Filed under: Cancer & Chemo
Breast cancer is cancer that forms in the cells of the breasts. Breast cancer can occur in both men and women, but it's far more common in women.
After skin cancer, breast cancer is the most common cancer diagnosed in women in the United States. But breast cancer rates have fallen in recent years, though doctors aren't certain why. Still, for many women, breast cancer is the disease they fear most.
Public support for breast cancer awareness and research funding has helped improve the diagnosis and treatment of breast cancer. Breast cancer survival rates have increased and the number of deaths has been declining, thanks to earlier detection, new treatments and a better understanding of the disease.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Signs and symptoms of breast cancer may include:
When to see a doctor
If you find a lump or other change in your breast — even if a recent mammogram was normal — make an appointment with your doctor.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
It's not clear what causes breast cancer. Doctors know that breast cancer occurs when some breast cells begin growing abnormally. These cells divide more rapidly than healthy cells do. The accumulating cells form a tumor that may spread (metastasize) through your breast, to your lymph nodes or to other parts of your body.
Breast cancer most often begins with cells in the milk-producing ducts. Doctors call this type of breast cancer invasive ductal carcinoma. Breast cancer may also begin in the lobules (invasive lobular carcinoma) or cells within the breast.
Researchers have identified things that can increase your risk of breast cancer. But it's not clear why some people who have no risk factors develop cancer, yet other people with risk factors never do. It's likely that breast cancer is caused by a complex combination of your genetic makeup and your environment.
Inherited breast cancer
Doctors estimate that 5 to 10 percent of breast cancers are linked to gene mutation passed through generations of a family. A number of inherited defective genes that can increase the likelihood of breast cancer have been identified. The most common are breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2), both of which increase the risk of both breast and ovarian cancer.
If you have a strong family history of breast cancer or other cancers, blood tests may help identify defective BRCA or other genes that are being passed through your family. Consider asking your doctor for a referral to a genetic counselor who can review your family health history. A genetic counselor can also discuss the benefits, risks and limitations of genetic testing with you.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
A risk factor is anything that makes it more likely you'll get a particular disease. But having one or even several risk factors doesn't necessarily mean you'll develop cancer — most women with breast cancer have no known risk factors other than simply being women.
Things that can increase your risk of breast cancer include:
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Consulting with your health care team
Women with breast cancer may have appointments with their primary care doctors, as well as several other doctors and other health professionals, including:
What you can do to prepare
Questions to ask your doctor
Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out. For breast cancer, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Diagnosing breast cancer
Tests and procedures used to diagnose breast cancer include:
Other tests and procedures may be used depending on your situation.
Staging breast cancer
Once your doctor has diagnosed your breast cancer, he or she works to determine the extent (stage) of your cancer. Your cancer's stage helps determine your prognosis and your treatment options. Complete information about your cancer's stage may not be available until after you undergo breast cancer surgery.
Tests and procedures used to stage breast cancer may include:
Not all women will need all of these tests and procedures. Your doctor selects the appropriate tests.
Breast cancer stages range from 0 to IV, with 0 indicating cancer that is very small and noninvasive. Stage IV breast cancer, also called metastatic breast cancer, indicates cancer that has spread to other areas of the body.
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Your doctor determines your breast cancer treatment options based on your type of breast cancer, its stage, whether the cancer cells are sensitive to hormones, your overall health and your own preferences. Most women undergo surgery for breast cancer and also receive additional treatment, such as chemotherapy, hormone therapy or radiation.
There are many options for breast cancer treatment and you may feel overwhelmed as you make complex decisions about your treatment. Consider seeking a second opinion from a breast specialist in a breast center or clinic. Talk to other women who have faced the same decision.
Breast cancer surgery
Operations used to treat breast cancer include:
Complications of breast cancer surgery depend on the procedures you choose. Surgery carries a risk of bleeding and infection. Surgery to remove your lymph nodes increases your risk of arm swelling (lymphedema).
