Breast cancer forms when breast cells mutate and grow out of control. There are several types of breast cancer, the most common being infiltrating ductal carcinoma which makes up 80% of cases. Symptoms can include breast lumps, skin changes, discharge from the nipple, and swelling. Diagnostic tests include mammograms, ultrasounds, and MRIs. Treatment options depend on cancer stage and type but may involve surgery to remove cancerous tissue, radiation therapy, hormone therapy, chemotherapy, and targeted therapy.

1. BREAST CANCER

2. DEFINITION
• Breast cancer originates in your breast tissue. It occurs when
breast cells mutate (change) and grow out of control, creating
a mass of tissue (tumor). Like other cancers, breast cancer can
invade and grow into the tissue surrounding your breast. It can
also travel to other parts of your body and form new tumors.
When this happens, it’s called metastasis.

3. TYPES
• There are several different types of breast cancer, including:
• Infiltrating (invasive) ductal carcinoma. Starting in your milk
ducts of your breast, this cancer breaks through the wall of
your duct and spreads to surrounding breast tissue. Making up
about 80% of all cases, this is the most common type of breast
cancer.
• Ductal carcinoma in situ. Also called Stage 0 breast cancer,
ductal carcinoma in situ is considered by some to be
precancerous because the cells haven’t spread beyond your
milk ducts. This condition is very treatable. However, prompt
care is necessary to prevent the cancer from becoming
invasive and spreading to other tissues.

4. • Infiltrating (invasive) lobular carcinoma. This cancer forms in the
lobules of your breast (where breast milk production takes place)
and has spread to surrounding breast tissue. It accounts for 10% to
15% of breast cancers.
• Lobular carcinoma in situ is a precancerous condition in which there
are abnormal cells in the lobules of your breast. It isn't a true cancer,
but this marker can indicate the potential for breast cancer later on.
So, it’s important for women with lobular carcinoma in situ to have
regular clinical breast exams and mammograms.
• Triple negative breast cancer (TNBC). Making up about 15% of all
cases, triple negative breast cancer is one of the most challenging
breast cancers to treat. It’s called triple negative because it doesn’t
have three of the markers associated with other types of breast
cancer. This makes prognosis and treatment difficult.

5. • Inflammatory breast cancer. Rare and aggressive, this type of
cancer resembles an infection. People with inflammatory
breast cancer usually notice redness, swelling, pitting and
dimpling of their breast skin. It’s caused by obstructive cancer
cells in their skin’s lymph vessels.
• Paget’s disease of the breast. This cancer affects the skin of
your nipple and areola (the skin around your nipple).

6. SIGNS AND SYMPTOMS
• Breast cancer symptoms can vary for each person. Possible
signs of breast cancer include:
• A change in the size, shape or contour of your breast.
• A mass or lump, which may feel as small as a pea.
• A lump or thickening in or near your breast or in your
underarm that persists through your menstrual cycle.
• A change in the look or feel of your skin on your breast or
nipple (dimpled, puckered, scaly or inflamed).
• Redness of your skin on your breast or nipple.

7. • An area that’s distinctly different from any other area on
either breast.
• A marble-like hardened area under your skin.
• A blood-stained or clear fluid discharge from your nipple.
• Some people don’t notice any signs of breast cancer at all.
That’s why routine mammograms and are so important.

8. CAUSES
• Age. Being 55 or older increases your risk for breast cancer.
• Sex. Women are much more likely to develop breast cancer
than men.
• Family history and genetics. If you have parents, siblings,
children or other close relatives who’ve been diagnosed with
breast cancer, you’re more likely to develop the disease at
some point in your life. About 5% to 10% of breast cancers are
due to single abnormal genes that are passed down from
parents to children, and that can be discovered by genetic
testing.
• Smoking. Tobacco use has been linked to many different types
of cancer, including breast cancer.

9. • Alcohol use. Research indicates that drinking alcohol can
increase your risk for certain types of breast cancer.
• Obesity. Having obesity can increase your risk of breast cancer
and breast cancer recurrence.
• Radiation exposure. If you’ve had prior radiation therapy —
especially to your head, neck or chest — you’re more likely to
develop breast cancer.
• Hormone replacement therapy. People who use hormone
replacement therapy (HRT) have a higher risk of being
diagnosed with breast cancer.

10. DIAGNOSTIC EVALUATION
• Mammogram. These special X-ray images can detect changes
or abnormal growths in your breast. A mammogram is
commonly used in breast cancer prevention.
• Ultrasonography. This test uses sound waves to take pictures
of the tissues inside of your breast. It’s used to help diagnose
breast lumps or abnormalities.
• Positron emission tomography (PET) scanning: A PET scan
uses special dyes to highlight suspicious areas. During this
test, your healthcare provider injects a special dye into your
veins and takes images with the scanner.

11. • Magnetic resonance imaging (MRI): This test uses magnets
and radio waves to produce clear, detailed images of the
structures inside of your breast.

