The sample of tumor will be examined under a microscope
by a pathologist, who will identify the cells and determine whether
the tumor is benign or malignant.
If the tumor is malignant, additional
tests may be performed to help your physician determine the type of
treatment that will be most effective.
Estrogen Receptors and Progesterone
One of the most common tests is for estrogen and progesterone
receptors. Receptors are areas on the surface of cells to which
substances, such as the hormones estrogen and progesterone, can
bind (much like a lock accepts a key). When the hormone binds to
its receptor, it activates the cell, making it divide.
If a tumor is composed of cells that have
estrogen or progesterone receptors, it is called estrogen receptor
(ER) positive, or progesterone receptor positive, or hormone receptor
positive. The results of this test are important, because ER positive
tumors can be treated with drugs that block the action of the hormones.
Tumors lacking estrogen and progesterone receptors usually cannot
be treated with this class of drugs.
HER-2/neu (c-erb B2)
An oncogene is a gene which when turned on, leads to development
of a cancer. Women with an abnormally high level of an oncogene
called HER-2/neu tend to develop much more aggressive breast cancers.
A test will determine your level of HER-2/neu and help your oncologist
decide if you are a good candidate for treatment with a drug called
There are other factors that are currently being evaluated and may
help determine the tumor's response.
When cells divide, they go through a number of specific steps, or
phases. S-phase is the phase of the cell cycle in which DNA is replicating
(making copies of itself, so that a complete set will go to each
new cell). Having a high percentage of cells in the S-phase indicates
more rapid tumor growth, and a tumor that is more dangerous.
Genes are clusters of DNA that are strung together in long strands
called chromosomes, and form the "blue-prints" that determine
what a cell does and how it works. Cells having an abnormal number
of chromosomes (or an abnormal amount of DNA) are called aneuploid
and may indicate a somewhat worse prognosis.
A suppressor gene is a gene that protects the body against cancer.
If this gene is mutated (damaged), its protective effect may be
lost. Mutated p53 can be detected in the cells of some breast cancers
and is associated with a poorer prognosis.
Vascular or Lymphatic Invasion
One of the factors to consider in anticipating how aggressive a
tumor will be, is the tumor's ability to develop its own system
of blood vessels to help it grow angiogenesis. Microscopic examination
can show if the tumor is invading lymph ducts or blood vessels,
which would indicate a worse prognosis.
Newly developed, still experimental tests can evaluate
a large number of genes in a tumor tissue sample. Studies are underway
to attempt to determine which sets of genes can predict whether
a particular tumor will respond to a specific treatment.
Why more tests? A biopsy can confirm that the diagnosis is cancer,
but it will not show whether the cancer has spread to other parts
of the body. This information is important to determine the stage
of the tumor. To determine this, additional tests may need to be performed,
including chest X-rays, blood tests, CAT scans or MRIs of the abdomen
or other parts of the body, and bone scans. The surgeon may also remove
lymph nodes from your axilla to check them for cancer spread, although
this is generally done at the time that you have your surgery.
CAT scan, CT scan, or Computerized Axial Tomography all mean the
same thing. This test uses ordinary X-rays, and a rotating film/source
system to obtain detailed images of your body. The test is short
MRI or Magnetic Resonance Imaging uses a combination of magnetic
energy and ordinary radio waves to create images of the inside of
your body. Because the MRI unit can feel cramped, notify the technologist
or your physician if you feel uncomfortable in confined spaces.
MRI is painless, and does not expose you to X-ray radiation. The
test takes about an hour.
Some of the more common sites to which breast cancer cells may metastasize,
or spread, include bones. The most effective way to find these metastases
is to perform a nuclear scan. This test is generally done if the
tumor is large, or the lymph nodes are positive and there is a good
chance that tumor cells may be found in other areas of the body.
For this scan, tiny amounts of radioactive
substance are injected into a vein. Once inside the body, the radioactive
substance concentrates in areas where there is an unusually increased
number of blood vessels (a "hot spot") that may correspond
to a new growth of cancer cells.
The PET scan is a newer addition to cancer staging tests. It works
on a principle similar to the bone scan.
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How Stage is
Each cancer is unique, each woman is different, and the combination
of treatment options is practically endless. To help determine who
should get what treatment, cancer specialists rely on staging—a
system that places the cancer into a certain group. The stage of your
tumor is the most important factor in deciding what type of treatment
is best for you.
In simplified form, staging is based on: the size of the tumor; presence
of cancer cells in the lymph nodes; and metastasis, or spread, to
other organs. This is the so-called TNM—tumor, node, metastasis—staging
Tumor size is determined
when the tumor is removed and sent to the pathologist.
Lymph nodes are checked for evidence of
tumor spread at the time of surgery in a procedure called axillary
lymph node dissection.
Metastasis, or spread to other organs,
is assessed with bone scans, X-rays, CAT scans, and blood tests.
Putting all this information together is called staging.
You may find it helpful to think of stage
as degree of risk presented by a particular tumor.
At one end of the scale are the low-risk
situations: very tiny tumors that have not spread to lymph nodes,
and that are composed of cells that are not very aggressive.
Further along are slightly larger tumors,
still smaller than about a half inch (1 cm), still without evidence
of lymph node spread, but often more aggressive.
At the other end of the scale are the situations
that involve the greatest risk: larger tumors that have invaded the
If you are at the low-risk end of the scale,
your treatment may require breast conserving surgical removal of the
tumor plus a course of radiation therapy, and perhaps a less aggressive
form of hormonal therapy or chemotherapy.
Larger tumors may be treated with more aggressive
For high-risk tumors, at the far end of the
scale, there are a wide variety of options, ranging from combination
chemotherapy to dose dense chemotherapy.
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Stages of Breast Cancer
There are several staging systems in use. Here is one of them:
Stage 0 (in situ): Ductal
or Lobular carcinoma in situ, or Paget's Disease of the nipple.
Stage I: Tumor is 2 cm (3/4
inch) or smaller. Axillary lymph nodes are negative and there is
no evidence of distant metastases.
Stage II: Tumor is 2-5 cm
in size (about 3/4 to 2 inches). Axillary lymph nodes may or may
not be positive for cancer. Even if the tumor is smaller than 2
cm, but the lymph nodes are positive, cancer is also considered
Stage III: Tumor is larger
than 5 cm (2 inches) and axillary lymph nodes are positive. Tumor
may extend into the pectoral muscles or into the skin of the breast,
but there are no distant metastases.
Stage IV: If metastasis to
other organs has occurred, cancer is considered Stage IV regardless
of the size of the tumor, or the number of positive axillary lymph
If you had a fine needle aspiration, the pathologist may
be able to identify the general type of cancer and report within an
hour of the biopsy. For a more complete identification of the cells,
a larger sample, such as from a core needle biopsy or surgical biopsy,
is required. This report will generally take several days.
The final pathology report can only be issued
after the tumor is removed during surgery. This report will specify
the size of the tumor, the type of cell the tumor is composed of,
and whether there is tumor spread to lymph nodes. This
information is essential for planning your treatment.
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