Breast Cancer: Better Treatments Save More Lives
by Carol Lewis
Two different women. The same deadly disease. One
thought she couldn't get it. The other was told she didn't have it. Both
opinions were wrong.
In 1994, one week before turning 35, Cathy Young
received the devastating news. "I thought people had to be in their
50s to get cancer," the Oak Grove, Mo., resident says. "And then
it happened to me."
Linda Hunter, 42, recalls that in January 1995, her
mammogram results came back normal. But skin changes on one of her breasts
compelled her to seek a second, third and fourth opinion--all of which
supported the initial mammogram findings. Her tenacity finally paid off
when a fifth doctor she visited detected a rare form of the disease.
Every three minutes a woman in the United States
learns she has breast cancer. It is the most common cancer among women,
next to skin cancers, and is second only to lung cancer in cancer deaths
in women. Only 5 to 10 percent of breast cancers occur in women with a
clearly defined genetic predisposition for the disease. The overall risk
for developing breast cancer increases as a woman gets older.
Although treatment is initially successful for many
women, the American Cancer Society (ACS) says that breast cancer will
return in about 50 percent of these cases.
"It's hard to say that things are back to
normal when one survives breast cancer," says Young, "because a
survivor always has a fear that one day the cancer may return."
New drugs, new treatment regimens, and better
diagnostic techniques have improved the outlook for many, and are
responsible, according to ACS, for breast cancer death rates going down.
"Women have greater options in breast cancer
treatment compared to a decade ago," says Harman Eyre, M.D., chief
medical officer for ACS. "New drugs and procedures open up a whole
new era of effective treatment."
Breast Cancer Treatments
Breast cancer can be treated with surgery, radiation
and drugs (chemotherapy and hormonal therapy). Doctors may use one of
these or a combination, depending on factors such as the type and location
of the cancer, whether the disease has spread, and the patient's overall
health.
Most women with breast cancer will have some type of
surgery, depending on the stage of the breast cancer. The least
invasive, lumpectomy (breast-conserving surgery), removes only the
cancerous tissue and a surrounding margin of normal tissue. Removal of the
entire breast is a mastectomy. A modified radical mastectomy includes the
entire breast and some of the underarm lymph nodes. The very disfiguring
radical mastectomy, in which the breast, lymph nodes, and chest wall
muscles under the breast are removed, is rarely performed today because
doctors believe that a modified radical mastectomy is just as effective.
While removing underarm lymph nodes after surgery is
important in order to determine if the cancer has spread, this procedure
may add chronic arm swelling and restricted shoulder motion to the
discomforts of the overall treatment. But a new method, sentinel node
biopsy, still under investigation, allows physicians to pinpoint the first
lymph node into which a tumor drains (the sentinel node), and remove only
the nodes most likely to contain cancer cells.
To locate the sentinel node, the physician injects a
radioactive tracer in the area around the tumor before the mastectomy. The
tracer travels the same path to the lymph nodes that cancer cells would
take, making it possible for the surgeon to determine the one or two nodes
most likely to test positive. The surgeon will then remove the nodes most
likely to be cancerous.
Radiation therapy is treatment with high-energy rays
or particles given to destroy cancer. In almost all cases, lumpectomy is
followed by six to seven weeks of radiation, an integral part of
breast-conserving treatment. Although radiation therapy damages both
normal cells and cancerous cells, most of the normal cells are able to
repair themselves and function properly.
Radiation therapy can cause side effects such as
swelling and heaviness in the breast, sunburn-like skin changes in the
treated area, and lymphedema (swelling of the arm due to fluid buildup) if
the underarm lymph nodes were treated after a node dissection.
Drug Options Expand
Drugs are used to reach cancer cells that may have
spread beyond the breast--in many cases even if no cancer is detected in
the lymph nodes after surgery.
While doctors once believed that the spread of
breast cancer could be controlled with extensive surgery, they now believe
that cancer cells may break away from the primary tumor and spread through
the bloodstream, even in the earliest stages of the disease. These cells
cannot be felt by examination or seen on x-rays or other imaging methods,
and they cause no symptoms. But they can establish new tumors in other
organs or the bones. The goal of drug treatment, even if there's no
detectable cancer after surgery, is to kill these hidden cells. This
treatment, known as adjuvant therapy, is not needed by every patient.
