The Stages of Breast Cancer
NOTE: Although a lot of this information is still valid, The American Joint Committee on Cancer (AJCC) has recently updated their classifications for staging breast tumors.
We will be updating all our articles on staging in the near future. In the meantime, please click HERE for a brief summary of the major changes in January 2018.
If a breast biopsy confirms that breast cancer is indeed the diagnosis, the staging process begins.
The stages of breast cancer are really the ‘extent‘ of breast cancer. So, in order to choose and begin the best treatment, it is necessary to ‘stage’ breast cancer. The staging process shows the progression of breast cancer.
Breast cancer progresses in relatively predictable and consistent ways, so it is possible to categorize breast cancer in terms of “stages”.
There are basically five stages of breast cancer, with some subcategories (even though the stages range from ‘zero’ to ‘four’).
Breast cancer progression tends to be consistent and predictable
There are many ways that breast cancer can develop but most of the time it starts in the breast ducts.
While cancer is still confined to the breast ducts, specialists refer to it as ductal carcinoma in situ, or DCIS. The good news is that if breast screening detects cancer at this in-situ stage, the chance of survival is close to 100%.
As cancer moves into the breast duct wall and finally begins to affect the surrounding breast tissue, specialists call it infiltrative or invasive breast cancer.
If treatment does not occur, breast cancer will usually spread to other areas of the body (metastasize). Very often the first area that cancer usually spreads to is the lymph nodes in the underarm area (the axilla).
Once cancer enters the lymphatic system, it can and usually does spread to other areas of the body. Sometimes this is called ‘distant metastasis’.
Not all breast cancers spread first to the axillary lymph nodes and then to the rest of the body. If the breast tumor occurs near the nipple, cancer may spread first to the ‘internal mammary nodes’ beneath the sternum. And in some cases, the breast cancer can spread via the bloodstream without involving the lymphatic system.
What investigations are necessary for Staging Breast Cancer?
Breast cancer staging almost always involves a bone scan, as breast cancer is highly prone to metastasize to the bones.
During this test, medics inject a small amount of a radioactive substance into the bloodstream, where it eventually collects in the bones. A radiation scanner is then able to detect accumulations of tracer substance in the bones.
If breast cancer spreads beyond the breast, 25% of the time it goes into bones first.
Where does Breast Cancer spread to?
Breast cancer cells seem to prefer to settle into:-
- long bones in the arms and legs
With an ‘osteolytic‘ metastasis, the cancer kind of ‘eats away’ at the bone, creating ‘holes’.
With an ‘osteoblastic‘ bone metastasis, the bone mineral density actually increases, but this can cause the bones to fracture more easily. This requires a little more explanation. Breast cancer metastases tend to be lytic when they are untreated, and then they become densely sclerotic as they respond to treatment.
Even if no treatment is given yet, an osteoblastic metastasis from breast cancer generally indicates that the persons own body is trying to fight cancer with some success.
A CT scan may also be used to check for metastasis to the lungs or liver. A CT scan is essentially an X-ray linked to a computer. The breast cancer doctor injects a contrast dye agent into the bloodstream and this makes any cancer cells in the liver and chest easier to see.
About those lymph nodes.
A surgeon will usually take a lymph node biopsy to determine if the breast cancer has spread to the axillary lymph nodes. This is not always necessary, however. A lymph node biopsy is not usually necessary for DCIS. However, for invasive breast cancer, yes, they do need to check the lymph nodes.
Sometimes, doctors will perform a ‘sentinel node biopsy“, rather than a full lymph node excisional biopsy if the concerns about cancer spread are minimal. Cancer cells tend to appear first in the sentinel node before spreading to the other nodes, or other areas of the body.
What is a ‘primary’ tumor?
The ‘primary’ tumor refers to the original breast tumor. So, any metastases are either ‘secondary’ tumors, or simply ‘metastatic breast cancer’.
Note, when breast cancer spreads to the bones, it is not ‘bone cancer’, it is metastatic breast cancer in the bones.
“Metastatic” describes a breast cancer that has already spread to distant areas and organs of the body. Metastatic cancer is the most advanced ‘stage’ of breast cancer. Furthermore, the most common sites for breast cancer to metastasize to are the:-
Once breast cancer is at this most advanced metastatic (systemic) stage, the odds of completely curing the breast cancer are quite low. (See our post on survival rates for Stage IV Breast Cancer).
