Breast cancer hub
what is breast cancer?
Cancer that forms in the tissues of the breast. The most common type of breast cancer is ductal carcinoma, which begins in the lining of the milk ducts (thin tubes that carry milk from the lobules of the breast to the nipple). Another type of breast cancer is lobular carcinoma, which begins in the lobules (milk glands) of the breast. Invasive breast cancer is breast cancer that has spread from where it began in the breast ducts or lobules to surrounding normal tissue. Breast cancer occurs in both men and women, although male breast cancer is rare.
Different people have different symptoms of breast cancer. Some people do not have any signs or symptoms at all.
Some warning signs of breast cancer are:
New lump in the breast or underarm (armpit).
Thickening or swelling of part of the breast.
Irritation or dimpling of breast skin.
Redness or flaky skin in the nipple area or the breast.
Pulling in of the nipple or pain in the nipple area.
Nipple discharge other than breast milk, including blood.
Any change in the size or the shape of the breast.
Pain in any area of the breast.
Keep in mind that these symptoms can happen with other conditions that are not cancer.
If you have any signs or symptoms that worry you, be sure to see your doctor right away.
What is a normal breast?
No breast is typical. What is normal for you may not be normal for another woman. Most women say their breasts feel lumpy or uneven. The way your breasts look and feel can be affected by getting your period, having children, losing or gaining weight, and taking certain medications. Breasts also tend to change as you age. For more information, see the National Cancer Institute’s Breast Changes and Conditions.
What do lumps in my breast mean?
Many conditions can cause lumps in the breast, including cancer. But most breast lumps are caused by other medical conditions. The two most common causes of breast lumps are fibrocystic breast condition and cysts. Fibrocystic condition causes noncancerous changes in the breast that can make them lumpy, tender, and sore. Cysts are small fluid-filled sacs that can develop in the breast.
Doctors often use additional tests to find or diagnose breast cancer. They may refer women to a breast specialist or a surgeon. This does not mean that she has cancer or that she needs surgery. These doctors are experts in diagnosing breast problems.
Breast ultrasound. A machine that uses sound waves to make detailed pictures, called sonograms, of areas inside the breast.
Diagnostic mammogram. If you have a problem in your breast, such as lumps, or if an area of the breast looks abnormal on a screening mammogram, doctors may have you get a diagnostic mammogram. This is a more detailed X-ray of the breast.
Magnetic resonance imaging (MRI). A kind of body scan that uses a magnet linked to a computer. The MRI scan will make detailed pictures of areas inside the breast.
Biopsy. This is a test that removes tissue or fluid from the breast to be looked at under a microscope and do more testing. There are different kinds of biopsies (for example, fine-needle aspiration, core biopsy, or open biopsy).
Types of Breast Cancer by Location
Ductal breast cancer starts in the breast ducts—the parts of the breast where milk travels.
Lobular breast cancer starts in the lobes of the breast—the parts responsible for milk production.
Paget’s Disease starts in the nipple. It commonly comes with marked symptoms, including itching, burning and an eczema-like condition around the nipple, sometimes accompanied by oozing or bleeding.
Phyllodes tumors are rare tumors that occur in the stroma, or connective tissue, of the breast. These tumors are more common in premenopausal women and can be benign (not cancerous) or cancerous.
Inflammatory breast cancer occurs in the skin of the breast. Unlike other breast cancers, it frequently does not have a lump.
Types of Breast Cancer by Spread
In situ refers to cancer that has remained in the tissue where it started. All of the types of breast cancer listed above can stay in situ. Ductal carcinoma in situ (DCIS) remains in the ducts, for example. Lobular carcinoma in situ (LCIS) remains in the lobules.
Invasive cancers have moved out of breast ducts or lobules into nearby breast tissue. If in situ cancers begin to spread, doctors call them invasive. Once breast cancer has become invasive, it can move to other parts of the body, most commonly to the lymph nodes in the underarm (also called the axillary lymph nodes). The lymph nodes can provide an avenue for cancer to spread to other parts of the body.
