By MedHeadlines • Mar
8th, 2008 • Category: Breast Cancer,
Cancer, Diet, FDA, Family, Lifestyle, Medical
Research, Obesity, Prevention, Women's Health
A new study published in the March issue
of Cancer Epidemiology, Biomarkers and
Prevention demonstrates that women who
have a recurrence of breast cancer have
almost twice as much estrogen in their
blood than those without a recurrence despite
treatment with anti-estrogen drugs.
The study’s findings point to the possibility
that high levels of estrogen contribute to
a recurrence of breast cancer in the same fashion
as they contribute to the initial development
of the disease. “While this makes sense,
there have been only a few small studies that
have looked at the link between sex hormones
in the blood and cancer recurrence,” said
Cheryl L. Rock, Ph.D., the lead author of the
study. “This is the largest study to
date and the only one to have included women
taking agents such as tamoxifen to reduce estrogen’s
effect on cancer growth” she added.
The study’s results suggest the need
for women who have been treated for breast
cancer to do as much as they can to reduce
the amount of estrogen in their bodies, such
as maintaining a high level of regular exercise
and keeping the weight down.
Study participants were taken from a larger
dietary intervention trial, Women’s Healthy
Eating and Living Study (WHEL), which evaluated
3,088 women who were previously treated for
early stage breast cancer, but were cancer-free
when they entered the study. Participants in
WHEL were randomly divided into 2 groups, one
eating normal healthy diet as recommended by
the FDA guidelines, and the second group following
diet high in fruits, vegetables, and fiber.
After a seven year follow up, both groups showed
the same rate of breast cancer recurrence.
Researchers therefore determined that a normal
diet following FDA guidelines is adequate.
The current case-control study involved WHEL
participants, 153 of whom were cancer-free
and 153 with cancer recurrence. Women were
matched for body size, age, ethnicity, tumor
size and chemotherapy. Researchers analyzed
the levels of estradiol and testosterone,
both protein-bound and free.
It was determined that increased levels of
estradiol, protein-bound and free-circulating,
were associated with significantly higher
incidence of breast cancer recurrence. It
was also found that women with cancer recurrence,
had more than twice the amount of estradiol
as compared to those who remained cancer-free.
No association was found between breast cancer
recurrence and the levels of SHBG and testosterone.
The study was funded by The Walton Family
Foundation, the National Cancer Institute,
and the National Institutes of Health.
Source: American Association for Cancer Research
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