Download Types of Breast Cancer Brochure - HER2 Positive Breast Cancer

TYPES and
FEATURES of
Breast
Cancer
This handout describes the main types of breast cancer and some other ways of classifying breast cancer based on
its features. Knowing the details of your cancer helps you and your doctor decide how to treat it.
Your health care team is your primary resource for information. Only your health care team can give you medical
advice about your treatment. For more information, ask your health care team or visit the websites listed at the end
of the handout.
Main Types of Breast Cancer
The most common types of breast cancer, based on location, are
described here. See page 2 for other important features that help to
classify breast cancer.
Ductal Carcinoma In Situ
The Lymph System
The body’s lymph system
consists of lymph nodes
(clusters of cells that help
fight infection) connected by
lymphatic vessels, which carry
a fluid called lymph. Lymphatic
vessels are located throughout
the body and are one way that
breast cancer cells can travel
from the breast to other areas.
Metastasis
When invasive
cancer enters
blood or lymphatic
vessels, it
can spread
(metastasize)
beyond the breast.
Ductal carcinoma in situ (DCIS) is the name for abnormal
cells found inside a milk duct and still contained
completely within the walls of the duct. (In situ means
“in place.”) DCIS may be called a precancer. Because
it has not spread to any nearby tissue, it is considered
noninvasive. It sometimes develops into invasive
cancer, but doctors cannot predict whether it will. DCIS
is considered stage 0 (the earliest stage) and is highly
curable.
Lobular Carcinoma In Situ
Ducts
(tubes that
carry milk)
Lobules
(glands that
produce milk)
Lobular carcinoma in situ (LCIS) is not a true cancer. It is the name for abnormal
cells growing inside a milk-producing gland, or lobule, of the breast. LCIS is
noninvasive and rarely becomes invasive, but women with LCIS are more likely
than those without it to develop invasive cancer in either breast.
Invasive Ductal Carcinoma
Invasive ductal carcinoma (IDC) starts in a milk duct, and by the time it is
diagnosed, it has spread through the wall of the duct into nearby breast tissue.
Once this happens, it is possible for cancer cells to travel through blood vessels or
the lymph system (see box) to other parts of the body. IDC is the most common type of
breast cancer.
Invasive Lobular Carcinoma
Invasive lobular carcinoma (ILC) starts in a lobule of the breast. At the time of diagnosis, it has spread beyond the
lobule to surrounding breast tissue, and there is a chance that it has also spread to other parts of the body.
Less Common Types of Invasive Breast Cancer
There are other types of invasive breast cancer that do not occur as often as IDC and ILC. One of these is
inflammatory breast cancer, which can cause the breast to become swollen, tender, and red.
Breast Cancer
Grades
Invasive breast cancer is called
grade 1, 2, or 3 (low, intermediate,
or high grade), depending on how
much the cancer cells differ in
appearance from normal cells. Grade
1 cancer cells look the most like
normal cells. The grade of a cancer
gives clues about its behavior; in
general, the higher the grade, the
faster the cancer is growing and the
more likely it is to spread.
Breast Cancer Stages
Stage 0, the earliest stage, is
carcinoma in situ, which is
noninvasive. Stage I includes small
tumors that may have spread to
lymph nodes, but not to distant
sites. Stage II includes larger tumors
and those with more spread to the
lymph nodes, but still no spread
to distant sites. Stage III includes
even larger tumors and those with
extensive spread to lymph nodes, but
still no spread to distant sites. Stage
IV is metastatic cancer, meaning it
has spread to distant organs or to
lymph nodes far from the breast.
Hormone Receptor–Positive or
Hormone Receptor–Negative
HER2-Positive or
HER2-Negative
Triple-Negative and
Triple-Positive
Some breast cancer cells have
receptors that attach to the
hormones estrogen and/or
progesterone. These hormones can
cause the cancer cells to grow. If
your cancer has estrogen receptors
or progesterone receptors, it is called
hormone receptor–positive. If it has
neither, it is hormone receptor–
negative. Hormone receptor–positive
cancer can be treated with drugs
designed to lower the amount of
hormones in your body or to prevent
the receptors on cells from attaching
to the hormones.
The HER2 (human epidermal growth
factor receptor 2) protein is another
kind of receptor found on cells, and
its job is to help cells grow. Some
breast cancer cells have too many
HER2 proteins, making the cancer
grow faster than it would otherwise.
If your cancer has a high number of
HER2 proteins, it is called HER2positive. If it has a normal number,
it is called HER2-negative. HER2positive breast cancer can be treated
with drugs designed to block the
HER2 protein’s ability to make cells
grow.
If your breast cancer has no estrogen
receptors, no progesterone receptors,
and no increased amount of HER2,
it is called triple-negative. If it has
all three of these features, it is called
triple-positive. Triple-positive breast
cancer can be treated with drugs for
hormone receptor–positive cancer
and with drugs for HER2-positive
cancer (and also with conventional
chemotherapy). These targeted drugs
would not be appropriate for triplenegative breast cancer, but triplenegative cancer can still be treated
with conventional chemotherapy.
Doctors determine a breast cancer’s
stage (how far it has progressed) by
looking at the size of the tumor and
how much the cancer has spread.
Hormone Receptor
and HER2 Status
Laboratory tests can show whether
your breast cancer has features
that make it eligible for certain
types of treatment. These targeted
treatments are often given together
with conventional chemotherapy, and
they can affect both cancer cells and
normal cells.
Breast cell
Progesterone
Estrogen
HER2
Nucleus
Progesterone
receptor
Estrogen
receptor
For More Information
In addition to talking with your health care team, you can visit the following
websites to find more information on breast cancer and the type that you have:
• American Cancer Society: www.cancer.org/cancer/breastcancer
• National Cancer Institute: www.cancer.gov/types/breast
• Breastcancer.org: www.breastcancer.org
Unless otherwise indicated, Genentech Inc. is neither affiliated with nor
endorses any of these organizations. The resources listed are meant for
informational purposes only.
© 2015 Genentech USA, Inc. All rights reserved. HPK/113015/0091
References:
American Cancer Society. Breast cancer:
detailed guide. http://www.cancer.org/acs/
groups/cid/documents/webcontent/003090pdf.pdf. Updated August 19, 2015. Accessed
October 16, 2015.
American Cancer Society. Breast Cancer Facts
& Figures 2013-2014. Atlanta, GA: American
Cancer Society Inc; 2013.