Breast Cancer Facts & Risk Factors & Types
What is it?How many women get it?Risk FactorsAgeFamily historyNO Family HistoryPersonal History of Breast CancerRaceAnatomy
- Breast cancer is a malignant (cancerous) tumor that starts from cells of the breast. The disease occurs mostly in women, but men can get breast cancer as well.
- About 232,340 women in the U.S. will be diagnosed with invasive breast cancer this year.
- Currently, there are more than 2 million women living in the U.S. who have been treated for breast cancer.
- The chance of a woman having invasive breast cancer some time during her life is about one in seven.
- About 1 in 8 U.S. women (just under 12%) will develop invasive breast cancer over the course of her lifetime.
- It is about 100 times more common in women than in men.
- In 2011, an estimated 230,480 new cases of invasive breast cancer were expected to be diagnosed in women in the U.S., along with 57,650 new cases of non-invasive (in situ) breast cancer.
- Besides skin cancer, breast cancer is the most commonly diagnosed cancer among American women. Just under 30% of cancers in women are breast cancers.
- White women are slightly more likely to develop breast cancer than African-American women. However, in women under 45, breast cancer is more common in African-American women than white women.
- In 2011, there were more than 2.6 million breast cancer survivors in the US.
- A woman’s risk of breast cancer approximately doubles if she has a first-degree relative (mother, sister, daughter) who has been diagnosed with breast cancer. About 15% of women who get breast cancer have a family member diagnosed with it.
- The most significant risk factors for breast cancer are gender (being a woman) and age (growing older).
- Nearly eight out of 10 breast cancers are found in women over the age of 50.
- About 1 in 8 U.S. women (just under 12%) will develop invasive breast cancer over the course of her lifetime.
- The risk of getting breast cancer is higher among women who have a close blood relative with this disease.
- Having a mother, sister or daughter with breast cancer nearly doubles a woman’s risk.
- About 5-10% of breast cancers can be linked to gene mutations (abnormal changes) inherited from one’s mother or father. Mutations of the BRCA1 and BRCA2 genes are the most common.
- Women with these mutations have up to an 80% risk of developing breast cancer during their lifetime, and they are more likely to be diagnosed at a younger age (before menopause).
- An increased ovarian cancer risk is also associated with these genetic mutations.
- About 85% of breast cancers occur in women who have no family history of breast cancer. These occur due to genetic mutations that happen as a result of the aging process and life in general, rather than inherited mutations.
- A woman with cancer in one breast has a greater chance of getting a new cancer in the other breast.
- White woman are slightly more likely to get breast cancer than are African-American women. But African Americans are more likely to die of this type of cancer.
The Main Types of Cancer:
Ductal carcinoma in situ (DCIS)
- This is the most common type of noninvasive breast cancer. DCIS means that the cancer is confined to the ducts.
- This term is used for early stage cancer, when it is confined to the place where it started.
Lobular carcinoma in situ (LCIS)
- This condition begins in the milk-making glands but does not go through the wall of the lobules. Although not a true cancer, having LCIS increases a woman’s risk of getting cancer later. For this reason, it’s important for women with LCIS to follow the screening guidelines for breast cancer.
Infiltrating (invasive) ductal carcinoma (IDC)
- This cancer starts in a milk passage or duct, breaks through the wall of the duct and invades the fatty tissue of the breast. From there it can spread to other parts of the body. IDC is the most common type of breast cancer. It accounts for about 80 percent of invasive breast cancers.
Infiltrating (invasive) lobular carcinoma (ILC)
- This cancer starts in the milk glands or lobules. It can spread to other parts of the body. About 10 percent of invasive breast cancers are of this type.
Breast Cancer Diagnosis
Possible signs of breast cancer include a lump or change in the breast.
Breast cancer may cause any of the following signs and symptoms…
Check with your doctor if any of the following problems occur:
- A lump or thickening in or near the breast or in the underarm area.
- A change in the size or shape of the breast.
- A dimple or puckering in the skin of the breast.
- A nipple turned inward into the breast.
- Fluid, other than breast milk, from the nipple, especially if it’s bloody.
