What is the breast?
The breast is a collection of glands and fatty tissue that lies
between the skin and the chest wall. The glands inside the breast
produce milk after a woman has a baby. Each gland is also called a
lobule, and many lobules make up a lobe. There are 15 to 20 lobes in
each breast. The milk gets to the nipple from the glands by way of
tubes called ducts. The glands and ducts get bigger when a breast is
filled with milk, but the tissue that is most responsible for the size
and shape the breast is the fatty tissue. There are also blood vessels
and lymph vessels in the breast. Lymph is a clear liquid waste product
that gets drained out of the breast into lymph nodes. Lymph nodes are
small, pea-sized pieces of tissue that filter and clean the lymph. Most
lymph nodes that drain the breast are under the arm in what is called
What is breast cancer?
Collections of cells that are growing abnormally or without control
are called tumors. Tumors that do not have the ability to spread
throughout the body may be referred to as “benign” and are not thought
of as cancerous. Tumors that have the ability to grow into other
tissues or spread to distant parts of the body are referred to as
“malignant.” Malignant tumors within the breast are called “breast
cancer”. Theoretically, any of the types of tissue in the breast can
form a cancer, cancer cells are most likely to develop from either the
ducts or the glands. These tumors may be referred to as “invasive
ductal carcinoma” (cancer cells developing from ducts), or “invasive
lobular carcinoma” (cancer cells developing from lobes).
Sometimes, precancerous cells may be found within breast tissue, and are referred to as ductal carcinoma in-situ (DCIS) or lobular carcinoma in-situ (LCIS).
DCIS and LCIS are diseases in which cancerous cells are present within
breast tissue, but are not able to spread or invade other tissues. DCIS
represents about 20% of all breast cancers. Because DCIS cells may
become capable of invading breast tissue, treatment for DCIS is usually
recommended. In contrast, treatment is usually not needed for LCIS.
Am I at risk for breast cancer?
Breast cancer is the most common malignancy affecting women in
North America and Europe. Close to 200,000 cases of breast cancer were
diagnosed in the United States in 2001. Breast cancer is the second
leading cause of cancer death in American women behind lung cancer. The
lifetime risk of any particular woman getting breast cancer is about 1
in 8 although the lifetime risk of dying from breast cancer is much
lower at 1 in 28. Men are also at risk for development of breast
cancer, although this risk is much lower than it is for women.
The most important risk factor for development of breast cancer is
increasing age. As any woman ages, her risk of breast cancer increases.
Risk is also affected by the age when a woman begins menstruating
(younger age may increase risk), and her age at her first
pregnancy(older age may increase risk). Use of exogenous estrogens,
sometimes in the form of hormone replacement treatment (HRT) may
increase breast cancer risk, but use of oral contraceptives most likely
does not increase risk. Family history is very important in determining
breast cancer risk. Any woman with a family history of breast cancer
will be at increased risk for developing breast cancer herself.
Furthermore, known genetic mutations that increase risk of breast
cancer are present in some families; these include mutations in the
genes BRCA1 and BRCA2. Between 3% to 10% of breast cancers may be
related to changes in one of the BRCA genes. Women can inherit these
mutations from their parents.. Genetic testing for mutations should be
considered for any woman with a strong family history of breast cancer,
especially breast cancers in family members less than 50 years, or
strong family history of prostate or ovarian cancer. If a woman is
found to carry either mutation, she has a 50% chance of getting breast
cancer before she is 70. Family members may elect to get tested to see
if they carry the mutation as well. If a woman does have the mutation,
she may choose to undergo more rigorous screening or even undergo
preventive (prophylactic) mastectomies to decrease her chances of
contracting cancer. The decision to undergo genetic testing is a highly
personal one that should be discussed with a doctor who is trained in
counseling patients about genetic testing. For more information on
genetic testing, see Let the Patient Beware: Implications of Genetic Breast-Cancer Testing, Psychological Issues in Genetic Testing for Breast Cancer, and To Test or Not to Test? Genetic Counseling Is the Key.