Metastatic breast cancer refers to cancer that started in the breasts but has moved to other parts of the body, beyond the breast and surrounding lymph nodes. You might also hear this called stage IV, mets or advanced breast cancer, though “advanced” can also describe stage III cancers. Metastatic breast cancer can feel especially overwhelming, but know that many women live long, productive lives after this diagnosis.
Recurrent Breast Cancer
Breast cancer sometimes returns after treatment, even when it seemed to have disappeared. Doctors call this recurrent breast cancer. Recurrent breast cancer can remain in situ, or it can spread.
Local recurrence means breast cancer that returns to the same place it started.
Regional recurrence means breast cancer that returns after treatment and appears in other, nearby, parts of the body.
Distant recurrence means breast cancer that has returned and metastasized, meaning it has reappeared and spread to distant parts of the body. This can also be called metastatic or stage IV breast cancer.
Other types of breast cancer you may hear about include:
Colloid breast cancer, or mucinous breast cancer, a form of invasive ductal carcinoma that makes mucus and is typically less aggressive.
Medullary breast cancer, rare and resembling the color of brain tissue (the medulla) under the microscope. It is usually triple negative, more common in women with a BRCA mutation and less likely to involve the lymph nodes.
Tubular breast cancer, a type of invasive ductal carcinoma made up of tube-like structures. It tends to be small and slow-growing.
Receptor status and Triple Negative breast cancer
Your pathology report and your healthcare providers may describe your breast cancer as estrogen receptor (ER), progesterone receptor (PR) or human epidermal growth factor receptor-2 (HER2) positive or negative. Or, they may say that your breast cancer is triple negative or triple positive.
Estrogen and progesterone receptors (also called hormone receptors) are proteins found in some cancer cells that allow a hormone (estrogen, progesterone or both) to attach and “feed” the cancer cells. Hormone receptor status is reported as positive or negative and sometimes a percent is also provided. For example, 90% estrogen receptor positive. ER/PR+ breast cancers will, at a minimum, receive some form of hormone therapy such as Tamoxifen.
HER2 is a protein involved in normal cell growth, which may also be present on breast cancer cells. If too much of the HER2 protein is produced, the tumor is considered HER2+ (also called ERBB2). Breast cancers that are HER2+ will receive HER2 directed therapy such as Herceptin.
Triple positive breast cancer is positive for HER2, ER and PR. You will receive HER2 directed therapies as well as hormone therapy.
Triple negative breast cancer is negative for HER2, ER and PR. Therefore, HER2 directed therapy and hormone therapy are not utilized. Typical treatment is chemotherapy.
Preliminary information about your cancer’s type will come from a biopsy and imaging tests such as ultrasounds, mammograms and MRIs. More specific answers can come from your pathology report. Your doctor will also describe your cancer in more detail when you discuss breast cancer stages.
If breast cancer is diagnosed, other tests are done to find out if cancer cells have spread within the breast or to other parts of the body. This process is called staging. Whether the cancer is only in the breast, is found in lymph nodes under your arm, or has spread outside the breast determines your stage of breast cancer. The type and stage of breast cancer tells doctors what kind of treatment you need. For more information, visit Stages of Breast Cancer.
The pathologic stage (also called the surgical stage) is determined by examining tissue removed during an operation.
Sometimes, if surgery is not possible right away or at all, the cancer will be given a clinical stage instead. This is based on the results of a physical exam, biopsy, and imaging tests. The clinical stage is used to help plan treatment. Sometimes, though, the cancer has spread further than the clinical stage estimates, and may not predict the patient’s outlook as accurately as a pathologic stage.
In both staging systems, 7 key pieces of information are used:
The extent (size) of the tumor (T): How large is the cancer? Has it grown into nearby areas?
The spread to nearby lymph nodes (N): Has the cancer spread to nearby lymph nodes? If so, how many?
The spread (metastasis) to distant sites (M): Has the cancer spread to distant organs such as the lungs or liver?
Estrogen Receptor (ER) status: Does the cancer have the protein called an estrogen receptor?
