Dr. MJ Bazos MD,
Node-Negative Breast Cancer
What is node-negative breast cancer?
Node-negative breast cancer means
that no cancer cells from the breast have been found in the lymph nodes
(sometimes called "glands") in the armpit area. If your cancer is node negative,
there is a lower risk of the cancer returning and spreading than if it is node
I will be having surgery
and radiation treatment for breast cancer. Do I need anticancer drug treatment
Although node-negative cancer
indicates a smaller risk of the cancer returning than node-positive cancer,
there is still a risk. Even when it seems certain that the whole tumour has been
removed, cancer still returns elsewhere in the body ("metastasizes") in up to
30% of all women with node-negative breast cancer.
However, this is simply an average.
Some kinds of cancer are more likely to recur than others, and this will
influence your treatment options. Your cancer will be examined and classified as
having a high, medium or low risk of returning, depending on several factors
Its size. The larger
the cancer, the higher the risk. Most cancers smaller than 1 cm in diameter are
at a very low risk of recurring after surgery and radiation.
The type of cells it contains. Some
cell features are found more often in "aggressive" cancers, cancers that are
more likely to recur and spread. Your pathologist will "grade" your cancer from
I to III depending on its cell features. A grade I cancer is less likely to
return than a grade III cancer.
Whether the cancerous cells have
invaded nearby blood vessels and lymph channels. When vessel invasion is found
under the microscope, the cancer is more likely to return.
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. Women with cancers that
have these receptors (ER-positive cancers) are at a slightly lower risk of the
cancer returning. Also, such cancers react differently to treatment than
All these factors
must be considered when judging your overall risk of the cancer returning. This,
in turn, will determine whether you should have additional treatment and, if so,
which treatment is best for you.
What is the risk that the cancer
will return if I have only surgery and radiotherapy, but no additional drug
If your cancer is
classified as low risk, there is less than a 10% chance it will return in the
next 10 years. In other words, it will come back in fewer than 10 women out of
every 100 who have this type of cancer.
If cancer is classified as
intermediate risk, the chance of the cancer returning is somewhere between 10%
and 20%. Additional treatment will reduce this risk.
Women with high-risk cancers have a
greater than 20% risk of the cancer returning and spreading. This risk is
sometimes as high as node-positive breast cancer. For this group also,
additional treatment will reduce this risk.
My cancer has been classified as
low risk. Do I need additional treatment?
No. In your case, additional drug
treatment is not recommended, since only 1 or 2 out of every 100 women would
benefit from it. Your doctor may discuss the use of hormonal therapy with
My cancer is classified
as high risk. What additional treatment is recommended for me?
Chemotherapy is recommended for
all premenopausal women and for postmenopausal women with ER-negative tumours.
Tamoxifen plus chemotherapy is
recommended for postmenopausal women with ER-positive tumours. The increased
toxicity of chemotherapy must be considered.
These treatments are discussed in more
What is recommended
for women with intermediate-risk cancer?
If the cancer is ER positive,
hormonal therapy with tamoxifen is recommended. This treatment is discussed in
more detail below. (ER-negative cancers are usually classified as high risk.)
Chemotherapy provides additional benefit to tamoxifen. However, the magnitude of
the benefit is small, and the increased toxicity of chemotherapy must be
Chemotherapy is treatment
with drugs that kill cancer cells.
My doctor recommends chemotherapy.
What are the pros and cons?
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 there is a good chance that you will benefit from it and are healthy
enough to take it.
women and for women with ER-negative cancers, chemotherapy is the most effective
means available for guarding against a return of the cancer. Since it 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
There are two recommended
combinations of drugs for treating women with node-negative breast cancer: CMF
and AC. Both have proved effective.
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 also 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
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.
What are the most
common side effects of
Side effects can include
- Nausea and vomiting. If you are being
treated with the CMF combination, nausea and vomiting will be mild to moderate
and will last throughout treatment. However, it can be effectively relieved with
medication. If you choose the AC combination, nausea and vomiting are
likely to be more severe, but will be much
- Some weight gain may occur in about 14% of
- Temporary hair loss. Hair loss is complete
with AC. With CMF, 30% of patients have no hair loss at all, and only 40% have
severe hair loss.
- Mild irritation of the eyes, the lining of
the mouth and throat, and inflammation of the bladder.
- Temporary stoppage of monthly periods during
treatment. In older women this may become permanent.
- Temporary suppression of the body's immune
system during treatment. This increases the risk of infection. In a few
individuals (2%), it may cause fever, requiring hospitalization.
- Severe side effects are rare, occurring in less
than 1% of women receiving the usual doses of chemotherapy. However, they do
happen, and chemotherapy can very rarely even be fatal. There is a very small
risk of heart damage with AC. There is also a very small risk of leukemia
developing in later life (perhaps 1 in every 1000 to 10 000 patients).
When should chemotherapy
Chemotherapy should begin as
soon as possible after your operation, usually within 8 weeks.
If I take chemotherapy, do I need
any other treatment?
If you have a
lumpectomy, radiotherapy will also be recommended. If you are having
chemotherapy, the radiotherapy is usually delayed until the chemotherapy is
My doctor has recommended
hormonal therapy. What does this
The ovaries produce hormones such
as estrogens, which can encourage the growth of breast cancers, especially those
that are ER positive. Hormonal therapy with the drug "tamoxifen" interferes with
this process without stopping the body's hormone production.
Tamoxifen has been found to
prolong life in women with breast cancer, and it also reduces the chances of
getting cancer in the opposite breast.
For how long should tamoxifen be
It is recommended that you take
the standard dose of tamoxifen (20 mg) by mouth every day for 5 years.
What are the side effects of
Tamoxifen can cause
temporary hot flashes in up to 20% of patients. Blood clots in the veins will
develop in about 1 in every 100 patients taking tamoxifen. Rarely, these may
pass into the lung, endangering life. Very rarely (about 1 woman in every 500
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
Tamoxifen 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.