Breast cancer (malignant breast neoplasm) is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas. Breast cancer is a disease of humans and other mammals; while the overwhelming majority of cases in humans are women, men can also develop breast cancer.
The size, stage, rate of growth, and other characteristics of the tumor determine the kinds of treatment. Treatment may include surgery, drugs (hormonal therapy and chemotherapy), radiation and/or immunotherapy. Surgical removal of the tumor provides the single largest benefit, with surgery alone being capable of producing a cure in many cases. To somewhat increase the likelihood of long-term disease-free survival, several chemotherapy regimens are commonly given in addition to surgery. Most forms of chemotherapy kill cells that are dividing rapidly anywhere in the body, and as a result cause temporary hair loss and digestive disturbances. Radiation may be added to kill any cancer cells in the breast that were missed by the surgery, which usually extends survival somewhat, although radiation exposure to the heart may cause heart failure in the future. Some breast cancers are sensitive to hormones such as estrogen and/or progesterone, which makes it possible to treat them by blocking the effects of these hormones.
Prognosis and survival rate varies greatly depending on cancer type and staging. With best treatment and dependent on staging, 5-year relative survival varies from 98% to 23, with an overall survival rate of 85%.
Source: Wikipedia. Visit their website for more information on Breast Cancer.
Breast cancer is a cancer that starts in the tissues of the breast. There are two main types of breast cancer:
- Ductal carcinoma starts in the tubes (ducts) that move milk from the breast to the nipple. Most breast cancers are of this type.
- Lobular carcinoma starts in the parts of the breast, called lobules, that produce milk.
In rare cases, breast cancer can start in other areas of the breast. Breast cancer may be invasive or noninvasive. Invasive means it has spread from the milk duct or lobule to other tissues in the breast. Noninvasive means it has not yet invaded other breast tissue. Noninvasive breast cancer is called "in situ."
- Ductal carcinoma in situ (DCIS), or intraductal carcinoma, is breast cancer in the lining of the milk ducts that has not yet invaded nearby tissues. It may progress to invasive cancer if untreated.
- Lobular carcinoma in situ (LCIS) is a marker for an increased risk of invasive cancer in the same or both breasts.
Causes, Incidence, and Risk Factors
Over the course of a lifetime, 1 in 8 women will be diagnosed with breast cancer. Risk factors you cannot change include:
- Age and gender -- Your risk of developing breast cancer increases as you get older. Most advanced breast cancer cases are found in women over age 50. Women are 100 times more likely to get breast cancer than men.
- Family history of breast cancer -- You may also have a higher risk for breast cancer if you have a close relative who has had breast, uterine, ovarian, or colon cancer. About 20 - 30% of women with breast cancer have a family history of the disease.
- Genes -- Some people have genes that make them more likely to develop breast cancer. The most common gene defects are found in the BRCA1 and BRCA2 genes. These genes normally produce proteins that protect you from cancer. If a parent passes you a defective gene, you have an increased risk for breast cancer. Women with one of these defects have up to an 80% chance of getting breast cancer sometime during their life.
- Menstrual cycle -- Women who got their periods early (before age 12) or went through menopause late (after age 55) have an increased risk for breast cancer.
Other risk factors include:
- Alcohol use -- Drinking more than 1 - 2 glasses of alcohol a day may increase your risk for breast cancer.
- Childbirth -- Women who have never had children or who had them only after age 30 have an increased risk for breast cancer. Being pregnant more than once or becoming pregnant at an early age reduces your risk of breast cancer.
- DES -- Women who took diethylstilbestrol (DES) to prevent miscarriage may have an increased risk of breast cancer after age 40. This drug was given to the women in the 1940s - 1960s.
- Hormone replacement therapy (HRT) -- You have a higher risk for breast cancer if you have received hormone replacement therapy with estrogen for several years or more.Obesity -- Obesity has been linked to breast cancer, although this link is controversial. The theory is that obese women produce more estrogen, which can fuel the development of breast cancer.
- Radiation -- If you received radiation therapy as a child or young adult to treat cancer of the chest area, you have a much higher risk for developing breast cancer. The younger you started such radiation and the higher the dose, the higher your risk -- especially if the radiation was given during breast development.