The treatment of metastatic breast cancer, after a reasonable effort, will often focus on the quality of life and relieving symptoms rather than a cure.
Conventional stages of breast cancer progression: 0 through IV
As mentioned, there are five basic stages of breast cancer with a couple of sub-categories.
This is a bit of an unclear term which specialists use to describe the development of abnormal cells that are not yet invasive breast cancer. Indeed physicians consider Ductal Carcinoma in situ, or DCIS, stage 0 breast cancer.
Here the malignant cancer cells are present in the lining of the breast
Early-stage breast cancer; Stage 1
Stage 1 breast cancer is an ‘early stage’ breast cancer. There is a considerable difference in medical opinion as to what exactly constitutes
The standard definition of a stage 1 breast tumor is that a certain amount of breast cancer cells invade tissues and structures beyond the duct lining. However, no cancer cells have spread beyond the breast.
Furthermore, the tumor size is less than 2 cm in diameter. If physicians can detect and treat breast cancer before it grows beyond 2cm, the prognosis is very very good.
The average age of diagnosis of a stage 1 breast tumor is about 52 years old. In over 90% of cases, treatment tends to involve breast conservation surgery, followed by radiation therapy.
Most stage 1 breast cancers require lymph node dissection to check for breast cancer spread, usually, around 18 nodes are sampled.
I have a new post on imaging the axilla. Also, there is a post showing micrometastases in lymph nodes. Some good advice about arm symptoms and lymphedema swelling after armpit surgery. We also have a great post on the surgeon’s role in breast cancer. Here is an external link to lymph node dissection surgery.
Chance of stage 1 cancer recurrence or spreading.
Studies estimate the local recurrence rate of stage I breast tumors to be about 3%. The rate of distant recurrence is about 8%.
Luckily, around 72% of women with stage one breast cancer, properly treated, will have no recurrence of breast cancer over 15 years. Furthermore, the estimate for the overall survival rate after 15 years is a little above that, at around 74%.
These statistics are a little old so check out our brand new post on Breast Cancer Survival Rates according to Stage
Stage II Breast Cancer
There are basically four sub-categories of breast cancer within the category of stage II. Breast tumors in the Stage II classification are:
- A breast tumor that is 2cm in diameter or less. BUT the cancer cells have already spread to the lymph nodes.
- OR a breast tumor that is larger than 5 cm but has not yet spread to the lymph nodes.
- OR breast tumors in between 2 cm and 5 cm in diameter -whether there is evidence of spread to the lymph nodes or not.
There are actually quite a number of specific subcategories and letters and numbers to indicate a more precise description of the breast cancer at Stage II. (If you would like to see more details on the staging of breast cancer go to our brand new post HERE).
In summary, stage II breast cancer is of intermediate size and threatening to spread. Without a doubt, staging for stage II breast cancers requires a thorough investigation of potential metastases.
Survival Rates for Stage II Breast Cancer
The average survival rate for stage II breast cancers is about 93% after five years and about 75% after 10 years. The rate of local recurrence is about 16% for stage II breast tumors. Furthermore, only about 16% of stage II breast cancers either have or will develop lymph node metastasis.
See also our new up-to-date survival rates by stage OR our general survival rates for breast cancer
A baseline bone scan is unlikely to detect bone metastasis with stage 2 tumors, but they are usually necessary just to be sure.
Treatment for Stage II Breast Cancer
Incidentally, in around 80% of cases, breast conservation therapy is the treatment of choice for stage II breast tumors.
Studies show that appropriate adjuvant therapy increases the overall survival rate of stage II breast cancers. Indeed, all patients with stage II breast cancer should consider adjuvant therapy with their breast cancer team. This is especially true when there are indications of the beginnings of systemic disease (positive lymph nodes).
So, studies show that adjuvant chemotherapy increases the disease-free interval and overall survival by about 24% and 15% respectively for women with node-positive stage II breast cancer.
Stage III breast cancer; locally advanced
A stage 3 breast cancer is sometimes referred to as a ‘locally advanced’ breast cancer.