Some factors associated with breast cancer risk can be controlled
by a woman herself. Use of hormone replacement therapy (HRT), drinking
more than 5 alcoholic drinks/ week, being overweight, and being
inactive may all contribute to breast cancer risk. These are called
modifiable risk factors.It is important to remember that even someone
without any risk factors can still get breast cancer. Proper screening
and early detection are our best weapons in reducing the mortality
associated with this disease. For further information about breast
cancer risk factors, see Breast Cancer Risk Assessment Tool,and Risk Factors and Breast Cancer.
How can I prevent breast cancer?
The most important risk factors for the development of breast
cancer, such as age and family history, cannot be controlled by the
individual. Some risk factors may be in a woman’s control; however.
These include things like avoiding long-term hormone replacement
therapy, having children before age 30, breastfeeding, avoiding weight
gain through exercise and proper diet, and limiting alcohol consumption
to 1 drink a day or less. For women already at very high risk due to
family history, risk of developing breast cancer can be reduced by
about 50% by taking a drug called Tamoxifen for five years. Tamoxifen
has some common side effects (like hot flashes and vaginal discharge),
which are not serious and some uncommon side effects (like blood clots,
pulmonary embolus, stroke, and uterine cancer) which are life
threatening. Tamoxifen isn't widely used for prevention, but may be
useful in some cases. Use of Tamoxifen for prophylactic reasons should
be considered carefully by an individual and her doctor, as its use is
very individualized. For more information on breast cancer prevention,
see Risk and Prevention.
What screening tests are available?
The earlier that a breast cancer is detected, the more likely it is that treatment can be curable. For this reason, we screen for breast cancer
using mammograms, clinical breast exams, and breast self-exams.
Screening mammograms are simply x-rays of the breasts. Each breast is
placed between two plates for a few seconds while the x-rays are taken.
If something appears abnormal, or better views are needed, magnified
views or specially angled films are taken during the mammogram.
Mammograms often detect tumors before they can be felt and they can
also identify tiny specks of calcium that could be an early sign of
cancer. Regular screening mammograms can decrease the mortality of
breast cancer by 30%. The majority of breast cancers are associated
with abnormal mammographic findings. Woman should get a yearly
mammogram starting at age 40 (although some groups recommend starting
at 50), and women with a genetic mutation that increases their risk or
a strong family history may want to begin even earlier. Many centers
are now making use of digital mammograms, which may be more sensitive
than conventional mammography.
Between the ages of 20 and 39, every woman should have a clinical
breast exam every 3 years; and after age 40 every woman should have a
clinical breast exam done each year. A clinical breast exam is an exam
done by a health professional to feel for lumps and look for changes in
the size or shape of the breasts. During the clinical breast exam, you
can learn how to do a breast self-exam. Every woman should do a self
breast exam once a month, about a week after her period ends. About 15%
of tumors are felt but cannot be seen by regular mammographic
In certain populations of women, MRI screening may be recommended.
The American Cancer Society now recommends yearly breast MRI for breast
cancer screening for women who carry a known BRCA 1 or 2 mutation,
those with a very strong family history of breast or ovarian cancer,
and those who have had prior radiation treatment to the chest (for
example, radiation as part of treatment for Hodgkin’s Lymphoma). Other
populations of women who may or may not benefit from MRI screening are
those who have already had breast cancer, those with known lobular
carcinoma in-situ (LCIS), and those with very dense breast
which may be difficult to visualize on mammograms. Decisions regarding
how to screen for breast cancer (with mammograms, MRI, or both) should
be made between an individual and her physician, based on her
individual breast cancer risk profile.
Other screening modalities that are currently being studied
include, ductal lavage, ultrasound, optical tomography, and PET scan.