Breast implants, using antiperspirants, and wearing underwire bras do not raise your risk for breast cancer. There is no evidence of a direct link between breast cancer and pesticides.The National Cancer Institute provides an online tool to help you figure out your risk of breast cancer. See: www.cancer.gov/bcrisktool
Early breast cancer usually does not cause symptoms. This is why regular breast exams are important. As the cancer grows, symptoms may include:
- Breast lump or lump in the armpit that is hard, has uneven edges, and usually does not hurt
- Change in the size, shape, or feel of the breast or nipple -- for example, you may have redness, dimpling, or puckering that looks like the skin of an orange
- Fluid coming from the nipple -- may be bloody, clear to yellow, green, and look like pus
Men can get breast cancer, too. Symptoms include breast lump and breast pain and tenderness.
Symptoms of advanced breast cancer may include:
- Bone pain
- Breast pain or discomfort
- Skin ulcers
- Swelling of one arm (next to the breast with cancer)
- Weight loss
Signs and Tests
The doctor will ask you about your symptoms and risk factors. Then the doctor will perform a physical exam, which includes both breasts, armpits, and the neck and chest area. Tests used to diagnose and monitor patients with breast cancer may include:
- Breast MRI to help better identify the breast lump or evaluate an abnormal change on a mammogram
- Breast ultrasound to show whether the lump is solid or fluid-filled
- Breast biopsy, using methods such as needle aspiration, ultrasound-guided, stereotactic, or open
- CT scan to see if the cancer has spread
- Mammography to screen for breast cancer or help identify the breast lump
- PET scan
- Sentinal lymph node biopsy to see if the cancer has spread
If your doctor learns that you do have breast cancer, more tests will be done to see if the cancer has spread. This is called staging. Staging helps guide future treatment and follow-up and gives you some idea of what to expect in the future. Breast cancer stages range from 0 to IV. The higher the staging number, the more advanced the cancer.
Treatment is based on many factors, including:
- Type and stage of the cancer
- Whether the cancer is sensitive to certain hormones
- Whether the cancer overproduces (overexpresses) a gene called HER2/neu
In general, cancer treatments may include:
- Chemotherapy medicines to kill cancer cells
- Radiation therapy to destroy cancerous tissue
- Surgery to remove cancerous tissue -- a lumpectomy removes the breast lump; mastectomy removes all or part of the breast and possible nearby structures
Hormonal therapy is prescribed to women with ER-positive breast cancer to block certain hormones that fuel cancer growth.
- An example of hormonal therapy is the drug tamoxifen. This drug blocks the effects of estrogen, which can help breast cancer cells survive and grow. Most women with estrogen-sensitive breast cancer benefit from this drug.
- Another class of hormonal therapy medicines called aromatase inhibitors, such as exemestane (Aromasin), have been shown to work just as well or even better than tamoxifen in postmenopausal women with breast cancer. Aromatase inhibitors block estrogen from being made.
Targeted therapy, also called biologic therapy, is a newer type of cancer treatment. This therapy uses special anticancer drugs that target certain changes in a cell that can lead to cancer. One such drug is trastuzumab (Herceptin). It may be used for women with HER2-positive breast cancer. Cancer treatment may be local or systemic.
- Local treatments involve only the area of disease. Radiation and surgery are forms of local treatment.
- Systemic treatments affect the entire body. Chemotherapy is a type of systemic treatment.
Most women receive a combination of treatments. For women with stage I, II, or III breast cancer, the main goal is to treat the cancer and prevent it from returning (curing). For women with stage IV cancer, the goal is to improve symptoms and help them live longer. In most cases, stage IV breast cancer cannot be cured.
- Stage 0 and DCIS -- Lumpectomy plus radiation or mastectomy is the standard treatment. There is some controversy on how best to treat DCIS.
- Stage I and II -- Lumpectomy plus radiation or mastectomy with some sort of lymph node removal is the standard treatment. Hormone therapy, chemotherapy, and biologic therapy may also be recommended following surgery.
- Stage III -- Treatment involves surgery, possibly followed by chemotherapy, hormone therapy, and biologic therapy.
