Breast cancer is cancer that begins in lobules, ducts, or connective tissue of the breast.
Breast cancer is staged from 0 to 4. The stage reflects tumor size, lymph node involvement, and how far cancer may have spread. Other things, such as hormone receptor status and tumor grade, are also factored into staging.
This information is crucial to making treatment decisions and understanding your general outlook.
Keep reading to learn how breast cancer is staged, how that affects treatment, and what you can expect.
A doctor may suspect breast cancer following a physical examination, mammogram, or other imaging tests. They may then recommend a biopsy, which is the only way to confirm a diagnosis of breast cancer.
The doctor will use the results from your biopsy to assign a “clinical” stage.
Following surgery to remove a tumor, your doctor will be able to share more information with you about lymph node involvement, along with additional pathology reports.
At that time, your doctor will assign a more accurate “pathologic” stage using the TNM scale. Here’s a breakdown of what T, N, and M means:
T relates to tumor size.
- TX. Tumor can’t be assessed.
- T0. No evidence of primary tumor.
- Tis. Tumor hasn’t grown into healthy breast tissue (in situ).
- T1, T2, T3, T4. The higher the number, the larger the tumor or the more it has invaded breast tissue.
N relates to lymph node involvement.
- NX. Nearby lymph nodes can’t be assessed.
- NO. No nearby lymph node involvement.
- N1, N2, N3. The higher the number, the more lymph node involvement.
M relates to metastasis outside the breast.
- MX. Can’t be assessed.
- M0. No evidence of distant metastasis.
- M1. Cancer has spread to a distant part of the body.
The categories are combined to get the stage, but these factors can also affect staging:
Also, tumors are graded on a scale of 1 to 3 based on how abnormal the cancer cells appear. The higher the grade, the more likely it will grow and spread.
Noninvasive breast cancer includes ductal carcinoma in situ (DCIS). Abnormal cells haven’t invaded nearby tissue.
Stage 1 is divided into stages 1A and 1B.
In stage 1A breast cancer, the tumor measures up to 2 centimeters, but there’s no lymph node involvement.
With stage 1B breast cancer, the tumor is less than 2 centimeters, but there are small clusters of cancer cells in nearby lymph nodes.
Stage 1B breast cancer is also assigned if there’s no tumor, but there are small clusters of cancer cells in lymph nodes.
Note: If the tumor is estrogen receptor- or progesterone receptor-positive, it may be staged as 1A.
Stage 2 is divided into stages 2A and 2B.
Stage 2A is assigned for any one of the following:
- no tumor, but one to three lymph nodes under the arm or near the breastbone contain cancer cells
- tumor up to 2 centimeters, plus cancer in lymph nodes under the arm
- tumor between 2 and 5 centimeters, but no lymph node involvement
Note: If the tumor is HER2-positive and also estrogen receptor- and progesterone receptor-positive, it may be classified as stage 1A.
Stage 2B is assigned for either of the following:
- tumor between 2 and 5 centimeters, plus small clusters of cancer in one to three nearby lymph nodes
- tumor larger than 5 centimeters, but no lymph node involvement
Note: If the tumor is HER2-positive and estrogen receptor- and progesterone receptor-positive, it may be classified as stage 1.
Stage 3 is divided into stages 3A, 3B, and 3C.
Stage 3A is assigned for either of the following:
- cancer in four to nine nearby lymph nodes, with or without a tumor
- tumor larger than 5 centimeters, plus small clusters of cancer cells in lymph nodes
Note: If a tumor larger than 5 centimeters is grade 2, estrogen receptor-, progesterone receptor-, and HER2-positive, plus cancer is found in four to nine underarm lymph nodes, it might be classified as 1B.
In stage 3B, a tumor has reached the chest wall, plus cancer may have:
- spread to or broken through the skin
- spread to up to nine lymph nodes under the arm or near the breastbone
Note: If the tumor is estrogen receptor-positive and progesterone receptor-positive, then it might be classified as Stage 1 or 2 depending on the tumor grade. Inflammatory breast cancer is always at least stage 3B.
