What Are the Stages and Grades of Breast Cancer?
Breast cancer stages tell you how far your cancer has spread in your body. The grade checks how similar your cancer is to normal cells.
Zero and the Roman numerals I, II, III, or IV stand for how far your cancer has spread. But many people simply refer to the stages using numbers 1, 2, 3, and 4.
Many doctors also use the T (tumor size), N (lymph nodes), and M (metastasis) staging system. This system stages breast cancers such as:
- Invasive (infiltrating) ductal carcinoma (IDC), which makes up about 70-80 out of every 100 breast cancer cases
- Invasive (infiltrating) lobular carcinoma (LCIS), which makes up almost 8 in 100 breast cancer cases
- Mixed ductal or lobular carcinoma, which accounts for 7 in 100 invasive breast cancer cases
The strange code strings together letters and numbers to pinpoint exactly what’s going on with your cancer. The long letter and number code helps your doctor plan the best treatment for you.
Knowing your breast cancer stage and grade “can help you mentally and emotionally prepare for what’s ahead,” says Nicketti Handy, MD, breast surgical oncologist of Disney Family Cancer Center at Providence Saint Joseph Medical Center in Burbank, CA.
“You can be empowered to have discussions with your care team regarding treatment planning,” says Handy. “You can ask meaningful questions and discuss topics that are important to you regarding work-life balance, fertility, and body image concerns.”
Breast Cancer Stages
Your breast cancer stage depends on your breast cancer type. Staging also helps your doctor know how much cancer you have in your body.
There are a few ways to stage your breast cancer:
Number staging system. Stage 0 (carcinoma in situ) is the earliest stage, followed by 1 to 4. The lower numbers mean the cancer has not spread as far. Sometimes, doctors get more specific and add A, B, C, or D. A is less advanced.
TNM system.Doctors most often use the TMN system. The TNM system can improve your treatment plan. It combines clues such as:
- Imaging tests like X-rays and bone scans
- Blood tests
- DNA tests
- Biopsies
- Physical exam
Grade and status.The grade looks at how much your breast cancer cells look like your healthy ones. It also tells your doctor how fast your cancer cells are spreading and growing.
Breast cancer hormone receptor status shows if your cancer cells have these receptors. And HER2 status checks to see if your cancer cells make certain proteins.
Stage 0breast cancer
About 20 in 100 breast cancers are ductal carcinoma in situ (DCIS), meaning “in the original place.” Stage 0 DCIS is the earliest stage with abnormal cells in your breast ducts. Ducts are tiny tubes carrying milk to your nipples.
Stage 1 breast cancer
At stage I, your breast cancer is called invasive because it’s in healthy tissue. But the cancer cells are close by, mainly around your breast and lymph nodes. This type of cancer is very treatable and usually affects a small area.
Stage 1A. Your tumor is about the size of a shelled peanut, in the fatty breast tissue, but not in your lymph nodes.
Stage 1B. You’ll have pinprick- to rice-sized clumps of cancer cells in nearby lymph nodes.
Sometimes, stage 1B only shows up in your lymph nodes without a tumor.
Stage 2 breast cancer
Although larger, stage 2 is still close by. The cancer is usually in your breast or nearby lymph nodes.
Stage 2A. You may have cancer in nearby lymph nodes with a peanut- to lime-sized tumor.
Stage 2B. Your tumor is bigger than a lime or walnut- to lime-sized, with cancer in three or fewer nearby lymph nodes.
Stage 3 breast cancer
Stage 3 .Cancer is in nearby lymph nodes but has not spread to distant organs.
Stage 3A. Your tumor can be any size, with cancer in fewer than nine nearby lymph nodes. Or you can have a lime-sized tumor with cancer in a few lymph nodes under your arm or breastbone.
Stage 3B. The tumor spreads to your chest wall or in the skin of your breast, with cancer in up to nine nearby lymph nodes.
Stage IIIC. Your tumor has spread to your chest wall or possibly your breast’s skin. Your cancer is in 10 or more nearby lymph nodes or the lymph nodes near your breastbone or collarbone.