Some women choose to have breast reconstruction after surgery. Discuss your options and preferences with your surgeon. Consider a referral to a plastic surgeon before your breast cancer surgery. Your options may include reconstruction with a synthetic breast implant or reconstruction using your own tissue. These operations can be performed at the time of your mastectomy or at a later date.
Radiation therapy
Radiation therapy uses high-powered beams of energy, such as X-rays, to kill cancer cells. Radiation therapy is typically done using a large machine that aims the energy beams at your body (external beam radiation). But radiation can also be done by placing radioactive material inside your body (brachytherapy).
External beam radiation is commonly used after lumpectomy for early-stage breast cancer. Doctors may also recommend radiation therapy after mastectomy for larger breast cancers.
Side effects of radiation therapy include fatigue and a red, sunburn-like rash where the radiation is aimed. Breast tissue may also appear swollen or more firm. Rarely, more serious problems may occur, including arm swelling (lymphedema), broken ribs and damage to the lungs or nerves.
Chemotherapy
Chemotherapy uses drugs to destroy cancer cells. If your cancer has a high chance of returning or spreading to another part of your body, your doctor may recommend chemotherapy after surgery to decrease the chance that the cancer will recur. This is known as adjuvant systemic chemotherapy.
Chemotherapy is sometimes given before surgery in women with larger breast tumors. Doctors call this neoadjuvant chemotherapy. The goal is to shrink a tumor to a size that makes it easier to remove with surgery. This may also increase the chance of a cure. Research is ongoing into neoadjuvant chemotherapy to determine who may benefit from this treatment.
Chemotherapy is also used in women whose cancer has already spread to other parts of the body. Chemotherapy may be recommended to try to control the cancer and decrease any symptoms the cancer is causing.
Chemotherapy side effects depend on the drugs you receive. Common side effects include hair loss, nausea, vomiting, fever and frequent infections.
Hormone therapy
Hormone therapy — perhaps more properly termed hormone blocking therapy — is often used to treat breast cancers that are sensitive to hormones. Doctors sometimes refer to these cancers as estrogen and progesterone receptor positive cancers.
Hormone therapy can be used after surgery or other treatments to decrease the chance of your cancer returning. If the cancer has already spread, hormone therapy may shrink and control it.
Treatments that can be used in hormone therapy include:
Side effects of hormone therapy vary according to which medication you receive, but typically include menopausal symptoms, such as hot flashes, vaginal dryness, decreased sex drive and mood changes. Side effects of aromatase inhibitors include joint and muscle pain, as well as an increased risk of bone thinning (osteoporosis).
Targeted drugs
Targeted drug treatments attack specific abnormalities within cancer cells. Targeted drugs approved to treat breast cancer include:
Side effects of targeted drugs depend on the drug you receive. Targeted drugs can be very expensive and aren't always covered by health insurance.
Clinical trials
Clinical trials are used to test new and promising agents in the treatment of cancer. Clinical trials represent the cutting edge of cancer treatment, but they're often unproven treatments that may or may not be superior to currently available therapies. Talk with your doctor about clinical trials to see if one is right for you.
Examples of treatments being studied in breast cancer clinical trials include:
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No alternative medicine treatments have been found to cure breast cancer. But complementary and alternative medicine therapies may help you cope with side effects of treatment when combined with your doctor's care.
Alternative medicine for fatigue
Many breast cancer survivors experience fatigue during and after treatment that can continue for years. Doctors aren't sure what causes cancer-related fatigue and it can persist despite treatment. When combined with your doctor's care, complementary and alternative medicine therapies may help relieve fatigue. Ask your doctor about:
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
A breast cancer diagnosis can be overwhelming. And just when you're trying to cope with the shock and the fears about your future, you're asked to make important decisions about your treatment.
Every woman finds her own way of coping with a breast cancer diagnosis. Until you find what works for you, it might help to:
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.
Breast cancer prevention for women with an average risk
Making changes in your daily life may help reduce your risk of breast cancer. Try to:
Breast cancer prevention for women with a high risk
If your doctor has assessed your family history and other factors and determined that you may have an increased risk of breast cancer, options to reduce your risk include:
©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

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