- Scaly, red, or swollen skin on the breast, nipple, or areola (the dark area of skin that is around the nipple).
- Dimples in the breast that look like the skin of an orange, called peau d’orange.
Other conditions that are not breast cancer may cause these same symptoms. Tests that examine the breasts are used to detect (find) and diagnose breast cancer.
A doctor should be seen if changes in the breast are noticed:
The following tests and procedures may be used:
- Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
- Mammogram: An x-ray of the breast.
- Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
- Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
- Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. If a lump in the breast is found, the doctor may need to remove a small piece of the lump. Four types of biopsies are as follows:
- Excisional biopsy: The removal of an entire lump of tissue.
- Incisional biopsy: The removal of part of a lump or a sample of tissue.
- Core biopsy: The removal of tissue using a wide needle.
- Fine-needle aspiration (FNA) biopsy: The removal of tissue or fluid, using a thin needle.
If cancer is found, tests are done to study the cancer cells. Decisions about the best treatment are based on the results of these tests.
The tests give information about:
- how quickly the cancer may grow.
- how likely it is that the cancer will spread through the body.
- how well certain treatments might work.
- how likely the cancer is to recur (come back).
Tests include the following:
- Estrogen and progesterone receptor test: A test to measure the amount of estrogen and progesterone (hormones) receptors in cancer tissue. If there are more estrogen and progesterone receptors than normal, the cancer may grow more quickly. The test results show whether treatment to block estrogen and progesterone may stop the cancer from growing.
- Human epidermal growth factor type 2 receptor (HER2/neu) test: A laboratory test to measure how many HER2/neu genes there are and how much HER2/neu protein is made in a sample of tissue. If there are more HER2/neu genes or higher levels of HER2/neu protein than normal, the cancer may grow more quickly and is more likely to spread to other parts of the body. The cancer may be treated with drugs that target the HER2/neu protein, such as trastuzumab (Herceptin) and lapatinib (Tykerb).
- Multigene tests: Tests in which samples of tissue are studied to look at the activity of many genes at the same time. These tests may help predict whether cancer will spread to other parts of the body or recur (come back).
- Oncotype DX: This test helps predict whether stage I or stage II breast cancer that is estrogen receptor positive and node-negative will spread to other parts of the body. If the risk of the cancer spreading is high, chemotherapy may be given to lower the risk.
- MammaPrint: This test helps predict whether stage I or stage II breast cancer that is node-negative will spread to other parts of the body. If the risk of the cancer spreading is high, chemotherapy may be given to lower the risk.
Certain factors affect prognosis (chance of recovery) and treatment options.
The prognosis (chance of recovery) and treatment options depend on the following:
- The stage of the cancer (the size of the tumor and whether it is in the breast only or has spread to lymph nodes or other places in the body).
- The type of breast cancer.
- Estrogen receptor and progesterone receptor levels in the tumor tissue.
- Human epidermal growth factor type 2 receptor (HER2/neu) levels in the tumor tissue.
- Whether the tumor tissue is triple-negative (cells that do not have estrogen receptors, progesterone receptors, or high levels of HER2/neu).
- How fast the tumor is growing.
- How likely the tumor is to recur (come back).
- A woman’s age, general health, and menopausal status (whether a woman is still having menstrual periods).
- Whether the cancer has just been diagnosed or has recurred (come back).
After breast cancer has been diagnosed, tests are done to find out if cancer cells have spread within the breast or to other parts of the body.
The process used to find out whether the cancer has spread within the breast or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment.
The following tests and procedures may be used in the staging process:
- CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
- Bone scan: A procedure to check if there are rapidly dividing cells, such as cancer cells, in the bone. A very small amount of radioactive material is injected into a vein and travels through the bloodstream. The radioactive material collects in the bones and is detected by a scanner.
- PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.
The Three Ways Cancer Spreads in the Body.
- Through tissue. Cancer invades the surrounding normal tissue.
- Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
- Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.
When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.
