Breast Cancer
Breast cancer is when breast cells mutate and become cancerous cells that multiply and form
tumors. Breast cancer typically affects women and people assigned female at birth (AFAB) age
50 and older, but it can also affect men and people assigned male at birth (AMAB), as well as
younger women. Healthcare providers may treat breast cancer with surgery to remove tumors or
treatment to kill cancerous cells.
ContentsOverviewSymptoms and CausesDiagnosis and TestsManagement and
TreatmentPreventionOutlook / PrognosisLiving WithAdditional Common Questions
ContentsOverviewSymptoms and CausesDiagnosis and TestsManagement and
TreatmentPreventionOutlook / PrognosisLiving WithAdditional Common Questions
Overview
Breast cancer tumors develop when breast cells mutate and grow.
What is breast cancer?
Breast cancer is one of the most common cancers that affects women and people
assigned female at birth (AFAB). It happens when cancerous cells in
your breasts multiply and become tumors. About 80% of breast cancer cases are
invasive, meaning a tumor may spread from your breast to other areas of your body.
Breast cancer typically affects women age 50 and older, but it can also affect women
and people AFAB who are younger than 50. Men and people assigned male at birth
(AMAB) may also develop breast cancer.
Breast cancer types
Healthcare providers determine cancer types and subtypes so they can tailor treatment
to be as effective as possible with the fewest possible side effects. Common types of
breast cancer include:
Invasive (infiltrating) ductal carcinoma (IDC) : This cancer starts in your milk
ducts and spreads to nearby breast tissue. It’s the most common type of breast
cancer in the United States.
Lobular breast cancer : This breast cancer starts in the milk-producing glands
(lobules) in your breast and often spreads to nearby breast tissue. It’s the second
most common breast cancer in the United States.
Ductal carcinoma in situ (DCIS) : Like IDC, this breast cancer starts in your milk
ducts. The difference is DCIS doesn’t spread beyond your milk ducts.
Less common breast cancer types include:
Triple-negative breast cancer (TNBC) : This invasive cancer is aggressive and
spreads more quickly than other breast cancers.
Inflammatory breast cancer (IBC) : This rare, fast-growing cancer looks like a
rash on your breast. IBC is rare in the United States.
Paget’s disease of the breast : This rare cancer affects the skin of your nipple
and may look like a rash. Less than 4% of all breast cancers are Paget’s disease
of the breast.
Breast cancer subtypes
Healthcare providers classify breast cancer subtypes by receptor cell status. Receptors
are protein molecules in or on cells’ surfaces. They can attract or attach to certain
substances in your blood, including hormones like estrogen and
progesterone. Estrogen and progesterone help cancerous cells to grow. Finding out if
cancerous cells have estrogen or progesterone receptors helps healthcare providers
plan breast cancer treatment.
Subtypes include:
ER-positive (ER+) breast cancers have estrogen receptors.
PR-positive (PR+) breast cancers have progesterone receptors.
HR-positive (HR+) breast cancers have estrogen and progesterone receptors.
HR-negative (HR-) breast cancers don’t have estrogen or progesterone
receptors.
HER2-positive (HER2+) breast cancers, which have higher than normal levels of
the HER2 protein. This protein helps cancer cells to grow. About 15% to 20% of
all breast cancers are HER2-positive.
Symptoms and Causes
Common signs of breast cancer and what to look for.
What are breast cancer symptoms?
The condition can affect your breasts in different ways. Some breast cancer symptoms
are very distinctive. Others may simply seem like areas of your breast that look very
different from any other area. Breast cancer may not cause noticeable symptoms either.
But when it does, symptoms may include:
A change in the size, shape or contour of your breast.
A mass or lump, which may feel as small as a pea.
A lump or thickening in or near your breast or in your underarm that persists
through your menstrual cycle.
A change in the look or feel of your skin on your breast or nipple. Your skin may
look dimpled, puckered, scaly or inflamed. It may look red, purple or darker than
other parts of your breast.
A marble-like hardened area under your skin.
A blood-stained or clear fluid discharge from your nipple.
What causes breast cancer?
