Dr. MJ Bazos MD,
Patient
Handout
Chemotherapy &
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 column 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
radiationinduced 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.
Read
this column if you are
postmenopausal
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. For more information, read the sections on
Chemotherapy and Hormonal Therapy (tamoxifen) that
follow.
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 give 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.