Stages of breast cancer:
Stage 0 (carcinoma in situ)Stage IStage IIStage IIIStage IV
There are 2 types of breast carcinoma in situ:
- Ductal carcinoma in situ (DCIS) is a noninvasive condition in which abnormal cells are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, DCIS may become invasive cancer and spread to other tissues, although it is not known at this time how to predict which lesions will become invasive.
- Lobular carcinoma in situ (LCIS) is a condition in which abnormal cells are found in the lobules of the breast. This condition seldom becomes invasive cancer; however, having lobular carcinoma in situ in one breast increases the risk of developing breast cancer in either breast.
Pea, peanut, walnut, and lime show tumor sizes.
In stage I, cancer has formed. Stage I is divided into stages IA and IB.
- In stage IA, the tumor is 2 centimeters or smaller and has not spread outside the breast.
- In stage IB, either:
- no tumor is found in the breast, but small clusters of cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes; or
- the tumor is 2 centimeters or smaller and small clusters of cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes.
Stage II is divided into stages IIA and IIB.
- In stage IIA:
- no tumor is found in the breast, but cancer is found in the axillary lymph nodes (lymph nodes under the arm); or
- the tumor is 2 centimeters or smaller and has spread to the axillary lymph nodes; or
- the tumor is larger than 2 centimeters but not larger than 5 centimeters and has not spread to the axillary lymph nodes.
- In stage IIB, the tumor is either:
- larger than 2 centimeters but not larger than 5 centimeters and has spread to the axillary lymph nodes
- larger than 5 centimeters but has not spread to the axillary lymph nodes.
Stage III is divided in IIIA, IIIB and IIIC
In stage IIIA:
- No tumor is found in the breast. Cancer is found in axillary lymph nodes that are attached to each other or to other structures, or cancer is found in lymph nodes near the breastbone; or
- the tumor is 2 centimeters or smaller. Cancer has spread to axillary lymph nodes that are attached to each other or to other structures
- the tumor is larger than 2 centimeters but not larger than 5 centimeters. Cancer has spread to axillary lymph nodes that are attached to each other or to other structures
- the tumor is larger than 5 centimeters. Cancer has spread to axillary lymph nodes that may be attached to each other or to other structures
In stage IIIB, the tumor may be any size and cancer:
- has spread to the chest wall and/or the skin of the breast; and
- may have spread to axillary lymph nodes that may be attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone.
- Cancer that has spread to the skin of the breast is inflammatory breast cancer.
- In stage IIIC, no tumor is found in the breast or the tumor may be any size and may have spread to the chest wall and/or the skin of the breast.
- has spread to lymph nodes above or below the collarbone; and
- may have spread to axillary lymph nodes or to lymph nodes near the breastbone.
- Cancer that has spread to the skin of the breast is inflammatory breast cancer.
- In stage IV, the cancer has spread to other organs of the body, most often the bones, lungs, liver, or brain.
Recurrent And Metastatic Cancer:
Locally recurrent cancer is the return of cancer to the area where a patient initially had it. When breast cancer spreads to other parts of the body such as bones, liver, lungs or brain, it is called metastatic breast cancer. The sites where the cancer shows up are metastatic sites.
Breast Cancer Treatment
SurgerySentinel Lymph Node Biopsy Followed by SurgeryRadiation TherapyChemotherapyHormone TherapyTargeted Therapy
Most patients with breast cancer have surgery to remove the cancer from the breast. Some of the lymph nodes under the arm are usually taken out and looked at under a microscope to see if they contain cancer cells.
Breast-conserving surgery, an operation to remove the cancer but not the breast itself, includes the following:
- Lumpectomy: Surgery to remove a tumor (lump) and a small amount of normal tissue around it.
- Partial mastectomy: Surgery to remove the part of the breast that has cancer and some normal tissue around it. The lining over the chest muscles below the cancer may also be removed. This procedure is also called a segmental mastectomy.
Other types of surgery include the following:
- Total mastectomy: Surgery to remove the whole breast that has cancer. This procedure is also called a simple mastectomy. Some of the lymph nodes under the arm may be removed for biopsy at the same time as the breast surgery or after. This is done through a separate incision.