- Stage IV -- Treatment may involve surgery, radiation, chemotherapy, hormonal therapy, or a combination of these treatments.
After treatment, some women will continue to take medications such as tamoxifen for a period of time. All women will continue to have blood tests, mammograms, and other tests after treatment. Women who have had a mastectomy may have reconstructive breast surgery, either at the same time as the mastectomy or later
Source: National Center for Biotechnology Information. Visit their website for more information regarding Carcinoid Cancer.
Facts about Breast Cancer in the United States
- About 1 in 8 U.S. women (about 13%) will develop invasive breast cancer over the course of her lifetime.
- In 2021, an estimated 281,550 new cases of invasive breast cancer are expected to be diagnosed in women in the U.S., along with 49,290 new cases of non-invasive (in situ) breast cancer.
- About 2,650 new cases of invasive breast cancer are expected to be diagnosed in men in 2021. A man’s lifetime risk of breast cancer is about 1 in 833.
- About 43,600 women in the U.S. are expected to die in 2021 from breast cancer. Death rates have been steady in women under 50 since 2007, but have continued to drop in women over 50. The overall death rate from breast cancer decreased by 1% per year from 2013 to 2018. These decreases are thought to be the result of treatment advances and earlier detection through screening.
- For women in the U.S., breast cancer death rates are higher than those for any other cancer, besides lung cancer.
- As of January 2021, there are more than 3.8 million women with a history of breast cancer in the U.S. This includes women currently being treated and women who have finished treatment.
- Breast cancer is the most commonly diagnosed cancer among American women. In 2021, it's estimated that about 30% of newly diagnosed cancers in women will be breast cancers.
- Breast cancer became the most common cancer globally as of 2021, accounting for 12% of all new annual cancer cases worldwide, according to the World Health Organization.
- In women under 45, breast cancer is more common in Black women than white women. Overall, Black women are more likely to die of breast cancer. For Asian, Hispanic, and Native-American women, the risk of developing and dying from breast cancer is lower. Ashkenazi Jewish women have a higher risk of breast cancer because of a higher rate of BRCA mutations.
- Breast cancer incidence rates in the U.S. began decreasing in the year 2000, after increasing for the previous two decades. They dropped by 7% from 2002 to 2003 alone. One theory is that this decrease was partially due to the reduced use of hormone replacement therapy (HRT) by women after the results of a large study called the Women’s Health Initiative were published in 2002. These results suggested a connection between HRT and increased breast cancer risk. In recent years, incidence rates have increased slightly by 0.5% per year.
- A woman’s risk of breast cancer nearly doubles if she has a first-degree relative (mother, sister, daughter) who has been diagnosed with breast cancer. Less than 15% of women who get breast cancer have a family member diagnosed with it.
- About 5-10% of breast cancers can be linked to known gene mutations inherited from one’s mother or father. Mutations in the BRCA1 and BRCA2 genes are the most common. On average, women with a BRCA1 mutation have up to a 72% lifetime risk of developing breast cancer. For women with a BRCA2 mutation, the risk is 69%. Breast cancer that is positive for the BRCA1 or BRCA2 mutations tends to develop more often in younger women. An increased ovarian cancer risk is also associated with these genetic mutations. In men, BRCA2 mutations are associated with a lifetime breast cancer risk of about 6.8%; BRCA1 mutations are a less frequent cause of breast cancer in men.
- 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.
- The most significant risk factors for breast cancer are sex (being a woman) and age (growing older).
1. American Cancer Society. How Common Is Breast Cancer? Jan. 2021. Available at: WEBSITE
2. American Cancer Society. Key Statistics for Breast Cancer in Men. Jan. 2021. Available at: WEBSITE
3. American Cancer Society. Cancer Facts & Figures 2021. Available at: WEBSITE
4. Reuters. Breast cancer overtakes lung as most common cancer-WHO. Feb. 2021. Available at: WEBSITE
5. National Cancer Institute. BRCA Gene Mutations: Cancer Risk and Genetic Testing. Nov. 2020. Available at: WEBSITE
6. American Cancer Society. Breast Cancer Risk Factors You Cannot Change. Sept. 2019. Available at: WEBSITE