Metastatic breast cancer
Metastatic (stage 4) breast cancer spreads to other organs such as your bones, lungs, liver, or brain. Your tumor is far away from the breast and the nearby lymph nodes.
About 3 out of every 10 early-stage breast cancer cases become metastatic. It can happen months or years after treatment.
“Knowing the stage helps guide treatment planning,” says Amy Bremner, MD, a breast oncology surgeon and medical director for Breast Surgical Oncology at MemorialCare Medical Group, Saddleback Medical Center in Laguna Hills, CA.
“For example, stage 1 might only require surgery and radiation,” says Bremner. “[But] stage 4 is often treated with systemic therapies like hormone therapy, targeted agents, or immunotherapy.”
Breast Cancer Grades and Status
Your doctor removes cancer cells from your breast and lymph nodes to check how similar the cells look to your normal ones. “This refers to how aggressive the cancer cells look under the microscope,” says Bremner.
Breast cancer grading
Testing the grade helps your doctor figure out what treatments work best for you.
Grade 1. Well-defined (differentiated) cancer cells look a lot like healthy cells and grow slowly.
Grade 2. Moderately defined cancer cells look slightly different and grow a little faster.
Grade 3. Poorly defined cells look very different from normal cells and grow quickly to spread.
Your doctor will also check for any areas of dead or dying cancer cells. Tumor necrosis means your tumor is growing quickly.
Breast cancer status
Testing cancer cell receptor status helps predict your best cancer treatment.
Estrogen receptor (ER). Positive ER cancer cells may grow faster with estrogen (a reproductive hormone).
Progesterone receptor (PR). With PR positive cancer cells, progesterone (a reproductive hormone) may help the tumor grow faster.
Hormone receptor positive (HR+). Your cancer has ER, PR, or both.
Hormone receptor negative (HR-). Your cancer cells don’t react to reproductive hormones.
Human epidermal growth factor receptor 2 (HER2). HER2-positive (HER2+) cancer makes extra HER2 protein. It helps breast cancer cells grow quickly.
PD-L1 protein. Certain breast cancer types, such as triple-negative breast cancer, can make the PD-L1 protein. The test helps your doctor know if certain immunotherapy treatments will work.
TNM System for Breast Cancer
Your doctor will do a breast exam and review your medical and family history. They’ll order a mammogram on both breasts (bilateral) and possibly a breast ultrasound.
Your doctor will perform a procedure to remove your tumor. The laboratory will look at your cancer cells. Your doctor will then review imaging, lab tests, and other tests to stage your breast cancer.
“T” stands for tumor size
Your doctor looks at the size of your main breast tumor. They’ll see if you have cancer in your skin or chest wall, too.
The letters or numbers help you know the size or area of your tumor:
Tx — requires more testing
T0 — no breast tumor seen
Tis — carcinoma in situ (DCIS) or Paget’s breast disease
T1a, T1b, and T1c — tumors between the size of a short grain of rice and an almond (0.1 to 2 cm)
T2 — tumors larger than an almond but smaller than a lime (2-5 cm)
T3 — tumors larger than a lime (5 cm)
T4a — cancer spreads into your chest wall
T4b — cancer in your breast’s skin with possible breast swelling
T4c — cancer is in your chest wall and skin
T4d — a rare inflammatory breast cancer
“N” stands for lymph nodes
Lymph nodes are part of your immune system. The bean-shaped organs act like small filters in your body, especially near your breasts.
A special test using antibodies to identify cancer cells (immunohistochemistry).
The reverse transcription-polymerase chain reaction (RT-PCR) test looks for cancer cell gene changes.
