Cancer
Risk Not Equal in Both Breasts
A double mastectomy
might not be called for in many cases
In a finding that could
change how physicians identify candidates for a double mastectomy,
new research has found the risk of breast cancer varies dramatically
from one breast to the other.
Researchers studied 252
women with a type of breast lesion called atypical lobular hyperplasia,
which is believed to be a precursor to cancer.
Fifty of the women, or
20 percent, developed breast cancer. Of those, 34 cancers, or 68
percent, occurred in the same region of the same breast where the
lesions were found earlier.
Many physicians believe
atypical lobular hyperplasia in one breast means a much higher rate
of breast cancer developing in either breast, says Dr. David L.
Page, lead study author and a professor of pathology and preventive
medicine at Vanderbilt University School of Medicine in Nashville.
For that reason, physicians
often recommend that women undergo a double mastectomy, or removal
of both breasts, to prevent breast cancer down the line.
"We've been guided by
the belief that this type of lesion is a marker for increased risk
anywhere in either breast," Page says. "We decided 30 years ago
we were going to do a double mastectomy—all or nothing—but
that approach is not totally supported by the facts."
The study appears in a
recent issue of The Lancet.
In an accompanying commentary,
Dr. Sunil Lakhani of the Institute of Cancer Research and Royal
Marsden Hospital in London says the study provides "evidence to
counteract the myth that the risk of invasive carcinoma after a
diagnosis of lobular in situ neoplasia is equal in both breasts."
Dr. Jay Brooks, chief
of oncology and hematology at the Ochsner Clinic Foundation in Baton
Rouge, La., says the study raises interesting questions about the
best course of action when dealing with these lesions.
No
Definitive Statements To Be Made At This Time
"It's a very provocative
finding, and that's good," Brooks says. "But it's still a relatively
small number of patients to make a definitive statement about it."
Furthermore, Brooks adds,
not every woman developed breast cancer in the same breast. According
to the study, 12 women, or 24 percent, developed breast cancer in
the other breast. In 2 percent, the side was unknown.
Until recently, physicians
looked for two major types of precancerous breast lesions, Page
says.
One is ductal carcinoma
in situ, which previous research has shown means a high risk of
developing cancer in that location of the breast, Page says.
The second is lobular
carcinoma in situ, which physicians believed meant a high risk of
developing breast cancer anywhere in either breast, he says. But
this assumption was based on the faulty interpretation of data,
he says.
Atypical lobular hyperplasia
is sometimes called lobular carcinoma in situ. In fact, the two
are distinct types of lesions and should not be lumped together,
Page says.
Both are benign breast
diseases. But atypical lobular hyperplasia lesions tend to be smaller,
he says.
Women with lobular carcinoma
in situ may have an increased risk of breast cancer in both breasts.
And therefore, a double mastectomy may be what is called for.
But atypical lobular hyperplasia
may be something "in between" the ductal and lobular carcinomas
in situ. Women with atypical lobular hyperplasia have an increased
risk of developing breast cancer—if not in the precise location
of the lesions, in the same region of the same breast, Page says.
There
May Be No Need For a Double Mastectomy
That means there may be
no need for a double mastectomy as a preventive measure, he says.
Instead, a single mastectomy, or even a partial mastectomy, may
be all that is necessary.
A partial (segmental)
mastectomy involves the removal of the breast cancer and a larger
portion of the normal breast tissue around the breast cancer (the
areas removed during the surgery are shaded in green).
Surgeons are still working
on developing a more effective method, Page adds. "There's going
to be a lot of controversy here ... I think it should change medical
practice."
Although there are no
precise statistics, about 2 percent to 4 percent of women who get
biopsies are diagnosed with atypical lobular hyperplasia. Those
at highest risk are premenopausal women between the ages of 40 and
60, he says.
Brooks says there is more
to consider than just the type of lesion a woman has when recommending
for or against a mastectomy. Her family history of breast and ovarian
cancer, her genetic risk, and her emotional state play a role.
Some women insist on the
mastectomy because they are so fearful of cancer, he says.
Using the chemotherapy
drug tamoxifen is also a means of reducing breast cancer risk in
women prone to it, he says.
"What this study is showing
is that breast cancer is a disease that in many cases starts off
with precancerous lesions that we can use as a marker and do something
about it," Brooks says.
Always consult your physician
for more information.
New
Breast Cancer Gene Discovered
Researchers hope
it will lead to earlier detection and improved treatment
A new breast cancer gene
discovered by scientists at the National Institutes of Health
(NIH) may help researchers diagnose the disease in its
early stages and treat it more effectively.
The new gene, found in
breast cancer cells and in normal salivary glands, is named BASE
(Breast Cancer And Salivary Gland Expression), says Kristi A. Egland,
a postdoctoral fellow at the NIH and lead author
of the report, published in a recent issue of the Proceedings
of the National Academy of Sciences.