Stage III breast cancers are actually a heterogeneous group of cancers but account for about 7% of all initial breast cancer diagnosis.
Basically, a stage III breast cancer is one in which there is:-
- a primary tumor of greater than 5cm in diameter with no apparent metastasis
- OR the tumor is between 2cm and 5cm in diameter with evidence of rather significant metastasis.
Another way of looking at it is that stage III breast cancers either have a large but ‘operable’ (surgically curable) breast tumor (stage IIIa). Or sometimes Stage III breast cancers present with a medium-size breast tumor (2cm to 5cm) which is more difficult to fully treat and cure with surgery alone.
Treatment of Stage III Breast Cancers
Sometimes large breast cancers invade into muscles or attach to major arteries, veins or nerve trunks, which makes them impossible to surgically remove “completely”.
So, for these patients, the treatment usually starts with radiation or chemo to try to shrink it first, before surgery. But even a large (5cm) tumor that has not attached itself onto muscle can, sometimes, be completely removed. There is no direct relationship between tumor size and whether or not it may be treated surgically or not.
Obviously, Stage 3 breast cancers that surgeons can completely remove do tend to have a significantly better prognosis than inoperable stage 3 breast cancers. However, some breast tumors, particularly those that are ER-positive, respond very well to chemotherapy. So well, in fact, that they actually ‘downstage’.
So, it is difficult to predict the overall prognosis for stage 3 breast cancer, as it will vary from individual to individual. If the response to chemotherapy is favorable, the overall survival rate is around 72%.
Lymph Node Involvement in Stage III Breast Cancers
So, there is still a little bit of ambiguity regarding stage III breast cancers. A stage IIIA breast cancer is one in which the tumor is no more than 5 cms across, but with positive metastasis to the axillary lymph nodes. The cancer cells may spread to the lymph nodes behind the sternum. (‘internal mammary lymph nodes).
A little bit about the Internal Mammary Lymph Nodes
The internal mammary nodes are located behind the ribs. Ribs are made of bone, but in the front, they turn into cartilage just before they join the sternum.
So, each rib attaches to the sternum with cartilage and each of these cartilage bars is around 5 cm long. Thus, it can be very difficult to remove an internal mammary node. There is an internal mammary artery and vein along with the lymph ducts and other veins.
If you need to remove an internal mammary node, the cartilage in front needs to be cut out. Cartilage, unfortunately, does not grow back or heal and this will leave a gap which makes the rib essentially useless.
So, it is a judgement call by the surgeon as to whether or not one should attempt a surgical approach to remove internal mammary nodes with positive metastasis. This is because surgical removal is just too damaging to the function of the chest and ribs.
However, electron beam radiotherapy is an effective treatment for internal mammary nodes. The electrons penetrate to about the correct depth to reach the internal mammary nodes.
Treatment of Stage IIIa Breast Cancer
The treatment for women with stage IIIa breast cancers tends to be a modified radical mastectomy and locoregional radiotherapy. (Locoregional means that the medic aims the radiation beam at the location of the tumor and the surrounding region.)
Often, chemotherapy is given as adjuvant therapy, but in some
Stages of Breast Cancer: Stage IIIb
A stage IIIb breast cancer is one in which the
- axillary lymph node metastasis
- internal mammary node metastasis
presenting in such a way as to suggest that total surgical removal is not possible.
There is a unique type of breast cancer, ‘inflammatory breast cancer‘, that causes the breast to appear red and swollen. This is because the cancer cells ‘block’ some of the lymphatic vessels. Inflammatory breast cancers tend to have a poorer prognosis and are generally stage IIIb at least.
Stages of Breast Cancer: Stage IIIc
Stage IIIc breast cancers basically involve tumors of any size with significant metastases to:-
- the lymph nodes behind the sternum
- lymph nodes under the arm
- the lymph nodes above or below the collarbone
The extent and depth of lymph node involvement make these patients unsuitable candidates for surgical treatment as a primary mode of therapy. Chemotherapy is the treatment of choice for women with stage IIIb and IIIc breast cancers.
However, up to 70% of patients with stage III breast cancers who have chemotherapy remain alive and disease-free after 7 years.