Doctors will make recommendations regarding specific types of therapy
based on the stage of the breast cancer.
FDA has approved several new drugs and new uses for
older drugs in recent years that improve the chances of successfully
treating breast cancer. These drugs include:
Herceptin: About 30 percent of
women with breast cancer have an excess of a protein called HER2, which
makes tumors grow quickly. A genetically engineered drug, Herceptin
(trastuzumab), binds to HER2 and kills the excess cancer cells,
theoretically leaving healthy cells alone.
Herceptin, made by Genentech Inc., San Francisco,
Calif., and approved by FDA in September 1998, is an intravenous treatment
that is used alone in patients who have had little success with other
drugs, or as a first-line treatment in combination with the drug Taxol
(paclitaxel).
Recent follow-up research shows that Herceptin, in
combination with chemotherapy, also may modestly extend the lives of
terminal breast cancer patients. Updated survival figures reported from a
two-year study by one of the drug's key developers from the University of
California at Los Angeles showed an improvement in survival (about 4
months on average) in those getting Herceptin. Scientists say that while
the improvement is small-about four months on average-it is especially
noteworthy in a disease that until now has eluded many efforts to slow its
progression to death.
Selection of patients who are most likely to benefit
from Herceptin is important because of the possible serious risks from the
drug, including weakening of the heart muscle that can lead to congestive
heart failure. It is not known whether Herceptin has beneficial effects in
women with normal levels of the HER2 protein.
FDA also approved in September 1998 a test called
DAKO HercepTest to measure HER2 protein in tumors.
Nolvadex: A drug that has been used
as a breast cancer treatment for more than 20 years, Nolvadex (tamoxifen
citrate) was approved by FDA in October 1998 for breast cancer risk
reduction in high-risk women.
Doctors know that estrogen promotes the growth of
breast cancer cells. Tamoxifen interferes with the activity of estrogen by
slowing or stopping the growth of cancer cells already present in the
body. As adjuvant therapy, tamoxifen has been shown to help prevent both
the original breast cancer from returning, and also the development of new
cancers in the other breast.
A National Cancer Institute study showed that the
drug reduced the short-term chance of getting breast cancer by 44 percent
in women who were judged to be at increased risk for the disease. FDA
emphasizes, however, that tamoxifen, manufactured by Zeneca Pharmaceutical
Inc., Wilmington, Del., will not eliminate breast cancer risk completely,
and should be used only following a medical evaluation of individual risk
factors.
Due to potentially serious side effects, including
endometrial (lining of the uterus) cancer and blood clots in major veins
and the lungs, the American Society of Clinical Oncology recommends that
patients talk with their regular health-care providers to determine
whether individual medical circumstances and histories are appropriate for
considering use of tamoxifen.
Xeloda: Xeloda (capecitabine), made
by Hoffmann-La Roche, Nutley, N.J., was approved by FDA in April 1998 for
the treatment of breast cancer that has spread to other parts of the body
(metastasized) and is resistant to both paclitaxel and an
anthracycline-containing regimen. Xeloda does not kill the cancer cells
directly. Instead, once the drug enters the cancer cells, it is
metabolized to 5-fluorouracil (5-FU), a drug routinely used for breast
cancer. The advantage of Xeloda, in addition to the convenience of its
pill form, is that cancer cells actively convert it to 5-FU, but normal
cells convert very little to 5-FU.
Taxotere: In May 1996, FDA gave
accelerated approval to Taxotere (docetaxel) to treat patients whose
locally advanced or metastasized breast cancer has progressed despite
treatment with other drugs. The approval was conditional on the
manufacturer, Rhone-Poulenc Rorer Pharmaceuticals, Inc., Collegeville,
Pa., conducting additional studies. In June 1998, after additional studies
confirmed its safety and effectiveness, the drug was granted full FDA
approval.
In addition to these newer drugs, combinations of
the anticancer drugs Cytoxan (cyclophosphamide) and Adriamycin
(doxorubicin), with or without Adrucil (fluorouracil), may be used to
treat breast cancer.