12. STAGES
• Stage 0. The disease is non-invasive. This means it hasn’t
broken out of your breast ducts.
• Stage I. The cancer cells have spread to the nearby breast
tissue.
• Stage II. The tumor is either smaller than 2 centimeters across
and has spread to underarm lymph nodes or larger than 5
centimeters across but hasn’t spread to underarm lymph
nodes. Tumors at this stage can measure anywhere between 2
to 5 centimeters across, and may or may not affect the nearby
lymph nodes.

13. • Stage III. At this stage, the cancer has spread beyond the point
of origin. It may have invaded nearby tissue and lymph nodes,
but it hasn’t spread to distant organs. Stage III is usually
referred to as locally advanced breast cancer.
• Stage IV. The cancer has spread to areas away from your
breast, such as your bones, liver, lungs or brain. Stage IV
breast cancer is also called metastatic breast cancer.

14. TREATMENT
• Breast cancer surgery
• Breast cancer surgery involves removing the cancerous
portion of your breast and an area of normal tissue
surrounding the tumor. There are different types of surgery
depending on your situation, including:
• Lumpectomy. Also called a partial mastectomy, a lumpectomy
removes the tumor and a small margin of healthy tissue
around it. Typically, some of the lymph nodes — in your breast
or under your arm — are also removed for evaluation. People
who have a lumpectomy often have radiation therapy in the
weeks following the procedure.

15. • Mastectomy. Removal of your entire breast is another option.
In some cases, doctors can perform a nipple-sparing
mastectomy to preserve your nipple and areola (the dark skin
around your nipple). Many women choose to undergo either
immediate or delayed breast reconstruction following their
mastectomy.

16. • Sentinel node biopsy. To identify the sentinel lymph node,
doctors inject a dye that tracks to thefirst lymph node that
cancer would spread to. If that lymph node is cancer-free,
then other lymph nodes don’t need to be removed. If that
lymph node has cancer in it, it may be necessary to remove
additional lymph nodes. Often, there’s more than one sentinel
node identified, but the fewer lymph nodes removed the
lower the chance of developing swelling in your arm
(lymphedema). A sentinel lymph node biopsy can be done
with either a lumpectomy or a mastectomy.

17. • Axillary lymph node dissection. If multiple lymph nodes are
involved by the cancer, an axillary lymph node dissection may
be done to remove them. This means removing many of the
lymph nodes under your arm (your axilla).
• Modified radical mastectomy. During this procedure, your
entire breast is removed in addition to your nipple. Nearby
lymph nodes in your underarm area are also removed, but
your chest muscles are left intact. Breast reconstruction can
often be an option if desired.

18. • Radiation therapy - (also called radiotherapy) is a cancer
treatment that uses high doses of radiation to kill
cancer cells and shrink tumors. At low doses, radiation is used
in x-rays to see inside your body,
• Types of radiation therapy
• The type of radiation therapy that you may have depends on
many factors, including:
• the type of cancer

19. • the size of the tumor
• the tumor’s location in the body
• how close the tumor is to normal tissues that are sensitive to
radiation
• your general health and medical history
• whether you will have other types of cancer treatment
• other factors, such as your age and other medical conditions

20. • External beam radiation therapy
• External beam radiation therapy comes from a machine that
aims radiation at your cancer. The machine is large and may be
noisy. It does not touch you, but can move around you,
sending radiation to a part of your body from many directions.
• External beam radiation therapy is a local treatment, which
means it treats a specific part of your body. For example, if
you have cancer in your lung, you will have radiation only to
your chest, not to your whole body.

21. • Internal radiation therapy
• Internal radiation therapy is a treatment in which a source of
radiation is put inside your body. The radiation source can be
solid or liquid.
• Internal radiation therapy with a solid source is
called brachytherapy. In this type of treatment, seeds, ribbons,
or capsules that contain a radiation source are placed in your
body, in or near the tumor. Like external beam radiation
therapy, brachytherapy is a local treatment and treats only a
specific part of your body.
• With brachytherapy, the radiation source in your body will
give off radiation for a while.

22. • Hormone therapy for breast cancer
• Some types of breast cancer use hormones — such as
estrogen and progesterone — to grow. In these
cases, hormone therapy can either lower estrogen levels or
stop estrogen from attaching to breast cancer cells. Most
often, healthcare providers use hormone therapy after
surgery to reduce the risk of breast cancer recurrence.
However, they may also use it before surgery to shrink the
tumor or to treat cancer that has spread to other parts of your
body.

23. • Immunotherapy for breast cancer
• Immunotherapy uses the power of your own immune system
to target and attack breast cancer cells. Treatment is given
intravenously (through a vein in your arm or hand). Your
healthcare provider might use immunotherapy for breast
cancer in combination with chemotherapy.

24. • Targeted drug therapy for breast cancer
• Some drugs can target specific cell characteristics that cause
cancer. Your healthcare provider might recommend targeted
drug therapy in cases where breast cancer has spread to other
areas of your body. Some of the most common drugs used in
breast cancer treatment include monoclonal antibodies
(like trastuzumab, pertuzumab and margetuximab), antibody-
drug conjugates (like ado-trastuzumab emtansine and fam-
trastuzumab deruxtecan) and kinase inhibitors (such
as lapatinib, neratinib and tucatinib).