Chemotherapy may be given before surgery to remove the tumor. When given before surgery, chemotherapy will shrink the tumor and reduce the amount of tissue that needs to be removed during surgery. Treatment given before surgery is called neoadjuvant therapy.
Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given radiation therapy, chemotherapy, or hormone therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.
Patients who are treated with breast-conserving surgery may also have some of the lymph nodes under the arm removed for biopsy. This procedure is called lymph node dissection. It may be done at the same time as the breast-conserving surgery or after. Lymph node dissection is done through a separate incision.
If a patient is going to have a mastectomy, breast reconstruction (surgery to rebuild a breast’s shape after a mastectomy) may be considered. Breast reconstruction may be done at the time of the mastectomy or at a future time. The reconstructed breast may be made with the patient’s own (nonbreast) tissue or by using implants filled with saline or silicone gel.
Sentinel lymph node biopsy is the removal of the sentinel lymph node during surgery. The sentinel lymph node is the first lymph node to receive lymphatic drainage from a tumor. It is the first lymph node the cancer is likely to spread to from the tumor. A radioactive substance and/or blue dye is injected near the tumor. The substance or dye flows through the lymph ducts to the lymph nodes. The first lymph node to receive the substance or dye is removed. A pathologist views the tissue under a microscope to look for cancer cells. If cancer cells are not found, it may not be necessary to remove more lymph nodes. After the sentinel lymph node biopsy, the surgeon removes the tumor (breast-conserving surgery or mastectomy).
Sentinel lymph node biopsy of the breast. A radioactive substance and/or blue dye is injected near the tumor (first panel). The injected material is detected visually and/or with a probe that detects radioactivity (middle panel). The sentinel nodes (the first lymph nodes to take up the material) are removed and checked for cancer cells (last panel).
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing.
There are two types of radiation therapy.
External radiation therapy uses a machine outside the body to send radiation toward the cancer.
Brachytherapy– Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.
Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. Hormones are substances produced by glands in the body and circulated in the bloodstream. Some hormones can cause certain cancers to grow. If tests show that the cancer cells have places where hormones can attach (receptors), drugs, surgery, or radiation therapy is used to reduce the production of hormones or block them from working. The hormone estrogen, which makes some breast cancers grow, is made mainly by the ovaries. Treatment to stop the ovaries from making estrogen is called ovarian ablation.
Hormone therapy with tamoxifen is often given to patients with early stages of breast cancer and those with metastatic breast cancer (cancer that has spread to other parts of the body). Hormone therapy with tamoxifen or estrogens can act on cells all over the body and may increase the chance of developing endometrial cancer. Women taking tamoxifen should have a pelvic exam every year to look for any signs of cancer. Any vaginal bleeding, other than menstrual bleeding, should be reported to a doctor as soon as possible.
Hormone therapy with an aromatase inhibitor is given to some postmenopausal women who have hormone-dependent breast cancer. Hormone-dependent breast cancer needs the hormone estrogen to grow. Aromatase inhibitors decrease the body’s estrogen by blocking an enzyme called aromatase from turning androgen into estrogen.
For the treatment of early stage breast cancer, certain aromatase inhibitors may be used as adjuvant therapy instead of tamoxifen or after 2 or more years of tamoxifen.
Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells.
Trastuzumab (Herceptin) is a monoclonal antibody that blocks the effects of the growth factor protein HER2, which sends growth signals to breast cancer cells. About one-fourth of patients with breast cancer have tumors that may be treated with trastuzumab combined with chemotherapy.
Tyrosine kinase inhibitors are targeted therapy drugs that block signals needed for tumors to grow. Tyrosine kinase inhibitors may be used in combination with other anticancer drugs as adjuvant therapy.
Lapatinib is a tyrosine kinase inhibitor that blocks the effects of the HER2 protein and other proteins inside tumor cells. It may be used with other drugs to treat patients with HER2-positive breast cancer that has progressed following treatment with trastuzumab.
PARP inhibitors are a type of targeted therapy that block DNA repair and may cause cancer cells to die. PARP inhibitor therapy is being studied for the treatment of triple-negative breast cancer.