NCCN Guidelines for Patients
Breast Cancer – Metastatic (STAGE IV), Version 2.2017
Hormone receptor–positive cancers
permanently stops the ovaries
from making hormones. Most often, both ovaries
are removed from the body. This surgery is called a
bilateral oophorectomy. Radiation to the ovaries also
stops the making of hormones, but isn’t used often.
temporarily stops the
ovaries from making hormones. It is achieved with
drugs called LHRH (
ormone) agonists. LHRH is a hormone in the
brain that helps control the making of estrogen by
the ovaries. LHRH agonists stop LHRH from being
made, which stops the ovaries from making more
What to expect
. Some endocrine therapies greatly
differ by how they are given and what’s required of
you. An example is one day of surgery versus a few
days of radiation therapy. Some drugs are given
as monthly injections while others are pills that are
taken every day. Your treatment team will give you
more information. Questions to ask about treatment
are listed in Part 4.
For many women, endocrine therapy causes
symptoms of menopause. Menopausal symptoms
include hot flashes, vaginal discharge or dryness,
sleep problems, weight gain, hair thinning, fatigue,
bone loss, and changes in mood. You may have
different symptoms from other women.
Tamoxifen also has two rare but more serious side
effects: 1) cancer of the uterus; and 2) blood clots.
For most women with breast cancer, the benefits of
taking tamoxifen far outweigh the risks. Aromatase
inhibitors don’t cause cancer and very rarely cause
Not all the side effects of endocrine therapy are listed
here. Please ask your treatment team for a list of all
common and rare side effects. If a side effect bothers
you, tell your treatment team. There may be ways to
help you feel better.
Many targeted therapies stop the signals that tell
a cell to grow. Within signal pathways are protein
kinases. Protein kinases are molecules that move
chemicals, called phosphates, from one molecule to
See Figure 8.
The phosphate “turns on”
the next molecule in the signal pathway.
Targeted therapy for hormone receptor–positive
cancers blocks protein kinases. This type of targeted
therapy is called kinase inhibitors.
See Figure 9.
stop the action of CDK (
inase). CDK is a protein kinase within
the cell nucleus. CDK4 and CDK6 promote cancer
growth in hormone receptor–positive cancers. CDK
inhibitors attach to CDK and stop growth signals.
are made in pill form. They
are taken in a 4-week cycle. You will be on treatment
for the first 3 weeks and off treatment for 1 week.
Common side effects include tiredness, nausea,
vomiting, diarrhea, constipation, headache, and hair
loss. Your white blood cell counts may drop. This
may lead to serious infections. Palbociclib can also
cause serious blood clots, and ribociclib, liver and
stop the action of mTOR
apamycin). mTOR is a protein
kinase within a cell’s gel-like substance. Sometimes,
endocrine therapy stops working because mTOR is
turned on. mTOR inhibitors attach to mTOR and stop
Everolimus is a pill that is taken around the same
time every day. Common side effects include
diarrhea, tiredness, mouth sores, skin rash, cough,
and low blood counts. Serious side effects include
other cancers, lung problems, infections, and kidney