For more information on these experimental techniques, see Advanced Breast Imaging, Penn Leads International Study on Breast Cancer Detection, and Komen
Foundation Focuses Attention on the Need for Improved Breast Imaging
and Early Detection Technologies: OncoLink Talks with President and CEO
Susan Braun and Director of Grants Anice Thigpen, PhD
What are the signs of breast cancer?
Unfortunately, the early stages of breast cancer may not have any
symptoms. This is why it is important to follow screening
recommendations. As a tumor grows in size, it can produce a variety of
- lump or thickening in the breast or underarm
- change in size or shape of the breast
- nipple discharge or nipple turning inward
- redness or scaling of the skin or nipple
- ridges or pitting of the breast skin
These symptoms do not always signify the presence of breast cancer,
but they should always be evaluated immediately by a healthcare
How is breast cancer diagnosed and staged?
Once a patient has symptoms suggestive of a breast cancer or an
abnormal screening mammogram, she will usually be referred for a
diagnostic mammogram. A diagnostic mammogram is another set of x-rays
with additional angles and close-up views. Often, and ultrasound will
be performed during the same session. An ultrasound uses high-frequency
sound waves to outline the suspicious areas of the breast. It is
painless and can often distinguish between benign and malignant
Depending on the results of the mammograms and/or ultrasounds, your
doctors may recommend that you get a biopsy. A biopsy is the only way
to know for sure if you have cancer, because it allows your doctors to
get cells that can be examined under a microscope. There are different
types of biopsies; they differ on how much tissue is removed. Some
biopsies use a very fine needle, while others use thicker needles or
even require a small surgical procedure to remove more tissue. Your
team of doctors will decide which type of biopsy you need depending on
your particular breast mass.
Once the tissue is removed, a doctor known as a pathologist will
review the specimen. The pathologist can tell if is the cells are
cancerous or not, If the tumor does represent cancer, the pathologist
will characterize it by what type of tissue it arose from, how abnormal
it looks (known as the grade), whether or not it is invading
surrounding tissues, and whether or not the entire lump was removed
during surgery. The pathologist will also test the cancer cells for the
presence of estrogen and progesterone receptors as well as a receptor
known as HER-2/neu. The presence of estrogen and progesterone receptors
is important because cancers that have those receptors can be treated
with hormonal therapies. HER-2/neu expression may also help predict
outcome. There are also some therapies directed specifically at tumors
dependent on the presence of HER-2/nue. See Understanding Your Pathology Report for more information.
In order to guide treatment and offer some insight into prognosis,
breast cancer is staged into five different groups. This staging is
done in a limited fashion before surgery taking into account the size
of the tumor on mammogram and any evidence of spread to other organs
that is picked up with other imaging modalities; and it is done
definitively after a surgical procedure that removes lymph nodes and
allows a pathologist to examine them for signs of cancer. The staging
system is somewhat complex, but here is a simplified version of it:
Stage 0 (called carcinoma in situ)
Lobular carcinoma in situ (LCIS) refers to abnormal cells
lining a gland in the breast. This is a risk factor for the future
development of cancer, but this is not felt to represent a cancer
Ductal carcinoma in situ (DCIS) refers to abnormal cells
lining a duct. Women with DCIS have an increased risk of getting
invasive breast cancer in that breast. Treatment options are similar to
patients with Stage I breast cancers.
Stage I : early stage breast cancer where the tumor is less that 2 cm, and hasn't spread beyond the breast
Stage II : early stage breast cancer in which the tumor is
either less than 2 cm across and has spread to the lymph nodes under
the arm; or the tumor is between 2 and 5 cm (with or without spread to
the lymph nodes under the arm); or the tumor is greater than 5 cm and
hasn't spread outside the breast
Stage III : locally advanced breast cancer in which the
tumor is greater than 5 cm across and has spread to the lymph nodes
under the arm; or the cancer is extensive in the underarm lymph nodes;
or the cancer has spread to lymph nodes near the breastbone or to other
tissues near the breast
Stage IV : metastatic breast cancer in which the cancer has spread outside the breast to other organs in the body
Depending on the stage of your cancer, your doctor may want
additional tests to see if you have metastatic disease. If you have a
stage III cancer, you will probably get a chest x-ray, CT scan and bone
scan to look for metastases. Each patient is an individual and your
doctors will decide what is necessary to adequately stage your cancer.