Progesterone Receptor (PR) status: Does the cancer have the protein called a progesterone receptor?
Her2 status: Does the cancer make too much of a protein called Her2?
Grade of the cancer (G): How much do the cancer cells look like normal cells?
In addition, Oncotype Dx® Recurrence Score results may also be considered in the stage in certain circumstances.
Once all of these factors have been determined, this information is combined in a process called stage grouping to assign an overall stage. For more information see Cancer Staging.
Details about the first three factors (the TNM categories) are below. However, the addition of information about ER, PR, and Her2 status along with grade has made stage grouping for breast cancer more complex than for other cancers. Because of this, it is best to ask your doctor about your specific stage and what it means.
Details of the TNM staging system
Numbers or letters after T, N, and M provide more details about each of these factors. Higher numbers mean the cancer is more advanced.
T categories for breast cancer
T followed by a number from 0 to 4 describes the main (primary) tumor's size and if it has spread to the skin or to the chest wall under the breast. Higher T numbers mean a larger tumor and/or wider spread to tissues near the breast.
TX: Primary tumor cannot be assessed.
T0: No evidence of primary tumor.
Tis: Carcinoma in situ (DCIS, or Paget disease of the breast with no associated tumor mass)
T1 (includes T1a, T1b, and T1c): Tumor is 2 cm (3/4 of an inch) or less across.
T2: Tumor is more than 2 cm but not more than 5 cm (2 inches) across.
T3: Tumor is more than 5 cm across.
T4 (includes T4a, T4b, T4c, and T4d): Tumor of any size growing into the chest wall or skin. This includes inflammatory breast cancer.
N categories for breast cancer
N followed by a number from 0 to 3 indicates whether the cancer has spread to lymph nodes near the breast and, if so, how many lymph nodes are involved.
Lymph node staging for breast cancer is based on how the nodes look under the microscope, and has changed as technology has improved. Newer methods have made it possible to find smaller and smaller collections of cancer cells, but experts haven't been sure how much these tiny deposits of cancer cells affect outlook.
It’s not yet clear how much cancer in the lymph node is needed to see a change in outlook or treatment. This is still being studied, but for now, a deposit of cancer cells must contain at least 200 cells or be at least 0.2 mm across (less than 1/100 of an inch) for it to change the N stage. An area of cancer spread that is smaller than 0.2 mm (or fewer than 200 cells) doesn't change the stage, but is recorded with abbreviations (i+ or mol+) that indicate the type of special test used to find the spread.
If the area of cancer spread is at least 0.2 mm (or 200 cells), but still not larger than 2 mm, it is called a micrometastasis (one mm is about the size of the width of a grain of rice). Micrometastases are counted only if there aren't any larger areas of cancer spread. Areas of cancer spread larger than 2 mm are known to affect outlook and do change the N stage. These larger areas are sometimes called macrometastases, but are more often just called metastases.
NX: Nearby lymph nodes cannot be assessed (for example, if they were removed previously).
N0: Cancer has not spread to nearby lymph nodes.
N0(i+): The area of cancer spread contains fewer than 200 cells and is smaller than 0.2 mm. The abbreviation "i+" means that a small number of cancer cells (called isolated tumor cells) were seen in routine stains or when a special type of staining technique, called immunohistochemistry, was used.
N0(mol+): Cancer cells cannot be seen in underarm lymph nodes (even using special stains), but traces of cancer cells were detected using a technique called RT-PCR. RT-PCR is a molecular test that can find very small numbers of cancer cells. (This test is not often used to find breast cancer cells in lymph nodes because the results do not influence treatment decisions.)
N1: Cancer has spread to 1 to 3 axillary (underarm) lymph node(s), and/or tiny amounts of cancer are found in internal mammary lymph nodes (those near the breast bone) on sentinel lymph node biopsy.
N1mi: Micrometastases (tiny areas of cancer spread) in the lymph nodes under the arm. The areas of cancer spread in the lymph nodes are at least 0.2mm across, but not larger than 2mm.