"We have identified the
RNA and the gene that encodes the protein for BASE," says senior
author Dr. Ira Pastan, of the NIH's Laboratory
of Molecular Biology. "The next step is to make an antibody to detect
the protein. That is what Kristi is working on now."
The hope is that an antibody
can be developed that could detect the protein in the bloodstream.
If so, that could prove to be a way to detect breast cancer in the
early stages. Researchers also hope to make a vaccine to kill these
cells that make the unique protein, Pastan says.
"Everyone has this gene,"
Pastan explains. However, the protein made by the gene is secreted
only by breast cancer and salivary gland cells. "In 30 or 40 percent
of breast cancers [as shown in their laboratory studies], the gene
is active and appears to make a protein that is secreted," Pastan
says.
The discovery adds to
a body of literature about genes and breast cancer. For several
years, scientists have known that about 5 percent to 10 percent
of breast cancer cases are thought to be caused by inherited genetic
mutations in two breast cancer genes, BRCA1 and BRCA2.
The genes code for proteins
that have tumor suppressor capabilities, but in women who have mutations
in these genes, the protein is abnormal and does not suppress the
tumors. A blood test can detect these mutations.
Always consult your physician
for more information.
|
February 2003
Cancer
Risk Not Equal in Both Breasts
No
Definitive Statements To Be Made At This Time
There
May Be No Need For a Double Mastectomy
New
Breast Cancer Gene Discovered
High-Risk
Women Benefit Most From Tamoxifen
Online
Resources
In Other Breast Health
News:
High-Risk
Women Benefit Most From Tamoxifen
Breast cancer
therapy's benefit confirmed
For women who have an
increased risk of developing estrogen-dependent breast cancer, preventive
therapy with tamoxifen can significantly reduce their chances of
developing the disease, according to a recent study.
The study, which appears
in the Journal of the National Cancer Institute,
found that high-risk women who took tamoxifen for more than five
years decreased their risk of cancer by as much as 82 percent.
"High-risk women are deriving
substantial benefit from tamoxifen for risk reduction," says Dr.
Victor Vogel, the director of breast cancer prevention at the University
of Pittsburgh School of Medicine and co-author of an editorial accompanying
the study.
Tamoxifen (Nolvadex) is
a type of medication known as a selective estrogen receptor modulator
that reduces and/or stops the effects of estrogen (a female hormone)
in the body. It was developed over 20 years ago and has been used
to treat both advanced and early stage breast cancer. More recently,
tamoxifen is being used as an adjuvant, or additional, therapy following
primary treatment for early stage breast cancer.
Many types of breast cancer
are dependent on estrogen for growth. Tamoxifen works by taking
the place of estrogen in cancer cells, essentially crowding the
estrogen out. Since tamoxifen acts only as a weak estrogen in breast
cancer cells, it slows or prevents cancer cells from growing.
Women considering taking
tamoxifen should consult their physician, as side effects from the
medication are possible. Different women experience side effects
differently. Some of the more common side effects may include:
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-
-
-
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irregular menstrual cycles
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irritation of skin around the
vagina
Less common side effects
may include:
In this study, researchers
compared the rates of breast cancer between 2,700 women who took
tamoxifen therapy for more than six years and 2,700 women who took
a placebo during that time.
The researchers only included
women who had had hysterectomies (surgical removal of the uterus)
in this study, so there would not be a concern about the increase
in the rate of uterine cancer.
Women who were taller
than 5 feet 3 inches, who first menstruated before age 13, who had
no children or who had their first child after the age of 24, and
who still had their ovaries were classified as having a higher risk
of estrogen-dependent breast cancer.
In these high-risk women,
tamoxifen reduced the risk of breast cancer more than 80 percent.
Also, women who had used hormone replacement therapy (HRT) had a
lowered risk of breast cancer if they took tamoxifen, according
to the study.
For low-risk women, the
researchers report no statistically significant difference between
the tamoxifen and placebo groups. The authors theorize that these
low-risk women may have other factors that protect them against
cancer, and do not need added protection from tamoxifen.
Some women definitely
should not take tamoxifen, including women who are at a low
risk of developing breast cancer. Women over 65 and anyone with
a history of clotting should forgo the mediation as they are
already at an increased risk of developing blood clots.
The researchers add that
their findings are preliminary and need to be confirmed in other
studies.
Always consult your physician
for more information.
Online
Resources
(Our Organization is not
responsible for the content of Internet sites.)
American
Cancer Society
The
Lancet
National
Breast Cancer Coalition
National
Cancer Institute
National
Institutes of Health (NIH)
Proceedings
of the National Academy of Sciences
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