Chemotherapy (drug treatment) is given in cycles,
with each period of treatment followed by a recovery period. The total
course of chemotherapy can last three to six months, depending on the
drugs and how far the cancer has spread.
Kelly Munsell of Tucson, Ariz., took the combination
Adriamycin and Cytoxan in six cycles, spaced three weeks apart, after
doctors diagnosed her breast cancer in 1996 at age 27.
"Chemo for me was torture," Munsell
recalls, describing profuse vomiting and severe weight gain as two of the
serious side effects. But despite the discomfort, Munsell, whose mother
and grandmother both died of breast cancer, is glad she underwent the
grueling treatment two years ago. "My recent battery of tests came
back negative for cancer," she says.
In addition to the drugs actually battling the
disease, there also is help for patients in severe pain from cancer. FDA
approved Actiq (oral transmucosal fentanyl citrate) in November 1998 as a
treatment specifically for cancer patients with severe pain that breaks
through their regular narcotic therapy. A narcotic more potent than
morphine, Actiq is in the form of a flavored sugar lozenge that dissolves
slowly in the mouth. Actiq is approved for patients already taking at
least 60 milligrams of morphine per day for their underlying persistent
cancer pain.
Looking Ahead
It is important for every woman to consider herself
at risk for breast cancer, ACS says, simply because she's female. At the
same time, however, studies continue to uncover lifestyle factors and
habits that can alter that risk, and many new chemotherapy drugs and drug
combinations continue to be developed and tested in clinical trials. Drugs
and procedures currently under investigation include bisphosphonates (a
group of drugs routinely used to treat osteoporosis), monoclonal
antibodies (similar to Herceptin), and angiogenesis inhibitors (drugs that
block the development of blood vessels that nourish cancer cells).
"While death rates from breast cancer are
falling, and while there are a number of exciting new strategies being
developed," says Michael A. Friedman, M.D., former FDA deputy
commissioner and cancer research specialist, "we recognize that a
great deal more needs to be done."
Mammography: A Lifesaving Step
The American Cancer Society says that the best
strategy for successfully beating breast cancer is to follow guidelines
for early detection. Currently, the most effective technique for early
detection is screening mammography, an x-ray procedure that can detect
small tumors and breast abnormalities up to two years before they can be
felt and when they are most treatable. (See "FDA Sets Higher
Standards for Mammography" in the January-February 1999 FDA
Consumer.)
Studies show that regular screening mammograms can
help decrease the chance of dying from breast cancer. Finding a breast
tumor early may mean that a woman can choose breast-saving surgery.
Furthermore, she may not have to undergo chemotherapy.
Stages of Breast Cancer
Stages of breast cancer, according to the American
Cancer Society, indicate the size of a tumor and how far the cancer has
spread within the breast, to nearby tissues, and to other organs. Specific
treatment is most often determined by the following stages of the disease:
Carcinoma in situ: Cancer is
confined to the lobules (milk-producing glands) or ducts (passages
connecting milk-producing glands to the nipple) and has not invaded nearby
breast tissue.
Stage I: Tumor is smaller than or
equal to 2 centimeters in diameter and underarm (axillary) lymph nodes
test negative for cancer.
Stage II: Tumor is between 2 and 5
centimeters in diameter with or without positive lymph nodes, or tumor is
greater than 5 centimeters without positive lymph nodes.
Stage III: This stage is divided
into substages known as IIIA and IIIB:
- IIIA: Tumor is larger than 5
centimeters with positive movable lymph nodes, or tumor is any size
with lymph nodes that adhere to one another or surrounding tissue.
- IIIB: Tumor of any size has
spread to the skin, chest wall, or internal mammary lymph nodes
(located beneath the breast and inside the chest).
Stage IV: Tumor, regardless of
size, has metastasized (spread) to distant sites such as bones, lungs, or
lymph nodes not near the breast.
Recurrent breast cancer: The
disease has returned in spite of initial treatment.
Carol Lewis is a staff writer for FDA Consumer. This article originally appeared in the FDA Consumer
magazine, published by the U.S. Food and Drug Administration, in the
July-August 1999 issue.
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