What are the treatments for breast cancer?
Almost all women with breast cancer will have some type of surgery
in the course of their treatment. The purpose of surgery is to remove
as much of the cancer as possible, and there are many different ways
that the surgery can be carried out. Some women will be candidates for
what is called breast conservation therapy (BCT). In BCT, surgeons
perform a lumpectomy which means they remove the tumor with a little
bit of breast tissue around it, but do not remove the entire breast.
BCT always needs to be combined with radiation therapy to make it an
option for treating breast cancer. At the time of the surgery, the
surgeon may also dissect the lymph nodes under the arm so the
pathologist can review them for signs of cancer. Some patients will
have a sentinel lymph node biopsy procedure first to determine if a
formal lymph node dissection is required. Sometimes, the surgeon will
remove a larger part (but not the whole breast), and this is called a
segmental or partial mastectomy. This needs to be combined with
radiation therapy as well. In early stage cancers (like stage I and
II), BCT (limited surgery with radiation) is as effective as removal of
the entire breast via mastectomy. The advantage of BCT is that the
patient will not need a reconstruction or prosthesis, but will be able
to keep her breast. Some patients with early-stage cancer prefer to
have mastectomy, and this is an appropriate option as well..
More advanced breast cancers are usually treated with a modified
radical mastectomy. Modified radical mastectomy refers to removal of
the entire breast, as well as and dissection of the lymph nodes under
the arm. Sometimes, patients who have modified radical mastectomy will
require radiation treatment afterwards to decrease the risk of the
cancer coming back.
Some patients with DCIS will be candidates for BCT, while others
will require modified radical mastectomy because of the size or
distribution of DCIS cells. Most patients with DCIS who have a
lumpectomy are treated with radiation therapy to prevent the local
recurrence of DCIS (although some of these DCIS patients may be
candidates for close observation after surgery). Patients with DCIS
that have a mastectomy do not need to have the lymph nodes removed from
under the arm.
Your surgeon can discuss your options and the pros and cons of your
needed surgical procedures. Many women who have modified radical
mastectomies choose to undergo a reconstruction. A patient who desires
reconstruction should try to meet with a plastic surgeon before her
mastectomy to discuss reconstruction options. For more information on
breast reconstruction, see Breast Reconstructive Surgery Options.
Even when tumors are removed by surgery, microscopic cancer cells
can spread to distant sites in the body. In order to decrease a
patient's risk of recurrence, many breast cancer patients are offered
is the use of anti-cancer drugs that go throughout the entire body to
eliminate cancer cells that have broken off from the breast tumor and
spread. Many factors go into determining whether an individual patient
should have chemotherapy. Generally, patients with higher stage disease
need chemotherapy; however, chemotherapy can be beneficial even for
patients with early-stage disease. Individual factors such as age,
overall health, and biologic properties of a woman’s breast tumor may
go into decisions regarding whether or not she should have
chemotherapy. There are many different chemotherapy drugs, and they are
usually given in combinations for 3 to 6 months after you receive your
surgery. Depending on the type of chemotherapy regimen you receive, you
may get medication every 2 to 4 weeks. Most chemotherapies used for
breast cancer are given through a vein, so need to be given in an
oncology clinic. Drugs that are commonly used in breast cancer
treatment include adriamycin (doxorubicin), cyclophosphamide, and
taxanes. There are advantages and disadvantages to each of the
different regimens that your medical oncologist will discuss with you.