Advanced or metastatic breast cancer: stage IV
Stage IV breast cancers indicate the presence of distant metastasis to other parts of the body, such as the liver or bones.
About 5% of women, in 2017 have a stage IV breast cancer at the time of initial diagnosis.
The long term survival rate for stage IV breast cancer tends to be low, but is improving all the time. In 2012 the National Cancer Institute (SEER) statistics show the 5-year survival rate for Stage IV breast cancer to be around 22%.
However, a more recent study shows that 37% of women survive for 3 years after a Stage IV breast cancer diagnosis.
Also, it is important to remember that each case is individual and there is no telling exact survival rates for any of the stages of breast cancer.
Dilemmas of Stage IV Breast Cancer
Indeed, there are many serious and personal questions involving stage IV breast cancer. So, overall survival is less likely, and gains from intensive breast cancer treatment are unfortunately rather modest. A serious consideration is, therefore, ‘quality of life’ during the course of treatment.
These decisions tend to be a dynamic process, based on individual cases, between patients and physicians. Respect needs to be given to the expectations for treatment, the status of the disease and the patient wishes.
Stage IV breast cancers may be ‘recurrences’ following initial treatment
Up to 5% of
Metastatic breast cancer can appear to be a rapid deterioration of a disease that has been present for some time undetected.
But metastatic (Stage IV) breast cancer can also be the result of a recurrence of breast cancer after successful initial treatment. Sometimes the terms ‘local’ and ‘regional’ recurrence indicate a return of breast cancer to the original tumor site ( after surgery) or elsewhere in the breast or contralateral breast.
If the cancer returns in other areas of the body it is a ‘distant’ metastasis or distant recurrence.
For more detail on Stage IV survival rates, recurrence rates and treatment please see our new post HERE.
Investigations for Stages of Breast Cancer
The following procedures may be necessary to check for metastasis:-
- bone scan
- chest Xray
- CAT scan
- MRI scan
- blood tests
So, after a breast cancer diagnosis, while in general, the outlook is favorable (in comparison to other types of cancer), it should really be considered a ‘chronic’ condition.
But the progression is not going to be the same for everyone, even for patients with similar stages of breast cancer presentation. It is SO important to remember that each case is individual. Indeed breast cancer has been known to return even 20 years after a mastectomy, whilst in others, the progression and systemic development of the disease may be rapid.
Are you considering having NO treatment?
Anxiety, fear, panic, anger and sadness are all common emotions following a breast cancer diagnosis. If you are in the middle of a combination of these feelings, today is not a good day to make important decisions.
Here is my quick ‘imagine a way this all gets better’ line of reasoning, to help you. Firstly, treatments are so effective nowadays and very well organized. Cancer research and treatments are improving all the time and the people who treat breast cancer are experienced experts.
Give the team some trust and time to explain things properly and accept the treatments. Do one step at a time, one day at a time, and you will be amazed at the results.
Add onto that the following self-help methods:-
- lots of sleep
- good, healthy fresh food
- daily exercise
- socializing with people
- accepting support from friends and family
- Join some support groups and connect with others facing the same challenges
Each of these is scientifically proven to improve your own body’s immunologic fight against cancer.
- Breast Cancer Screening and Stages Explained
- TNM Stages of Breast Cancer
- TNM Stages of Breast Cancer: Recent Updates
- Breast Cancer Survival by Stage at Diagnosis
- Full Index of ALL our Articles on Breast Cancer Incidence and Survival Rates
- Full Index of ALL our Articles on Breast Cancer Screening
- ALL our Articles on Types of Breast Cancer
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- Iturbe J. Leone, JP, Zwenger AO, Lacava JA, Vallejo CT, Scuteri RR, Cabaleiro SP, Castro J, Leone, BA. (2008) Treatment of stage I breast cancer (T1N0M0): A long-term follow-up study. J Clin Oncol (2008) 26: https://www.ncbi.nlm.nih.gov/pubmed/22050282
- Shenkier T, Weir L, Levine M, Olivotto I, Whelan T, Reyno L. (2004) Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer. Clinical practice guidelines for the care and treatment of breast cancer: 15. Treatment for women with stage III or locally advanced breast cancer. CMAJ. 170(6):983-94. https://www.ncbi.nlm.nih.gov/pubmed/15023926