Older Women Mysteriously Not Taking Tamoxifen to
Prevent Breast Cancer
Tamoxifen (Nolvadex) can reduce the risk of
developing breast cancer; NCI wanted to know how many women aged 40 to
79 were taking it
Feb. 8, 2010 - Researchers with the National Cancer
Institute (NCI) have found that the prevalence of tamoxifen brand
name, Nolvadex - use for the prevention of breast cancer among older
women without a personal history of breast cancer is very low.
Two reports in radiology journal: Epigenetics may
determine risk of low-dose radiation... and explain mechanisms of aging,
human development, and the origins of cancer, heart disease, mental
illness, etc.
Tamoxifen can reduce the risk of developing breast
cancer in women who are at increased risk for developing the disease.
Details of this survey are published in the February issue of Cancer
Epidemiology, Biomarkers & Prevention, a journal of the American
Association for Cancer Research.
(More about Tamoxifen from National
Cancer Institute below news report.)
The low prevalence of tamoxifen use may stem from
various sources, which were not investigated in this study, according to
the study's coauthor Andrew N. Freedman, Ph.D., chief of the Clinical
and Translational Epidemiology Branch, Division of Cancer Control and
Population Sciences, NCI.
However, he stressed that "counseling individual
women about using tamoxifen to prevent breast cancer must include a
patient's discussion with her physician about the drug's risks and
benefits, as well as consideration of the patient's personal values,
preferences, lifestyle and specific medical situation."
Lead author of this study Erika A. Waters, Ph.D.,
M.P.H., assistant professor at Washington University School of Medicine
in St. Louis, and colleagues at the NCI wanted to gain an understanding
of how many women aged 40 to 79 years were taking tamoxifen for the
prevention of breast cancer.
They answered this question using data from the
National Health Interview Surveys from years 2000 and 2005, which are
nationwide surveys designed to be representative of the entire United
States. The surveys included more than 10,000 women for each year.
"Our results indicated that very few women were
using tamoxifen to prevent breast cancer," said Waters. "However, we
don't know exactly why."
The researchers found that the prevalence of
tamoxifen use in this survey population was very low 0.2 percent in
2000 and 0.08 percent in 2005. The difference between the two years was
not statistically meaningful, according to the researchers.
Freedman and Waters speculated that the drug's low
uptake may be linked to many factors including the fact that tamoxifen
is associated with several side effects. These side effects include hot
flashes, sexual problems, uterine cancer, blood clots and cataracts.
Other possible explanations that the researchers
gave for the low uptake may be -
● physicians are unaware of the drug's availability, physicians are
reluctant to prescribe it,
● patients are reluctant to take it,
● there is a lack of patient or physician education about the drug,
or
● skepticism about whether the benefits outweigh the risks.
It could also be that physicians and patients are,
in fact, very educated and are making very informed decisions, according
to the researchers.
"The decision to use a drug like tamoxifen in women
at high-risk for, but who do not yet have a diagnosis of breast cancer
is not easy. It is dependent upon the woman's personal choice, which can
be influenced by many factors, not just her medical eligibility. There
is no right answer," said Waters, who at the time of the study was a
fellow in the Cancer Prevention Fellowship Program, Center for Cancer
Training, NCI.
Susan Gapstur, Ph.D., M.P.H., vice president of
epidemiology, American Cancer Society, and editorial board member of
Cancer Epidemiology, Biomarkers & Prevention, said that "overall, these
results provide an important snapshot of the very low uptake of
tamoxifen for cancer prevention."
"Although the researchers speculate on a number of
possible explanations, it remains unclear to what extent the low uptake
might be attributed to physician reluctance to prescribe tamoxifen
and/or patient reluctance to take it," said Gapstur.
Tamoxifen (Nolvadexฎ) is a drug, taken
orally as a tablet, which
interferes with the activity of estrogen, a female hormone. Estrogen can
promote the development of
cancer in the breast.
It is used to treat certain types of breast cancer
in women and men. It is also used to prevent breast cancer in women who
have had ductal carcinoma in situ (abnormal cells in the ducts of the
breast) and in women who are at a high risk of developing breast cancer.
Tamoxifen is also being studied in the treatment of other types of
cancer. It blocks the effects of the hormone estrogen in the breast.
Tamoxifen is a type of antiestrogen. Also called tamoxifen citrate.
Tamoxifen citrate is approved by the
Food and Drug Administration (FDA) to treat
breast cancer in women and men. Tamoxifen is also approved to
decrease the chance of developing breast cancer in women who are at high
risk for this disease.
Tamoxifen citrate is also being studied in the
treatment of other types of
cancer.
Risk Factors for Breast Cancer
At present, the factors known to increase a womans
chance of developing breast cancer include age (a womans chances of
getting breast cancer increase as she gets older), a
family history
of breast cancer, an early age at first menstrual period, a late age at
menopause,
a late age at the time of birth of her first full-term baby, and certain
breast conditions.
Feb. 8, 2010 - Researchers with the National Cancer
Institute (NCI) have found that the prevalence of tamoxifen brand
name, Nolvadex - use for the prevention of breast cancer among older
women without a personal history of breast cancer is very low. 
Tamoxifen (Nolvadexฎ) is a drug, taken