Based on your own health, your personal values and wishes, and side
effects you may wish to avoid, you can work with your doctors to come
up with the best regimen for your lifestyle.
Generally, chemotherapy is given after surgery for early-stage
breast cancer. Sometimes, chemotherapy may be given before surgery to
shrink large tumors and allow surgery to be more effective. For
patients with stage IV disease, chemotherapy may be given without
surgery, and a variety of different agents may be tried until a
response is achieved.
Breast cancer is often treated with radiation therapy.
Radiation therapy refers to use of high energy x-rays to kill cancer
cells. Patients having radiation usually need to come to a radiation
therapy treatment center 5 days a week for up to 6 weeks to receive
treatment. The treatment takes just a few minutes, and it is painless.
Radiation therapy is used in all patients who receive breast
conservation therapy (BCT). It is also recommended for patients after a
mastectomy who have had large tumors, lymph node involvement, or
close/positive margins after the surgery. Radiation is important in
reducing the risk of local recurrence and is often offered in more
advanced cases to kill tumor cells that may be living in lymph nodes.
Your radiation oncologist can answer questions about the utility,
process, and side effects of radiation therapy in your particular case.
Some newer techniques for radiation therapy are being used in
certain centers. These are ways to reduce the treatment time needed for
radiotherapy, and usually take 1 – 3 weeks instead of 6 weeks, and are
called accelerated partial breast irradiation (APBI). These techniques
may require a patient to have a radioactive implant placed inside the
breast. These techniques are experimental, and are only indicated for
early-stage breast cancer patients.
When the pathologist examines a tumor specimen, he or she may
determine that the tumor is expressing estrogen and/ or progesterone
receptors. Patients whose tumors express estrogen receptors are
candidates for therapy with estrogen blocking drugs. Estrogen-blocking
drugs include Tamoxifen and a family of drugs called aromatase
inhibitors. These drugs are delivered in pill form for 5 - 10 years
after breast cancer surgery. These drugs have been shown to drastically
reduce your risk of recurrence if your tumor expresses estrogen
receptors. They may be accompanied by side effects, however. When
taking Tamoxifen, patients may experience weight gain, hot flashes and
vaginal discharge.. Taking Tamoxifen may also increase risk of serious
medical issues, such as blood clots, stroke, and uterine cancer.
Patients taking aromatase inhibitors may experience bone or joint pain,
and are at increased risk for thinning of the bones (osteopenia or
osteoporosis). Patients taking aromatase inhibitors should have yearly
bone density testing, and may require treatment for bone thinning.
The pathologist also examines your tumor for the presence of
HER-2/neu overexpression. HER-2/neu is a receptor that some breast
cancers express. A compound called Herceptin (or Trastuzumab) is a
substance that blocks this receptor and helps stop the breast cancer
from growing. Patients with tumors that express HER-2/neu may benefit
from Herceptin, and this should be discussed with a medical oncologist
when the treatment plan is decided upon.
Once a patient has been treated for breast cancer, she needs to be
closely followed for a recurrence. At first, you will have follow-up
visits every 3-4 months. The longer you are free of disease, the less
often you will have to go for checkups. After 5 years, you could see
your doctor once a year. You should have a mammogram of the treated and
untreated breasts every year. Because having had breast cancer is a
risk factor for getting it again, having your mammograms done every
year is extremely important. If you are taking Tamoxifen, it is
important that you get a pelvic exam each year and report any abnormal
vaginal bleeding to your doctor.
Clinical trials are extremely important in furthering our knowledge
of this disease. It is though clinical trials that we know what we do
today, and many exciting new therapies are currently being tested. Talk
to your doctor about participating in clinical trials in your area.
This article is meant to give you a better understanding of breast
cancer. Use this knowledge when meeting with your physician, making
treatment decisions, and continuing your search for information. You
can learn more about breast cancer on OncoLink through the related
links mentioned in this article