Breast cancer is
an uncontrolled
growth of cells
that starts in the
breast tissue.
About one in eight
women in the
United States will
develop the
condition in her
lifetime, according
to the National
Institutes of
Health.
It is the second
most common
cancer in women, after skin cancer, and in
2014 more than 232,000 U.S. women were
diagnosed with the condition, according to
the National Cancer Institute .
Breast cancer is most commonly diagnosed
in women ages 55 to 64. The disease can
also occur in men, but it is much less
common: Male breast cancer accounts for
less than 1 percent of all breast cancer cases,
according to NCI.
Survival rates for breast cancer have
increased in recent years. Between 2004 and
2010, about 89 percent of breast cancer
patients lived for at least five years after their
diagnosis, the NCI says.
Causes
The exact cause of breast cancer — that is,
what causes breast cells to start to grow out
of control — is not known. The combination
of a person's genes and their environment
likely plays a role in the development of the
disease, according to the Mayo Clinic .
In about 5 to 10 percent of breast cancer
cases, genetic mutations are linked to the
disease. For example, women with mutations
in the BRCA genes are at increased risk for
breast cancer. Some studies show that
women with mutations in the BRCA1 gene
have a 50 percent to 70 percent chance of
getting breast cancer by age 70, and women
with mutations in the BRCA2 gene have a 40
percent to 60 percent chance, according to
the Susan G. Komen Foundation , a nonprofit
organization that funds breast-cancer
research and advocates for patients.
Other risk factors include a family history of
breast cancer, starting menstrual periods
before age 12 or going through menopause
after age 55, not having children, having
dense breast tissue, and using hormone
therapy after menopause, according to
the American Cancer Society . However, most
women who get breast cancer don't have any
risk factors for the disease, other than their
gender and age, the ACS says.
Symptoms
Not everyone with breast cancer will have
symptoms before they are diagnosed. But,
according to the Centers for Disease Control
and Prevention, possible symptoms of the
disease include:
A lump in the breast or armpit
A thickening or swelling of the breast
Dimpling of the breast or skin
irritation
Red or flaky skin in the nipple area
Nipple discharge other than breast
milk
It's important to note that even these
symptoms don’t necessarily mean a
malignancy is present and often signal a
benign condition, such as a cyst or infection.
Screening:
Breast cancer screening tests are done on
symptom-free women, with the goal of
catching the disease early. One of the main
screening tests is a mammogram, or an X-
ray of the breast. The United States
Preventive Services Task Force recommends
mammograms every two years for women
ages 50 to 74.
However, exactly when women should start
to get mammograms, and how frequently
they should get them, has been debated. For
example, the American Cancer Society
recommends that women get their first
mammogram starting at age 40, and get
them every year after.
Some studies suggest a benefit to regular
mammogram screening. A 2013 study of
breast cancer patients in Boston, published in
the journal Cancer, found that, among women
who died of the disease, most had not
undergone regular breast cancer screening.
However, some researchers criticized the
study because it did not look at screening
rates among women who survived breast
cancer.
A major concern with breast cancer screening
is that it increases the risk of
"overdiagnosis," that is, diagnosis of cancers
that would not cause noticeable disease
during women's lifetimes. A 2012 study
published in the journal Annals of Internal
Medicine found that up to 25 percent of
women diagnosed with breast cancer through
a mammogram were actually overdiagnosed.
Another study, published in the New England
Journal of Medicine in 2012 , found that, while
mammograms have increased detection of
early-stage breast cancers, they have done
little to reduce the risk of death from
advanced stage breast cancer.
There is also concern that frequent
mammograms increase the chance that a
woman will receive a false positive result:
A 2011 study in the journal Annals of Internal
Medicine found that 61 percent of women
who get yearly mammograms will have at
least one false positive result over a decade.
The CDC recommends that women ages 40
to 49 speak with their doctor about when to
start mammograms, and how often to get
them.
Other screening tests for breast cancer
include a clinical breast exam, in which a
doctor feels for lumps or changes in the
breast, or a self-exam, when a woman
checks her own breasts for lumps or changes
in size or shape. However, neither a clinical
breast exam nor a self-exam have been
found to decrease the risk of dying from
breast cancer, the CDC says. So if women
have these exams, they should also undergo
mammograms as well, if they are in the age
group for which mammograms are
recommended, the CDC says.
Diagnosis
If a screening method reveals possible breast
cancer, follow-up tests are done to confirm
the diagnosis. These include:
Imaging tests such as mammograms,
MRI scans or breast ultrasound. Each of
these methods produces internal pictures
of the breast that help doctors see a
potential mass.
Biopsies, which take cells from
suspicious lumps to study in a pathology
lab to determine if they are malignant.
Cells are extracted through special
needles or during surgery.
If cancer is confirmed, doctors will perform
additional tests to determine whether the
cancer has spread within the breast, to the
lymph nodes or to other parts of the body.
The earliest form of breast cancer is called
ductal carcinoma in situ, and means that the
cancer cells are confined to the milk ducts in
the breast. This type of breast cancer is non-
invasive (meaning it has not spread to other
parts of the breast), and is the most curable
form of the disease.
If the breast cancer has spread beyond the
ducts and invaded other breast tissue, it is
called infiltrating ductal carcinoma. This is
the most common form of the disease,
account for nearly 80 percent of breast
cancers, according to Johns Hopkins School
of Medicine . This form of the disease could
eventually spread to the lymph nodes or
other parts of the body.
After diagnosis doctors also learn if the
tumor is caused by a genetic mutation
passed through families, or whether there are
hormone receptors on the breast cancer cells,
which indicate that the cancer may be
responsive to hormonal treatment.
No comments:
Post a Comment