The numbers and letters tell you how far the cancer has spread in your lymph nodes:
NX — needs more testing to stage
N0 — cancer not in your lymph nodes
N0 (i+) — about 200 or fewer cancer cells, roughly 0.2 millimeters thick (about the size of two sheets of paper), found in your lymph nodes through immunohistochemistry testing
N0 (mol+) — traces of cancer cells found using DNA testing (RT-PCR)
N1 — cancer cells found in one to three underarm lymph nodes or near your breastbone
N1mi — cancer cells in your lymph nodes under your arm, about 0.2 millimeters thick (about the size of two sheets of paper)
N1a — cancer in one to three lymph nodes under your arm, with cancer in at least one area 2 millimeters or larger (about the size of a crayon tip)
N1b — cancer has spread to normal-sized lymph nodes near your breastbone
N1c — includes N1a and N1b
N2a — cancer has spread to four to nine lymph nodes in your underarm
N2b — cancer found in the lymph nodes of your breastbone, but not your armpit
N3a — tumors are at least the size of a crayon’s tip and are present in 10 or more lymph nodes in your armpit or under your collarbone
N3b — cancer has spread to the lymph nodes in your underarm and near your breastbone
N3c — cancer cells found in your lymph nodes above your collarbone
“M” stands for metastasis
The letter M checks how far your cancer cells have spread:
- M0 — no cancer cells seen outside of your breast
- M0 (i+) — small amount of cancer cells found in your blood, bone marrow, or very small areas (0.2 millimeters) seen in certain lymph nodes
- M1 — cancer spreads to distant organs like your brain, lungs, or liver
5-Year Survival Rates
The 5-year survival rate can tell you how many people are still alive five years after breast cancer diagnosis. But the numbers depend on your breast cancer type, stage, and treatment.
With treatment, here are some general rates:
- About 99 out of 100 people live five years with local breast cancer.
- Almost 87 out of 100 people live five years with regional breast cancer.
- Almost 32 out of 100 people live five years with distant breast cancer.
- On average, about 91 out of 100 people live five years for all breast cancer stages combined.
Some people can live much longer. Keep in mind the rates can only guess (estimate) what will happen. The numbers can't predict your age, overall health, or treatment success.
Talk to your doctor about the best treatment for your breast cancer. They'll help you better understand survival rates and what they mean for you.
Find support
You may have a lot of questions about your breast cancer. Talk to your doctor and ask about anything you don’t understand. Let your doctor know when you want more information. And tell them if you’re looking for support.
“A good understanding of your breast cancer and treatment options can also help facilitate communication with your loved ones, to help them learn how best to support you during your treatment," says Handy.
You can find support at the American Cancer Society, BreastCancer.org, or talk to your doctor about local support groups.
Takeaways
Breast cancer grades and stages tell you how quickly and far your cancer has spread, helping you choose the best treatment. Knowing your cancer stage can help predict how medicines will work and help you plan for the future.
Breast Cancer Stages and Grades FAQs
How are the stages of breast cancer determined?
After surgery, your breast tissue can be tested at a lab. But if you haven’t had surgery, your doctor can rely on a physical exam, imaging tests, and a biopsy.
What stage of breast cancer requires a mastectomy?
You’ll likely get a mastectomy at any stage of breast cancer. Lumpectomy removes part, but mastectomy takes your entire breast out. With stage 4, you may need chemotherapy to shrink the tumor first (neoadjuvant).
What is stage 0 breast cancer?
Stage 0 is the earliest form of breast cancer, with cancer cells found only in your breast ducts. About 2 out of 10 breast cancers are stage 0.
Is Stage 3 breast cancer curable?
With treatment, stage 3 breast cancer can sometimes be cured. Stage 3 tumors may have spread to nearby tissues but not to distant organs.
What stage is multifocal breast cancer?
Multifocal breast cancer isn’t a certain stage. Multifocal means you have many tumors in the same part of your breast.
Is stage 4 breast cancer curable?
Although there’s no cure, many new medications can help treat stage 4 breast cancer. Treatments can help keep your breast cancer under control for months to years.
How long can you live with stage 4 breast cancer?
With treatment, about 32 out of 100 people live five years with stage 4 breast cancer. Keep in mind that everyone is different. How long you live can depend on your breast cancer type, treatment, and more. Talk to your doctor about what to expect with your cancer treatment.