Experts know breast cancer happens when breast cells mutate and become cancerous
cells that divide and multiply to create tumors. They aren’t sure what triggers that
change. However, research shows there are several risk factors that may increase your
chances of developing breast cancer. These include:
Age: Being 55 or older.
Sex: Women and people AFAB are much more likely to develop the condition
than men and people AMAB.
Family history: If your parents, siblings, children or other close relatives have
breast cancer, you’re at risk of developing the disease.
Genetics: Up to 15% of people with breast cancer develop the disease because
they have inherited genetic mutations. The most common genetic mutations
involve the BRCA1 and BRCA2 genes.
Smoking: Tobacco use has been linked to many different types of cancer,
including breast cancer.
Drinking beverages containing alcohol: Research shows that drinking
beverages containing alcohol may increase breast cancer risk.
Having obesity.
Radiation exposure: If you’ve had prior radiation therapy — especially to your
head, neck or chest — you’re more likely to develop breast cancer.
Hormone replacement therapy: People who use hormone replacement
therapy (HRT) have a higher risk of being diagnosed with the condition.
What are the complications of breast cancer?
The most significant complication is metastatic breast cancer — breast cancer that
spreads to other areas of your body, including your brain, bones, liver and lungs.
Studies show about 1 in 3 women and people AFAB who have early-stage cancer later
develop metastatic breast cancer.
Diagnosis and Tests
How is breast cancer diagnosed?
Healthcare providers may do physical examinations or order mammograms to check for
signs of breast cancer. But they do the following tests to diagnose the disease:
Breast ultrasound.
Breast magnetic resonance imaging (MRI) scan.
Breast biopsy.
Immunohistochemistry test to check for hormone receptors.
Genetic tests to identify mutations that cause breast cancer.
Stages of breast cancer
Healthcare providers use cancer staging systems to plan treatment. Staging cancer
also helps providers set a prognosis, or what you can expect after treatment. Breast
cancer staging depends on factors like breast cancer type, tumor size and location, and
whether cancer has spread to other areas of your body. Breast cancer stages are:
Stage 0: The disease is noninvasive, meaning it hasn’t spread from your breast
ducts to other parts of your breast.
Stage I: There are cancerous cells in nearby breast tissue.
Stage II: The cancerous cells have formed a tumor or tumors. The tumor is either
smaller than 2 centimeters across and has spread to underarm lymph nodes or
larger than 5 centimeters across but hasn’t spread to underarm lymph nodes.
Tumors at this stage can measure anywhere between 2 and 5 centimeters
across, and may or may not affect the nearby lymph nodes.
Stage III: There’s breast cancer in nearby tissue and lymph nodes. Stage III is
usually referred to as locally advanced breast cancer.
Stage IV: Cancer has spread from your breast to areas like your
bones, liver, lungs or brain.
Management and Treatment
How is breast cancer treated?
Surgery is the primary breast cancer treatment, but healthcare providers may use other
treatments. Breast cancer surgeries include:
Mastectomy.
Lumpectomy.
Breast reconstruction.
Providers may combine surgery with one or more of the following treatments:
Chemotherapy.
Radiation therapy, including intraoperative radiation therapy (IORT).
Immunotherapy.
Hormone therapy, including selective estrogen receptor modulator (SERM)
therapy.
Targeted therapy.
What are treatment side effects?
Common chemotherapy and radiation therapy side effects include fatigue, nausea and
vomiting. Targeted therapy, immunotherapy and hormone therapy have similar side
effects, including gastrointestinal issues like constipation and diarrhea.
People react differently to breast cancer treatments. If you’re receiving treatment, ask
your healthcare provider how treatment may affect you, including how it may affect your
daily life. Also, ask your provider about palliative care. Palliative care helps manage
breast cancer symptoms and treatment side effects so you’re as comfortable as
possible as you go through treatment.
Complications of breast cancer surgery
All surgeries have potential complications, and breast cancer surgery is no exception.
As you’re considering your options, it’s important to remember that surgery removes
potentially life-threatening cancer. In general, the risks of breast cancer outweigh the
complications.
