Questions and answers on breast cancer
This patient guideline has been superseded by a revised version issued Mar. 6, 2001. Copies previously printed or downloaded should be destroyed
GUIDELINE 8. ANTICANCER DRUG TREATMENT
FOR NODE-POSITIVE 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. 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.
Does "drug treatment" mean chemotherapy?
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.
Which 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. 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 your 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, hormonal treatment can have some benefit by itself, especially if your cancer was ER positive.
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. 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?
It is possible that tamoxifen could be beneficial, especially if your cancer was ER positive. However, there is still no proof of this. For this reason, 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.
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 would be recommended only if for some reason you could not take chemotherapy.
My doctor says I am not strong enough to take chemotherapy.
In this situation, hormonal therapy is recommended. It has fewer unpleasant side effects than chemotherapy.
What is the best therapy if my cancer was ER positive?
If your cancer was ER positive, hormonal therapy is usually recommended.
If I take chemotherapy, what drugs will I be taking?
Two combinations have been widely tested and have proved effective in cases like 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?
Frequently, tamoxifen alone is sufficient. The evidence suggests that tamoxifen is at least as effective as chemotherapy, as long as your cancer was ER positive. However, you may get a small additional benefit (4% increased survival after 10 years) from taking chemotherapy and 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 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 given?
There are 3 recommended combinations: CMF, AC and CEF. Premenopausal women can take any of them. Postmenopausal women should take either CMF or AC. All of them have proved effective against cancer.
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.
What are the most common side effects of chemotherapy?
The side effects are described in guideline 7 in this series.
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. For more information on radiotherapy, see guideline 6 in this series.
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.
Tamoxifen has some beneficial side effects, too. It lowers the chance of cancer in the opposite breast, lowers the risk of death from heart disease and stroke, and reduces the risk of osteoporosis — a common cause of brittle bones and fractures in postmenopausal women.
