Dr. MJ Bazos MD,
Patient Handout
Chemotherapy and
Breast Cancer
What is node-positive breast
cancer?
Node-positive breast cancer means that cancer
cells from the tumour in the breast have been found in the lymph nodes
(sometimes called “glands”) in the armpit area. Although the breast
cancer is removed during surgery, the presence of cancer cells in the lymph
nodes means that there is a higher chance of the cancer returning and
spreading.
I will be having surgery and radiation
treatment for breast cancer. Do I need drug treatment too?
Almost all women with node-positive breast
cancer require drug treatment in addition to surgery and radiation treatment
(radiation is given following lumpectomy). Even when it seems certain that the
whole tumour has been removed, many women die within 10 years from the cancer
returning if they have had only surgery and radiation without drug treatment.
There is now very powerful evidence that drug treatment in addition to surgery
and radiation helps prolong life.
What does “drug treatment”
mean?
Drug treatment can mean either chemotherapy or
hormonal therapy. Chemotherapy uses special drugs to kill cancer cells. Hormonal
therapy uses a different approach. The ovaries produce natural hormones, such as
estrogen, which encourages some cancers to grow. Hormonal therapy interferes
with this process and can stop or slow the growth of cancer cells. There are 2
kinds of hormonal therapy. The first, called “ovarian ablation,”
stops hormone production by destroying the ovaries with radiation treatment or
by removing them surgically. In the second type of hormonal therapy, estrogen is
still produced by the body, but its effect is blocked by a drug called
“tamoxifen.” The recommended treatment depends on individual
circumstances.
What kind of therapy is best for
me?
Several factors have to be considered. These
include the following:
• Your age, and whether you have gone
through menopause (“change of life”). Medication affects cancers
differently before and after menopause.
• Whether your cancer was diagnosed as
“ER positive” or “ER negative.” “ER”
stands for estrogen receptor. This is a receptor or “docking site”
to which estrogen can bind. If a tumour has these receptors (ER-positive
cancer), it means that its growth may be influenced by your body’s natural
hormones. This will affect the type of treatment recommended for
you.
• Your personal choice. For
example, one treatment may be slightly more effective than another but has more
unpleasant side effects, which may affect your choice. You and your doctor will
need to weigh the expected benefits against the possible problems that the
treatments can cause.
Each of the treatments mentioned in the
following columns are discussed in more detail later. The first choices to be
made depend on your age and whether you have passed menopause. Menopause occurs
over a period of time. You should consider yourself postmenopausal when you have
not had your period for a year. Until then, for the purposes of cancer
treatments, you are considered premenopausal. Women who can’t tell (they
may have had their uterus removed) are considered to be postmenopausal after
their 50th birthday.
Read this section if you are
premenopausal
There is strong evidence that chemotherapy using
a combination of drugs can prolong life and is the best choice for you.
Should I have hormonal therapy in addition
to chemotherapy?
Right now, there is not enough evidence to
recommend taking both.
Can I have hormonal therapy instead of
chemotherapy?
A decision to refuse chemotherapy should not be
made lightly. Hormonal therapy is less effective than chemotherapy for your
situation. However, if you are unable or definitely unwilling to have
chemotherapy and your cancer was ER positive, hormonal treatment (ovarian
ablation or tamoxifen) can have some benefit by itself.
If I have chemotherapy, what drugs will I
be taking?
Three combinations have been widely tested and
have proved effective. They are known as CMF, AC and CEF. Research studies are
investigating adding a new class of drug called taxanes to AC chemotherapy, but
the results are inconclusive. The best choice for you depends on your personal
circumstances. Each combination is discussed in detail further
on.
If I have hormonal therapy, what kind will
it be?
If you can’t have chemotherapy, ovarian
ablation (surgical removal or radiation induced destruction of the ovaries) may
be the best choice for you. Although it is seldom used in Canada at present,
ovarian ablation has proved effective in cases like yours. If you are unable or
unwilling to have ovarian ablation and your cancer was ER positive, tamoxifen
can be used. For more information, read the sections on Chemotherapy and
Hormonal Therapy (including ovarian ablation) that follow.
The best treatment for you depends on whether
your cancer was ER negative or ER positive.
My cancer was ER negative.What is the best
treatment for me?
If you are in good general health, chemotherapy
is the best choice for you. Hormonal therapy is not
recommended.
What is the best therapy if my cancer was
ER positive?
If your cancer was ER positive, hormonal therapy
is recommended. Chemotherapy can provide additional benefit to hormonal
therapy.
If I take chemotherapy, what drugs will I
be taking?
Two combinations have been widely tested and
have proved effective in cases such as yours. They are known as CMF and AC. The
best choice for you depends on your own personal circumstances. Each combination
is discussed in detail further on.
If I have hormonal therapy, what kind will
it be?
Treatment with tamoxifen is the recommended
hormonal therapy for you.
If my doctor recommends tamoxifen, do I
also need chemotherapy?
Chemotherapy can provide additional benefit to
tamoxifen. If this possibility is important to you and you are willing to accept
the unpleasant side effects of chemotherapy, this may be an option for you.
Chemotherapy
My doctor recommends chemotherapy. What
are the pros and cons?
Anticancer drugs also affect healthy cells. This
means they can have undesirable side effects, some of which are severe. For this
reason, chemotherapy is recommended only when you are strong enough to take it.
For premenopausal women and for women with ER-negative cancers, chemotherapy is
the most effective means available for guarding against a return of the cancer.
Since chemotherapy can prolong your life, it would be unwise to refuse it
without good reason. As described below, there is some room for choice between
drug combinations in terms of specific side effects and length of
treatment.
How is chemotherapy
given?