N1a: Cancer has spread to 1 to 3 lymph nodes under the arm with at least one area of cancer spread greater than 2 mm across.
N1b: Cancer has spread to internal mammary lymph nodes on the same side as the cancer, but this spread could only be found on sentinel lymph node biopsy (it did not cause the lymph nodes to become enlarged).
N1c: Both N1a and N1b apply.
N2: Cancer has spread to 4 to 9 lymph nodes under the arm, or cancer has enlarged the internal mammary lymph nodes
N2a: Cancer has spread to 4 to 9 lymph nodes under the arm, with at least one area of cancer spread larger than 2 mm.
N2b: Cancer has spread to one or more internal mammary lymph nodes, causing them to become enlarged.
N3: Any of the following:
Cancer has spread to 10 or more axillary lymph nodes, with at least one area of cancer spread greater than 2 mm,
Cancer has spread to the lymph nodes under the collarbone (infraclavicular nodes), with at least one area of cancer spread greater than 2 mm.
Cancer is found in at least one axillary lymph node (with at least one area of cancer spread greater than 2 mm) and has enlarged the internal mammary lymph nodes,
Cancer has spread to 4 or more axillary lymph nodes (with at least one area of cancer spread greater than 2 mm), and tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy.
N3c: Cancer has spread to the lymph nodes above the collarbone (supraclavicular nodes) with at least one area of cancer spread greater than 2 mm.
M categories for breast cancer
M followed by a 0 or 1 indicates whether the cancer has spread to distant organs -- for example, the lungs, liver, or bones.
MX: Distant spread (metastasis) cannot be assessed.
M0: No distant spread is found on x-rays (or other imaging tests) or by physical exam.
cM0(i+): Small numbers of cancer cells are found in blood or bone marrow (found only by special tests), or tiny areas of cancer spread (no larger than 0.2 mm) are found in lymph nodes away from the underarm, collarbone, or internal mammary areas.
M1: Cancer has spread to distant organs (most often to the bones, lungs, brain, or liver).
After puberty, a woman’s breast consists of fat, connective tissue, and thousands of lobules. These are tiny glands that produce milk for breastfeeding. Tiny tubes, or ducts, carry the milk toward the nipple.
Cancer causes the cells to multiply uncontrollably. They do not die at the usual point in their life cycle. This excessive cell growth causes cancer because the tumor uses nutrients and energy and deprives the cells around it.
Breast cancer usually starts in the inner lining of milk ducts or the lobules that supply them with milk. From there, it can spread to other parts of the body.
Studies have shown that your risk for breast cancer is due to a combination of factors. The main factors that influence your risk include being a woman and getting older. Most breast cancers are found in women who are 50 years old or older.
Some women will get breast cancer even without any other risk factors that they know of. Having a risk factor does not mean you will get the disease, and not all risk factors have the same effect. Most women have some risk factors, but most women do not get breast cancer. If you have breast cancer risk factors, talk with your doctor about ways you can lower your risk and about screening for breast cancer.
Risk factors you cannot change:
Getting older. The risk for breast cancer increases with age; most breast cancers are diagnosed after age 50.
Genetic mutations. Inherited changes (mutations) to certain genes, such as BRCA1 and BRCA2. Women who have inherited these genetic changes are at higher risk of breast and ovarian cancer.
Reproductive history. Early menstrual periods before age 12 and starting menopause after age 55 expose women to hormones longer, raising their risk of getting breast cancer.
Having dense breasts. Dense breasts have more connective tissue than fatty tissue, which can sometimes make it hard to see tumors on a mammogram. Women with dense breasts are more likely to get breast cancer.
Personal history of breast cancer or certain non-cancerous breast diseases. Women who have had breast cancer are more likely to get breast cancer a second time. Some non-cancerous breast diseases such as atypical hyperplasia or lobular carcinoma in situ are associated with a higher risk of getting breast cancer.
