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Work at Home Moms > Breast Cancer Awareness Month
> Breast Cancer Risk Factors
Breast Cancer Risk Factors
To predict when and in whom breast cancer will
strike, scientists must often think like detectives, looking for clues to signal
which women may be more likely than others to develop the disease. These clues
are called "risk factors".
To identify risk factors, scientists
continually examine various trends and patterns among women worldwide who are
diagnosed with the disease. Age, individual and family medical history,
reproductive history, genetic alterations, race, economic status, neighborhood
and workplace exposures to pollutants and lifestyle habits are all examples of
the factors that can be evaluated.
This information tells a scientific story that
helps experts predict with some certainty a woman's odds for developing breast
cancer. It's important to note, however, that this is not an exact science and
that such predictions are not definite.
Having one or two of these risk factors doesn't
mean a woman will develop breast cancer (seven out of ten breast cancers occur
in women with non of the important risk factors, other than simply being a
woman). But knowing her personal risk factor profile and understanding what it
means will help her and her doctor plan a course of action that may reduce her
chances of ever getting the disease or, at least, to detect in its earliest,
most treatable stages.
The Most Common Risk Factors
Age: The
risk of breast cancer increases as a woman grows older. About 82 percent of
breast cancers occur in women age 60 and older. The risk is especially high for
women age 60 and older. Breast cancer is uncommon in women younger than age 35.
Personal History:
Women who have had breast cancer and women with a history of breast
disease (not cancer, but a condition that may predispose them to cancer) may
develop it again.
Family History:
The risk of getting breast cancer increases for a woman whose mother, sister,
daughter, or two or more close relatives had the disease. It is important to
know how old they were at the time they were diagnosed.
The Breast Cancer
Genes: Some individuals, both women and men, may be born with an
"alteration" (or change) in one of the two genes that are important for
regulating breast cell growth. Individuals who inherit an alteration in the
BRCA1 or BRCA2 gene are at an "inherited" higher risk for breast cancer. They
also may pass this alteration on to their children. It is very rare - scientists
estimate that only about 5-10 percent of all breast cancer changes are likely to
develop breast cancer. Women with a family history of breast cancer are
encouraged to speak to a genetics counselor to determine the pros and cons of
genetic testing.
Note: The next five risk
factors all involve estrogen, a hormone that naturally occurs in every woman. At
the time menstruation begins, women start to product larger amounts of estrogen
and will continue to do so until they reach menopause. Estrogen appears to play
a key role in breast cancer. Although estrogen doesn't actually cause breast
cancer, it may stimulate the growth of cancer cells.
Estrogen-related risk factors are:
Having an Early First Period: Women who begin
menstruating before age 12 are at increased risk of developing breast cancer.
The more menstrual cycles a woman has over her lifetime, the more likely she is
to get the disease.
Having a first pregnancy after age 25 or 30:
Although early pregnancies may help lower the chances of getting breast cancer,
particularly before the age of 25, these same hormonal changes after age 35 may
contribute to the incidence of breast cancer.
Having no children: Women who experience
continuous menstrual cycles until menopause are at a higher than average risk.
Use of Hormone Replacement Therapy (HRT): Based
on the Women's Health Initiative Study (2002), women do appear to have an
increased risk of breast cancer while they are on HRT and a short time
thereafter, compared to those who have never used post-menopausal HRT. This is
based on a study of 16,00 healthy post-menopausal women ages 50-79 who were
taking either estrogen plus progestin as HRT, or a placebo (an inactive pill).
Use of Oral Contraceptives (OCs) and Breast
Cancer: Current or former use of OCs among women ages 35 to 64 did not
significantly increase the risk of breast cancer. Data also show that former OC
use does not increase the risk of breast cancer later in life.
For additional information on risk factors,
access the American Cancer Society website,
www.cancer.org, Breast Cancer Facts & Figures 2004.
Information on this page has been, in
large part, reproduced, with permission, from
NBCAM (supported by
an unrestricted educational grant from AstraZeneca Healthcare
Foundation).
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