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A panel of national and international experts said
that in addition to surgery, most breast cancer patients should receive chemotherapy, hormonal therapy, or radiation therapy to improve their
chances of surviving breast cancer. The panel convened at the three-day
National Institutes of Health (NIH) Consensus Development Conference on
Adjuvant Therapy for Breast Cancer, which was held from November 1 to
November 3, 2000 at the NIH in Bethesda, Maryland. Among the panel’s top
recommendations were chemotherapy for most women with localized breast
cancer and hormonal therapy (most often with the drug tamoxifen) for women whose breast
tumors are found to have estrogen receptors.
Adjuvant therapy is treatment that is given in addition to surgery. Panel chair
Patricia Eifel, MD, Professor of Radiation Oncology at M.D. Anderson Cancer Center in
Houston, Texas, and her colleagues said that a variety of factors should be considered
when determining whether adjuvant therapy should be offered to breast cancer patients.
These factors include:
- The woman’s age
- Tumor size
- Presence or absence of hormone receptors (for
example, many breast cancer tumors have estrogen receptors and are found
to respond to therapies that block estrogen from these receptors, such
as tamoxifen)
- Presence or absence of cancerous lymph nodes
At the conference, the NIH panel made the following recommendations to help clarify
questions from physicians and patients regarding breast cancer treatment options, quality
of life, and new research:
Chemotherapy Recommendations
According to the NIH panel, treatment with
chemotherapy drugs improves a woman’s chances of surviving breast cancer.
Experts said that chemotherapy should be recommended to most
pre-menopausal and post-menopausal women with localized breast cancer,
regardless of whether their cancer has spread to the lymph nodes
or has estrogen receptors.
The panel determined that chemotherapy with antracyclines (such as
doxorubicin (brand name, Adriamycin) and
epirubicin (brand name, Ellence)) show a small survival advantage over chemotherapy regimens that do
not contain anthracyclines. The panel also said that that there is not enough data to
determine whether chemotherapy with taxanes (such as docetaxel
(brand name, Taxotere) or paclitaxel (brand name, Taxol)) is beneficial to women
whose breast cancers do not involve the lymph nodes. There is also not enough evidence to
determine whether dose-intensive treatment (e.g., high dose chemotherapy with stem cell
support) improves a woman’s outcome, compared with standard combination chemotherapy regimens.
Hormonal Therapy Recommendations
The panel recommended that hormonal therapy (most commonly with tamoxifen) be offered
to women whose breast tumors contain estrogen receptors, regardless of age, menopausal
status, tumor size, or whether the cancer had spread to the axillary (underarm) lymph
nodes. The experts said that research has shown that taking tamoxifen for five years is
more beneficial to women than only taking tamoxifen for one or two years.
Currently, there is no evidence that tamoxifen should be used for more than five years
outside of a clinical trial
setting. However, the panel said that this would be an important area for investigation.
The panel acknowledged that there is a small increased risk of developing
endometrial cancer
(cancer of the lining of the uterus) or thrombosis (blood clotting) for women who
take tamoxifen. However, the benefit of treating breast cancer often outweighs these
risks, according to the panel. Tamoxifen may be combined with combination chemotherapy,
especially in pre-menopausal women, to reduce the chances of a recurrence
of breast cancer.
Radiation Therapy Recommendations
Most women who have
breast-conserving surgery (lumpectomy)
undergo radiation therapy following surgery. The panel also recommended post-surgical
radiation therapy for women who undergo mastectomy
if they have large tumors or if four or more lymph nodes are found to be cancerous. The
panel recommended that researchers investigate whether radiation therapy would be
beneficial to women with three or fewer cancerous lymph nodes.
Panel Calls for Further Research
While the NIH panel made recommendations concerning adjuvant breast cancer therapies
(chemotherapy, hormonal therapy, and radiation therapy), the experts said that many of
these adjuvant therapies may have serious short-term or long-term side effects for some
women, including premature menopause, weight gain, mild memory loss, and fatigue.
Therefore, the panel called for further research to investigate quality of life measures
associated with adjuvant breast cancer therapies. The experts said that long-term follow
up was extremely important to understand the full impact of breast cancer treatments.
The panel recommended studies of:
- Combined hormonal therapy
- Hormonal therapy versus chemotherapy
- High-dose chemotherapy
- Chemotherapy with taxanes, such as docetaxel or
paclitaxel
- Factors that predict the effectiveness of
treatments in individual patients
- New drugs, including trastuzumab
(brand name, Herceptin) and bisphosphonates
- Radiation techniques that reduce the dose to
normal tissue such as the heart and lungs
- The effectiveness and side effects of adjuvant therapies in women older than 70 (to
date, most trials have not included a sufficient number of women over age 70)
Additional Resources and References
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