Family history of breast cancer. A woman’s risk for breast cancer is higher if she has a mother, sister, or daughter (first-degree relative) or multiple family members on either her mother’s or father’s side of the family who have had breast cancer. Having a first-degree male relative with breast cancer also raises a woman’s risk.
Previous treatment using radiation therapy. Women who had radiation therapy to the chest or breasts (like for treatment of Hodgkin’s lymphoma) before age 30 have a higher risk of getting breast cancer later in life.
Women who took the drug diethylstilbestrol (DES), which was given to some pregnant women in the United States between 1940 and 1971 to prevent miscarriage, have a higher risk. Women whose mothers took DES while pregnant with them are also at risk.
Risk factors you can change:
Not being physically active. Women who are not physically active have a higher risk of getting breast cancer.
Being overweight or obese after menopause. Older women who are overweight or obese have a higher risk of getting breast cancer than those at a normal weight.
Taking hormones. Some forms of hormone replacement therapy (those that include both estrogen and progesterone) taken during menopause can raise risk for breast cancer when taken for more than five years. Certain oral contraceptives (birth control pills) also have been found to raise breast cancer risk.
Reproductive history. Having the first pregnancy after age 30, not breastfeeding, and never having a full-term pregnancy can raise breast cancer risk.
Drinking alcohol. Studies show that a woman’s risk for breast cancer increases with the more alcohol she drinks.
Research suggests that other factors such as smoking, being exposed to chemicals that can cause cancer, and changes in other hormones due to night shift working also may increase breast cancer risk.
Your doctor determines your breast cancer treatment options based on your type of breast cancer, its stage and grade, size, and whether the cancer cells are sensitive to hormones. Your doctor also considers your overall health and your own preferences.
Most women undergo surgery for breast cancer and many also receive additional treatment after surgery, such as chemotherapy, hormone therapy or radiation. Chemotherapy might also be used before surgery in certain situations.
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
A person who has undergone a total (simple) mastectomy without breast reconstruction
Sentinel node biopsy
Sentinel node biopsy
Radiation therapy for breast cancer
Operations used to treat breast cancer include:
Removing the breast cancer (lumpectomy). During a lumpectomy, which may be referred to as breast-conserving surgery or wide local excision, the surgeon removes the tumor and a small margin of surrounding healthy tissue.
A lumpectomy may be recommended for removing smaller tumors. Some people with larger tumors may undergo chemotherapy before surgery to shrink a tumor and make it possible to remove completely with a lumpectomy procedure.
Removing the entire breast (mastectomy). A mastectomy is an operation to remove all of your breast tissue. Most mastectomy procedures remove all of the breast tissue — the lobules, ducts, fatty tissue and some skin, including the nipple and areola (total or simple mastectomy).
Newer surgical techniques may be an option in selected cases in order to improve the appearance of the breast. Skin-sparing mastectomy and nipple-sparing mastectomy are increasingly common operations for breast cancer.
Removing a limited number of lymph nodes (sentinel node biopsy). To determine whether cancer has spread to your lymph nodes, your surgeon will discuss with you the role of removing the lymph nodes that are the first to receive the lymph drainage from your tumor.
If no cancer is found in those lymph nodes, the chance of finding cancer in any of the remaining lymph nodes is small and no other nodes need to be removed.
Removing several lymph nodes (axillary lymph node dissection). If cancer is found in the sentinel lymph nodes, your surgeon will discuss with you the role of removing additional lymph nodes in your armpit.
Removing both breasts. Some women with cancer in one breast may choose to have their other (healthy) breast removed (contralateral prophylactic mastectomy) if they have a very increased risk of cancer in the other breast because of a genetic predisposition or strong family history.
Most women with breast cancer in one breast will never develop cancer in the other breast. Discuss your breast cancer risk with your doctor, along with the benefits and risks of this procedure.
Complications of breast cancer surgery depend on the procedures you choose. Breast cancer surgery carries a risk of pain, bleeding, infection and arm swelling (lymphedema).
You may 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 breast implant (silicone or water) or reconstruction using your own tissue. These operations can be performed at the time of your mastectomy or at a later date.
