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The claims
A persistent internet email rumor has suggested that underarm
antiperspirants cause breast cancer. It also claims that
- Underarm shaving allows cancer-causing substances in
antiperspirants to be absorbed through razor nicks. These substances
are said to keep lymph nodes under the arm from removing cancer-causing
toxins before they get to the breasts.
- Most breast cancers develop in the upper outer quadrant of
the breast because that area is closest to the lymph nodes exposed to
antiperspirants. (A quadrant is 1/4 of the breast, if you think of the
breast as a circle. The upper outer quadrant of the breast is the part
closest to where the arm is attached.)
- Men have a lower risk of breast cancer because they do not
shave their underarms, and their underarm hair keeps chemicals in
antiperspirants from being absorbed.
All of these claims are largely untrue.
Our responses
Do antiperspirants increase a person's risk
of developing breast cancer?
There is no good scientific evidence to support this claim. We
do not find any strong epidemiologic studies in the available medical
literature that report a scientific study that links breast cancer risk
and antiperspirant use.
In fact, a carefully-designed epidemiologic study of this
issue published in 2002 compared 813 women with breast cancer and 793
women without the disease. The researchers found no link between breast
cancer risk and antiperspirant use, deodorant use, or underarm shaving.
Another study published in 2003 reported on responses from
questionnaires sent out to women who had breast cancer. The researcher
reported that younger women who were diagnosed with breast cancer said
they used antiperspirant and shaved their underarms earlier and more
often than women who were diagnosed when they were older. But the study
design did not include a control group of women without breast cancer
and has been criticized by experts as not relevant to the safety of
these underarm hygiene practices.
It is probable that, in general, young women are more likely
than older women to shave their underarms and use antiperspirants,
whether or not they develop breast cancer later. For instance, most
women born in the 1950s and 1960s may have started shaving earlier and
using antiperspirants more often than women born in the 1930s and
1940s. Or, it is possible that many women shave and use antiperspirants
less often as they get older. These are more likely explanations of the
researcher's findings than the suggestion that these practices cause
cancer. Of special note, the study asked about underarm products that
the women were using at the time the questions were answered, not what
they used before they developed breast cancer.
Does using antiperspirant after shaving
allow chemicals to enter the body from the armpit and increase breast
cancer risk?
Razor nicks may increase the risk of skin infection. If the
underarm skin already has an infection, it is possible that some
antiperspirants could cause slight irritation. But it is unlikely that
this is a major source of carcinogens (cancer-causing substances) that
ever reach the breast cells.
Should I be concerned about parabens in
antiperspirants?
In 2004, a small study found traces of substances called
parabens in some samples of breast cancer tumors. Parabens are used in
some underarm products as preservatives and may have entered the breast
through the underarms in these cases. A possible concern is that in
other studies, parabens have been found to have weak estrogen-like
properties. Estrogen is a female hormone known to cause breast cells
(normal and cancerous) to grow and divide. Some conditions that
increase the body’s exposure to estrogen (not having
children, late menopause, obesity, etc.) have been linked to an
increased risk of breast cancer.
But there are some important points to keep in mind about the
2004 findings:
- The researchers looked only for the presence of parabens in
breast cancer samples. The study did not show that parabens caused or
contributed to breast cancer development in these cases -- it only
showed that they were there. What this means is not yet clear.
- While parabens have weak estrogen-like properties, the
estrogens that are made in the body are hundreds to thousands of times
more potent. So, natural estrogens (or those taken as hormone
replacement) are much more likely to play a role in breast cancer
development.
- Parabens are widely used in shampoo, lotions, other
cosmetics, and even foods. This study did not contain any information
to help find the source of the parabens found in breast tissue.
So far, studies have not shown any direct link between
parabens and breast cancer risk. What has been found is that there are
many other compounds in the environment that also mimic
naturally-produced estrogen.
The bottom line is that larger studies are needed to find out
what effect, if any, parabens might have on breast cancer risk. This
topic will no doubt continue to receive scientific attention.
Is it true that antiperspirants keep a
person from sweating cancer-causing toxins out through their underarm
lymph nodes and this results in a build-up of these toxins in breast
tissue?
Lymph nodes help clear bacteria, viruses, and other possible
threats from the body, but the lymph nodes do not release their
by-products through sweating. Sweat glands are not connected to lymph
nodes. Sweat glands are located in the skin, not in the lymph nodes.
Most cancer-causing substances are removed by the kidneys (and released
into urine) and by the liver (and released into bile, which mixes with
and is eliminated with feces).
Are there lymph nodes in the upper outer
quadrant where most breast tumors occur?
Lymph nodes are located throughout the breasts and have an
important role. The underarm (axillary) nodes filter most of the lymph
flowing out of the breast before it goes back into the body's
bloodstream. These nodes are under the arm and breast, near the upper
outer quadrant of the breast, near the collarbone, and along the chest
area under the breastbone.