In stage 3C, there may not be a tumor in the breast. But if there is, it may have reached the chest wall or breast skin, plus:
- 10 or more underarm lymph nodes
- lymph nodes near the collarbone
- lymph nodes under the arm and near the breastbone
Stage 4 is considered advanced breast cancer, or metastatic breast cancer. This means it has spread to distant parts of the body. Cancer may be present in the lungs, brain, liver, or bones.
Recurrent breast cancer
Cancer that returns after successful treatment is recurrent breast cancer.
You may not have symptoms until a tumor is large enough to feel. Other early symptoms may include changes to the size or shape of the breast or nipple, discharge from the nipple, or a lump under the arm.
Later symptoms depend on where the cancer has spread and may include:
- loss of appetite
- weight loss
- shortness of breath
- double vision
- bone pain
- muscle weakness
Even when divided by stage, it’s hard to determine life expectancy for someone with breast cancer because of the following:
- There are many types of breast cancer, and they vary in their level of aggressiveness. Some have targeted treatment, while others don’t.
- Successful treatment may depend on age, other health problems, and treatments you choose.
- Survival rates are estimates based on people diagnosed years ago. Treatment is advancing quickly, so you may have a better life expectancy than people diagnosed even five years ago.
That’s why you shouldn’t take general statistics to heart. Your doctor can give you a better idea of what to expect based on your personal health profile.
The Surveillance, Epidemiology, and End Results Program (SEER) doesn’t track breast cancer survival rates by type or in stages 0 to 4. A relative survival rate compares people with breast cancer to people in the general population.
Following are SEER
|Localized: Has not spread beyond the breast||98.8%|
|Regional: Has spread to nearby lymph nodes or other structures||85.5%|
|Distant: Has spread to distant parts of the body||27.4%|
Stage is an important consideration in determining treatment, but there are others, such as:
- breast cancer type
- tumor grade
- estrogen receptor and progesterone receptor status
- HER2 status
- age and whether you’ve reached menopause
- overall health
Your doctor will consider all this when recommending treatment. Most people need a combination of therapies.
- Breast-conserving surgery (lumpectomy). Your doctor will remove the abnormal tissue plus a small margin of healthy tissue.
- Mastectomy. Your doctor will remove the entire breast and, in some cases, check nearby lymph nodes for cancer.
- Radiation therapy. This treatment may be recommended if you had a lumpectomy.
- Breast reconstruction surgery. You may schedule this procedure immediately or at a later date.
- Hormone therapy (tamoxifen or an aromatase inhibitor). Your doctor may recommend this treatment when DCIS is estrogen receptor- or progesterone receptor-positive.
Stages 1, 2, and 3
- lumpectomy or mastectomy and removal of nearby lymph nodes to check for cancer
- breast reconstruction immediately or at a later date
- radiation therapy, especially if you chose lumpectomy over mastectomy
- hormone therapy for estrogen receptor-positive and progesterone receptor-positive breast cancers
- targeted drugs such as trastuzumab (Herceptin) or pertuzumab (Perjeta) for HER2-positive cancers
- chemotherapy to shrink tumors or slow tumor growth
- surgery to remove tumors or treat symptoms
- radiation therapy to relieve symptoms
- targeted drugs for estrogen receptor-, progesterone receptor-, or HER2-positive breast cancers
- medications to relieve pain
At any stage, you may be able to participate in clinical trials. These research studies can provide you with access to therapies still in development. Ask your doctor about clinical trials that might be a good fit for you.
Complete remission means all signs of cancer are gone.
Sometimes, cancer cells left behind after treatment eventually form new tumors. Cancer can recur locally, regionally, or in distant sites. While this can happen anytime, it’s most likely within the first five years.
After you finish treatment, regular monitoring should include doctor visits, imaging tests, and blood testing to look for signs of cancer.