on the breast is red and may feel warm or be swollen, and cancer has spread to the lymph nodes and possibly the skin). Under certain circumstances, tumors meeting the first two criteria may be classified as stage 2A. Stage 3C: No tumor or a tumor of any size has spread to the chest wall and/or skin.ANDCancer has spread to 10 or more axillary lymph nodes.ORCancer has spread to lymph nodes above or below the collarbone.ORCancer has spread to lymph nodes near the breastbone. Under certain circumstances, tumors meeting the above criteria may be classified as stage 3A. An Overview of Stage 3 Breast Cancer Stage 4 Stage 4 is also called metastatic breast cancer. Rather than being confined to the breast and nearby lymph nodes, it's traveled to other organs. Common metastases sites include the lungs, skin, bones, liver, brain, or distant lymph nodes. It may also be a recurrence of breast cancer that has spread to other areas. An Overview of Stage 4 Breast Cancer Tumor Size and Next Steps Biopsies and imaging studies give an approximate measurement of your tumor, but you need the actual tumor size in order to make the best treatment decisions. After a lumpectomy or mastectomy, your excised breast tissue will be combined with your biopsy tissue, and a pathologist will examine the true size of the mass. The pathological measurement of your tumor is the gold standard for tumor size. Your post-surgical pathology report will summarize your comprehensive diagnosis of breast cancer. With that in mind, it may seem counterintuitive to rely on the tumor size estimations used in TNM staging. But there is good reason for this: Imaging allows you and your surgeon to make the most conservative choice when it comes to breast surgery. Your surgeon will use the information from previous tests as guidance when removing your tumor. If a lumpectomy will remove your cancer, you may be able to avoid a mastectomy. If neoadjuvant chemo may shrink your tumor before surgery, then you may need less tissue removed in a lumpectomy. However, in some cases, such as widely scattered invasive breast cancer, a mastectomy might be the only surgical option. Having the most information and understanding the implications of your tests helps you make informed, intelligent treatment decisions. A Word From Verywell When you plan a doctor visit and you know that you will be discussing your diagnosis, lab results, or treatment plans, you may want to ask someone to come along with you to take notes. If that's not possible, you may want to record the appointment on your phone or a small tape recorder, if permitted. News of any diagnosis often comes with a lot of information, medical terminology, and emotion. Having something you can refer back to can help if you leave your appointment and details are fuzzy. Was this page helpful? Thanks for your feedback! Get honest information, the latest research, and support for you or a loved one with breast cancer right to your inbox. Email Address Sign Up There was an error. Please try again. Thank you, , for signing up. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Breastcancer.org 2018. Breast Cancer Stages. National Cancer Institute 2015. Cancer Staging. Susan G. Komen 2019. Breast Cancer Stages and Staging. Continue Reading Stage 2 Breast Cancer: What to Expect Stage 1 Breast Cancer: What You Need to Know What Can You Expect in Stage 3 Breast Cancer? What Lung Cancer TNM Staging Means An Overview of Lymph Node-Positive Breast Cancer Understanding Breast Cancer Surgery Options What to Expect During a Sentinel Node Biopsy How Breast Cancer Is Treated When Do Surgical Margins Indicate the Need for More Surgery? How Lymph Node Status Affects a Cancer Treatment Plan What Treatments to Expect For Triple-Negative Breast Cancer Micrometastases in Lymph Nodes and Finding the Right Treatment Breast Cancer: The Most Common Cancer In Women An Overview of Inflammatory Breast Cancer When Lung Cancer Spreads to Lymph Nodes What Tests Are Done to Find Kidney Cancer?