The breast quadrants are not actually all the same size. About
half of all breast cancers develop in the upper outer part of the
breast, probably because most breast tissue is located in this area.
The number of breast cancers in the upper outer part of the breast is
in proportion to the amount of breast tissue in that area.
There is no evidence to suggest that the location of cancers
within the breast is related to using antiperspirants or underarm
shaving.
Are men less likely to get breast cancer
because antiperspirant gets caught in their underarm hair and is not
absorbed by their skin?
Men are much less likely than women to develop breast cancer,
mostly because men have much less breast tissue than women. Women have
about 100 times more breast tissue than men do and are about 100 times
more likely to develop breast cancer.
Hormones also play a role. Men with metabolic or genetic
conditions that lead to increased estrogen (female hormone) levels have
an increased risk of developing breast cancer. Underarm hair and
antiperspirant absorption have not been linked to male breast cancer
risk.
Why does my doctor tell me not to use
antiperspirant or deodorant on the day of my mammogram?
The reason for this is that many of these products have
aluminum, which is a metal and can show up on a mammogram as tiny
specks in the area. These specks can look like microcalcifications,
which are one of the things doctors look for as a possible sign of
cancer. Avoiding the use of these products helps prevent any confusion
when looking at the mammogram films.
How did this rumor get started and spread?
We don't know who started this rumor. Most people who
forwarded the e-mail did so with good intentions. We do know that this
rumor has been posted on some internet Web sites that sell deodorants
that are not antiperspirants, so these people might benefit financially
from spread of this misinformation.
How can I learn more about breast cancer
risk factors and ways to find breast cancer early, when treatment is
most effective?
Women concerned about breast cancer should know that their
risk of breast cancer is much more likely to be affected by factors
known to affect hormone levels in the body, such as obesity and hormone
replacement therapy after menopause. Women who wish to reduce their
risk of developing or dying from breast cancer should avoid hormone
replacement therapy, maintain a healthy weight, exercise regularly,
avoid drinking too much alcohol, and get regular mammograms.
Ask your doctor, nurse, or other healthcare providers, and
contact your American Cancer Society by telephone at 1-800-ACS-2345
(1-800-227-2345), or visit our Web site (www.cancer.org). We
can give you information about all aspects of cancer, from causes and
prevention, to diagnosis and treatment.
Additional resources
More information from your American Cancer
Society
We have selected some related information that may also be
helpful to you. These materials may be ordered from our toll-free
number, 1-800-ACS-2345 (1-800-227-2345).
National organizations and Web sites*
In addition to the American Cancer Society, other sources of
patient information and support include:
National Cancer Institute
Toll-free number: 1-800-4-CANCER (1-800-422-6237); TYY: 1-800-332-8615
Web site: www.cancer.gov
National Women's Health Information Center (NWHIC)
Toll-free number: 1-800-994-9662; TYY: 1- 800-220-5446
Web site: www.womenshealth.gov
*Inclusion on
this list does not imply endorsement by the American Cancer Society.
References
Darbre PD. Metalloestrogens: an emerging class of inorganic
xenoestrogens with potential to add to the oestrogenic burden of the
human breast. Journal of Applied Toxicology. 2006; 26(3):191-197.
Darbre PD, Aljarrah A, Miller WR, Coldham NG, Sauer MJ, Pope
GS. Concentrations of parabens in human breast tumours. Journal of
Applied Toxicology. 2004; 24(1): 5-13.
McGrath KG. An earlier age of breast cancer diagnosis related
to more frequent use of antiperspirants/deodorants and underarm
shaving. European Journal of Cancer Prevention 2003; 12:479-485.
Mirick DK, Davis S, Thomas, DB: Antiperspirant Use and the
Risk of Breast Cancer. Journal of the National Cancer Institute. 2002;
94: 1578-1580.
National Cancer Institute. Antiperspirants/Deodorants and
Breast Cancer: Questions and Answers. 2008. Available at:
http://www.cancer.gov/cancertopics/factsheet/Risk/AP-Deo. Accessed July
25, 2008.
Rados C. Antiperspirant Awareness: It’s Mostly No
Sweat. FDA Consumer Magazine. July-August 2005. Available at:
http://www.fda.gov/fdac/features/2005/405_sweat.html
Accessed July 25, 2008.
Robb-Nicholson C. By the way, doctor. I recently received an
e-mail warning about a risk for breast cancer associated with using
antiperspirants. Are you familiar with this theory? Is it valid?
Harvard Womens Health Watch. 2001 Mar;8(7):7.
Surendran A. Studies linking breast cancer to deodorants smell
rotten, experts say. Nature Medicine. 2004; 10:216.
Last Medical Review: 08/11/2008
Revised: 08/11/2008
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