Radiation therapy uses high-powered beams of energy, such as X-rays and protons, 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 of the whole breast is commonly used after a lumpectomy. Breast brachytherapy may be an option after a lumpectomy if you have a low risk of cancer recurrence.
Doctors may also recommend radiation therapy to the chest wall after a mastectomy for larger breast cancers or cancers that have spread to the lymph nodes.
Breast cancer radiation can last from three days to six weeks, depending on the treatment. A doctor who uses radiation to treat cancer (radiation oncologist) determines which treatment is best for you based on your situation, your cancer type and the location of your tumor.
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, such as damage to the heart or lungs or, very rarely, second cancers in the treated area.
Chemotherapy uses drugs to destroy fast-growing cells, such as cancer cells. If your cancer has a high risk 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.
Chemotherapy is sometimes given before surgery in women with larger breast tumors. The goal is to shrink a tumor to a size that makes it easier to remove with surgery.
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, fatigue and an increased risk of developing an infection. Rare side effects can include premature menopause, infertility (if premenopausal), damage to the heart and kidneys, nerve damage, and, very rarely, blood cell cancer.
Hormone therapy — perhaps more properly termed hormone-blocking therapy — is used to treat breast cancers that are sensitive to hormones. Doctors refer to these cancers as estrogen receptor positive (ER positive) and progesterone receptor positive (PR positive) cancers.
Hormone therapy can be used before or 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:
Medications that block hormones from attaching to cancer cells (selective estrogen receptor modulators)
Medications that stop the body from making estrogen after menopause (aromatase inhibitors)
Surgery or medications to stop hormone production in the ovaries
Hormone therapy side effects depend on your specific treatment, but may include hot flashes, night sweats and vaginal dryness. More serious side effects include a risk of bone thinning and blood clots.
Targeted therapy drugs
Targeted drug treatments attack specific abnormalities within cancer cells. As an example, several targeted therapy drugs focus on a protein that some breast cancer cells overproduce called human epidermal growth factor receptor 2 (HER2). The protein helps breast cancer cells grow and survive. By targeting cells that make too much HER2, the drugs can damage cancer cells while sparing healthy cells.
Targeted therapy drugs that focus on other abnormalities within cancer cells are available. And targeted therapy is an active area of cancer research.
Your cancer cells may be tested to see whether you might benefit from targeted therapy drugs. Some medications are used after surgery to reduce the risk that the cancer will return. Others are used in cases of advanced breast cancer to slow the growth of the tumor.
Immunotherapy uses your immune system to fight cancer. Your body's disease-fighting immune system may not attack your cancer because the cancer cells produce proteins that blind the immune system cells. Immunotherapy works by interfering with that process.
Immunotherapy might be an option if you have triple-negative breast cancer, which means that the cancer cells don't have receptors for estrogen, progesterone or HER2. For triple-negative breast cancer, immunotherapy is combined with chemotherapy to treat advanced cancer that's spread to other parts of the body.
Supportive (Palliative) Care
Palliative care is specialized medical care that focuses on providing relief from pain and other symptoms of a serious illness. Palliative care specialists work with you, your family and your other doctors to provide an extra layer of support that complements your ongoing care. Palliative care can be used while undergoing other aggressive treatments, such as surgery, chemotherapy or radiation therapy.
When palliative care is used along with all of the other appropriate treatments, people with cancer may feel better and live longer.
Palliative care is provided by a team of doctors, nurses and other specially trained professionals. Palliative care teams aim to improve the quality of life for people with cancer and their families. This form of care is offered alongside curative or other treatments you may be receiving.
Professor Dorothy Roberts, JD discusses a 2007 study indicating that black women in Chicago had a lower rate of breast cancer than white women, but a higher death rate from the disease.
In 1980, the death rate of both Chicago groups was the same, but diverged dramatically over the next two decades. Black women's death rate didn't increase; it was white women's death rate that decreased by 50% over that period.
The conclusion is that inequity in access to diagnosis and treatment resulted in the survival disparity between these groups of women.