If you’re having breast cancer surgery, ask your healthcare provider to explain potential
complications, which may include:
Infection at the surgical site.
Blood clots that can happen after surgery.
Nerve damage.
Lymphedema.
Prevention
Can breast cancer be prevented?
You may not be able to prevent breast cancer. But you can reduce your risk of
developing it. Just as important, regular self-exams and mammograms can help detect
breast cancer early on, when it’s easier to treat.
How can I lower my risk?
There’s no sure way to reduce breast cancer risk, but the American Cancer Society
(ACS) has the following advice for all women and people AFAB:
Get to and stay at a healthy weight: This is a weight that’s right for you. Ask a
healthcare provider for information on setting up healthy weight management.
Eat a healthy diet: Some studies show a diet that includes vegetables, fruit,
calcium-rich dairy foods and lean protein may reduce your risk of breast cancer.
Avoiding red meat and processed meat may also reduce your risk.
Get moving: Studies show that regular physical activity lowers breast cancer
risk.
Avoid beverages containing alcohol: Research shows a link between breast
cancer and alcohol. The American Medical Association recommends women and
people AFAB limit alcohol to one drink a day.
Get screened: Mammograms often detect tumors when they’re too small to be
felt.
Do regular self-exams: Examining your breasts regularly helps to maintain
breast health and may allow you to find breast cancer tumors.
Some women and people AFAB have an increased risk for breast cancer because
family members have it or they inherited a genetic mutation. If that’s your situation, you
may want to consider the following:
Genetic screening for breast cancer genes.
Medication that may lower breast cancer risk
like tamoxifen, raloxifene or aromatase inhibitors.
Prophylactic (preventive) mastectomy .
Frequent breast cancer screenings and physical examinations. If you have an
increased risk for breast cancer, ask your provider if you should have additional
tests to detect breast cancer, particularly if you’re under age 40 and have
increased risk.
Outlook / Prognosis
What is the survival rate for breast cancer?
Breast cancer survival rates vary based on several factors, like whether the cancer is
invasive or noninvasive, the cancer type and the cancer stage. According to data kept
by the National Cancer Institute (U.S.), overall, 91% of people with breast cancer were
alive five years after diagnosis. The institute organizes breast cancer survival rates by
stages:
Local: Cancer hasn’t spread outside your breast.
Regional: Cancer has spread to nearby lymph nodes and tissue.
Distant: Cancer is in more distant areas of your body like your liver or lungs.
Breast cancer stage Five-year survival rate
Local 99%
Regional 86%
Distant 30%
As you think about breast cancer survival rates, remember, they’re only estimates
based on other people’s experiences. Cancer affects different people in different ways.
If you have specific questions about cancer survival rates, talk to your healthcare
provider. They’re your best resource because they know your situation.
What’s the outlook for breast cancer?
Right now, more people are being diagnosed with early-stage breast cancer — meaning
they’re diagnosed when it’s easier to treat — and fewer people are dying of breast
cancer.
Data shows 99% of people with early-stage breast cancer were alive five years after
diagnosis. In some cases, they may be considered cured of breast cancer. But breast
cancer can come back, and when it does, it may come back as metastatic breast
cancer.
Outlook may also depend on race. According to the American Cancer Society, Black
women and people AFAB are slightly less likely to develop breast cancer than white
women. But Black women are more likely to die of breast cancer than white women.
Living With
How do I take care of myself?
Living with breast cancer may not be easy. You may have days when you feel
overwhelmed by your situation. Consider the following suggestions for taking care of
yourself as you go through breast cancer diagnosis and treatment:
Get enough rest: Breast cancer and treatment can be exhausting. Try to
remember to rest when you need to, not just when you think you have time.
Eat well: Treatment may affect your appetite. A diet of fruit, vegetables, lean
protein and healthy grains can help you stay strong during treatment.
Manage your stress: Cancer is stressful. Exercise can help, from regular walks
to exercise programs.
Find support: You’re a breast cancer survivor, starting the day you were
diagnosed. Ask your healthcare provider about cancer survivorship programs,
which may help you manage some of the challenges that come with living with
breast cancer.
