Questions and answers on breast cancer
Guideline 7: Anticancer drug treatment for node-negative breast cancer
(revised Jan. 23, 2001)


Questions and answers on breast cancer

Guideline 7. Anticancer Drug Treatment for
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 positive.

I will be having surgery and radiation treatment for breast cancer. Do I need anticancer drug treatment too?

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 outlined below.

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 treatment?

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 tamoxifen.

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 detail below.

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 considered.

Chemotherapy

What is chemotherapy?
Chemotherapy is treatment with drugs that kill cancer cells.

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 there is a good chance that you will benefit from it and are healthy 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 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.

What are the most common side effects of chemotherapy?
Side effects can include the following: