Breast cancer staging
What is a "stage" of breast cancer?
When it concerns cancer, the word "stage” refers to the extent of the disease. Staging
breast cancer involves both the size of the tumor and whether or not it has spread
to other parts of the body such as the lymph nodes. Staging is very important because
it helps healthcare professionals determine the best
treatment options to fight your cancer.
Stages of cancer start at 0 and go up to 4, but they are written in Roman numerals
(I – IV). The number implies how much the cancer has spread. Generally, a lower
number means the cancer has not spread, or has spread less. A higher number means
the cancer has spread more.
The stages of breast cancer and what they mean
Stage 0 breast cancer.
The tumor has stayed in the part of the breast where it started. The two stage 0
breast cancers, ductal carcinoma in situ (DCIS, cancer in the cells that carry milk)
and lobular carcinoma in situ (LCIS, cancer in the cells of the glands that make
milk), are different and are treated differently
Treatment.
Doctors usually don’t recommend any immediate treatment for women with LCIS. Close
follow-up, however, is essential. Treatment of DCIS varies, but may include surgery
and radiation
The stages of breast cancer and what they mean
Stage I breast cancer.
The tumor has spread into nearby parts of the breast, but not outside of the breast.
The tumor is 2 centimeters or smaller
Treatment.
A local therapy is likely, usually meaning surgery followed by radiation. This surgery
may be a mastectomy, in which case the whole breast is removed. The lymph nodes
under the arm may be removed. If a tumor is caught early, surgery may be able to
remove all of it. And a breast reconstruction may be done after a mastectomy, either
soon after the surgery or later
The stages of breast cancer and what they mean
Stage II breast cancer.
The tumor is between 2 – 5 centimeters, or it has spread outside the breast to the
lymph nodes under the arm on the same side as the breast cancer
Treatment.
Surgery and radiation are the usual treatments. Radiation may be considered even
after a mastectomy. Adjuvant therapy such as hormone therapy or chemotherapy may
be recommended after surgery
The stages of breast cancer and what they mean
Stage III breast cancer.
The tumor is larger than 5 centimeters, or has spread to areas around the breast,
such as the skin of the breast and the collarbone
Treatment.
Again, doctors recommend surgery to remove part or all of the breast (lumpectomy
or mastectomy). Surgery is usually followed by an adjuvant therapy and radiation
therapy. Larger stage cancers may be treated with chemotherapy before surgery as
well, to help shrink the tumor (this is called "neoadjuvant therapy")
The stages of breast cancer and what they mean
Stage IV breast cancer.
The tumor has spread beyond the breast and nearby areas, possibly to the base of
the neck, lungs, liver, bones, or brain
Treatment.
Systemic therapy like chemotherapy is the main treatment. Radiation therapy and
surgery may also be used to provide relief from certain symptoms
What system do doctors use when staging breast cancer?
The Staging System of the American Joint Committee on Cancer, also referred to as
the TNM system, is most often used by doctors to describe a patient's cancer. The
TNM system involves three scores that describe:
- The tumor type
- Whether or not lymph nodes are involved
- How far the cancer has spread
Tumor, Node, and Metastasis (TNM) staging
Primary tumor (T)
|
T0
|
There is no evidence of a tumor
|
|
Tis:
|
The tumor is “in situ,” meaning it has not spread to nearby tissues
|
|
T1
|
The tumor cannot be seen without using imaging techniques
|
|
T2-4
|
The higher numbers indicate the size and extent of the primary tumor
|
Nodes (N)
|
N0
|
The cancer has not spread to the
lymph nodes
|
|
N1-4
|
The cancer has spread to the lymph nodes. The higher numbers indicate how many lymph
nodes are affected and how far away the cancer has spread
|
Metastasis (M)
|
M0
|
No distant metastasis, meaning the cancer has not spread to other organs
|
|
M1
|
Distant metastasis, meaning the cancer has spread to other organs
|
People fighting breast cancer who are in otherwise good health can take part in
clinical trials of other new potential treatments.
Staging is complex, so be sure to ask your doctors and nurses any questions you
have about it.
Learn about breast cancer
risk factors
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