There are 3 recommended combinations: CMF, AC
and CEF. Premenopausal women can take any of them. Postmenopausal women can take
either CMF or AC. All of them have proved effective against cancer. Research
studies are investigating adding a new class of drug called taxanes (e.g.,
paclitaxel) to AC chemotherapy. The results are inconclusive. You can discuss
this option with your doctor. The combination you choose is given in
“cycles” as shown below.
• CMF (cyclophosphamide, methotrexate and
5-fluorouracil)
With this choice, you would take
cyclophosphamide by mouth every day for 2 weeks. On the first day of each of
these weeks you would receive methotrexate and 5-fluorouracil by intravenous
injection. Then there is a 2-week “rest period” when no drugs are
given. This completes 1 full cycle. Six cycles are given altogether, for a total
of 6 months of treatment.
• AC (Adriamycin [doxorubicin] and
cyclophosphamide)
With this combination you do not have to take
daily medication. Instead, you would receive the drugs by intravenous injection
and then have a rest period of 21 days (3 weeks) when no drugs are given. On the
22nd day, you would begin the second cycle. Four cycles are given altogether.
The whole treatment lasts a little over 2 months.
• CEF (cyclophosphamide, epirubicin and
5-fluorouracil)
This combination is given in the same way as
CMF. The cyclophosphamide is taken by mouth every day for 2 weeks, and an
intravenous injection of the other 2 drugs is given on the first day of each of
those weeks. This is followed by a 2-week rest period, which completes the
cycle. Six cycles are given altogether for a total of 6 months of treatment.
Usually, when CEF is used, it is recommended that you take an antibiotic to
guard against infection.
• AC followed by paclitaxel AC is
administered as described above. Three weeks after the last cycle of AC,
paclitaxel is given by intravenous injection. Four doses of paclitaxel are
given, one dose every 3 weeks.
What are the most common side effects of
chemotherapy?
Side effects can include the
following:
• If you are being treated with CMF
chemotherapy, nausea and vomiting can be mild to moderate and can last
throughout treatment. However, they can be effectively relieved with medication.
If you choose AC chemotherapy, nausea and vomiting are likely to be more severe
than with CMF, but they will be much briefer in duration. If you are being
treated with CEF chemotherapy, nausea and vomiting can be moderate. However,
they can be effectively relieved with medication.
• Fatigue is common.
• Some weight gain may occur in about 14%
of patients.
• Hair loss is complete with AC and CEF,
but your hair will grow back after completion of chemotherapy. With CMF, 30% of
patients have no hair loss at all, and only 40% have severe hair
loss.
• Mild irritation of the eyes and the
lining of the mouth and throat, and inflammation of the bladder may
occur.
• Temporary stoppage of monthly periods
during treatment may occur. This side effect may become permanent in older
women.
• Temporary suppression of the
body’s immune system may occur during treatment and can increase the risk
of infection. In a few individuals (about 2% to 5%), it may cause fever,
necessitating admission to hospital.
• Severe side effects are rare, occurring
in less than 1% of women receiving the usual doses of chemotherapy. However,
they can happen, and chemotherapy can very rarely even be fatal. There is a very
small risk of heart damage with AC (less than 1%) and a small risk of heart
damage with CEF (1%). There is also a very small risk of leukemia developing in
later life with AC or CMF (perhaps 1 in every 1000 to 10 000 patients) and a
small risk with CEF (1%).
When should chemotherapy
begin?
Chemotherapy should begin as soon as possible
after your operation, usually within 4 to 6 weeks.
If I take chemotherapy, do I need any
other treatment?
If you have had a lumpectomy, you should also
have radiotherapy. If you are having chemotherapy, the radiotherapy is usually
delayed until the chemotherapy is finished.
Hormonal therapy
My doctor has recommended hormonal
therapy. What does this mean?
The ovaries produce hormones such as estrogen,
which can encourage the growth of breast cancer. There are 2 kinds of hormonal
therapy: ovarian ablation, which stops the body’s hormone production, and
the drug tamoxifen, which blocks the action of the body’s
hormones.
What is ovarian
ablation?
Ovarian ablation stops the production of
hormones in the ovaries, in effect causing menopause in premenopausal women.
This is done by removing the ovaries through surgery or by destroying them with
radiation treatment. The effects are permanent.
What are the side effects of ovarian
ablation?
Ovarian ablation produces all of the usual
symptoms of menopause, including hot flashes and mood swings. However, these
symptoms are temporary. There is also a small increased risk of heart disease
and osteoporosis (brittle bones), as happens in all women after
menopause.
How does tamoxifen
work?
Hormones such as estrogens that are produced in
the ovaries can make cancers grow faster, especially those that have estrogen
receptors (ER-positive cancers). Tamoxifen does not stop hormone production but
blocks the hormones from reaching the cancer cells. The drug is taken daily by
mouth. Tamoxifen has proved to be effective in prolonging life in women who have
been treated for breast cancer. It also reduces the chances of getting cancer in
the opposite breast.
For how long should tamoxifen be
taken?
It is recommended that tamoxifen treatment be
continued for 5 years.
What are the side effects of
tamoxifen?
Tamoxifen may cause temporary hot flashes in up
to 20% of patients. In about 1 in every 100 patients, treatment with tamoxifen
may cause blood clots in the veins. Rarely, these can pass into the lung,
endangering life. Very rarely (about 1 woman in every 1000 treated) tamoxifen
can cause cancer in the lining of the uterus (endometrial cancer). For this
reason, women taking tamoxifen should promptly report any vaginal bleeding
— even slight spotting. Very rarely tamoxifen can cause cataracts.
Tamoxifen has some beneficial side effects, too. It lowers the chance of cancer
in the opposite breast and reduces the risk of osteoporosis — a common
cause of brittle bones and fractures in postmenopausal women.