
According to the Centers for Disease Control and Prevention, progressing age is probably the most important risk factor for breast cancer. As women age, the risk of breast cancer increases.
- Most cases of breast cancer are seen among women who are about 50 to 69 years old and have attained menopause.
- However, in case of the presence of predisposing factors, cancer may start sooner, such as 40 years.
The risk factors for developing breast cancer are of two types, nonmodifiable and modifiable factors.
11 nonmodifiable risk factors for breast cancer
- Sex: Breast cancer may affect both men and women. However, according to the American Cancer Society, women are 100 times more likely to acquire breast cancer than men.
- Genetic mutations: Many genes associated with breast cancer have been found. The breast cancer genes are BRCA1 and BRCA2. Changes in these genes increase the chance of developing breast and other cancers, such as ovarian cancer. These alterations can result in an 80 percent lifetime risk of getting breast cancer. Alterations in other genes, such as p53, PTEN, and CHEK2, increase the risk of breast cancer.
- Dense breast tissue: Women with dense breast tissue have less fat in their breasts and more fibrous or glandular tissue. Having high-density breast tissue than breast fat increases the risk of acquiring breast cancer.
- Early menstruation and late menopause: It is well established that there is a significant association between breast cancer and female hormones estrogen. Attaining early menstruation (before 12 years) or late menopause (after 55 years) cause prolonged exposure to estrogen hormone in women. This increases the risk of developing breast cancer.
- Personal history of breast conditions or cancer: There is an elevated risk of breast cancer following a breast biopsy, which revealed lobular carcinoma in situ (LCIS) or atypical hyperplasia of the breast. A previous history of breast cancer and treatment may cause a relapse of cancer after several years.
- Family history: The risk of breast cancer increases if any other woman in the family, such as a mother, sister, or daughter, is diagnosed with breast cancer.
- Late pregnancy: Women who have their first child beyond the age of 35 years may be at a slightly greater risk of breast cancer.
- Nulliparity: Breast cancer is more common in women who have never been pregnant than in women who have had one or more pregnancies.
- Postmenopausal hormonal therapy: Women who are on hormone replacement therapy with both estrogen and progesterone after attaining menopause have an increased risk of breast cancer. When women quit taking these drugs, their risk reduces.
- Prolonged use of oral contraceptives: Women who use oral contraceptives (birth control pills) have a slightly increased chance of developing breast cancer. When the pills are withdrawn, the risk reduces to baseline in about 10 years.
- Radiation exposure: Women who received chest radiation treatments during childhood or as young adults, their chances of developing breast cancer are increased.

SLIDESHOW
Breast Cancer Awareness: Symptoms, Diagnosis, and Treatment See Slideshow4 modifiable risk factors for breast cancer
- Overweight: Obesity or being overweight raises the risk of breast cancer. More body fat means more estrogen, and estrogen promotes tumor development. Maintain a healthy weight by being active and eating a well-balanced diet.
- Alcohol consumption: Drinking alcohol raises the chance of developing breast cancer. The danger rises with the increase in the intake of total alcohol amount. The process through which alcohol is digested in a woman's body may raise estrogen levels in the bloodstream, increasing the risk of breast cancer.
- Being physically inactive: Regular physical exercise lowers the incidence of breast cancer, especially in menopausal women.
- Smoking: Tobacco use increases the risk of at least 15 malignancies, including breast cancer. Women who smoke are more likely to acquire breast cancer than nonsmokers. Long-term secondhand smoking exposure may also increase the risk.
What is breast cancer?
Breast cancer is a type of cancer that develops in the tissues of the breast. It is the most diagnosed cancer in women globally, accounting for one in every eight cancer cases. It is a common malignancy in both sexes and the main cause of cancer deaths in women. Though it affects both men and women, male breast cancer is rare.
There is a good probability of recovery if it is diagnosed in the early stages. So, all women should check their breasts regularly for any abnormal breast lumps and nipple discharge. Seek immediate medical attention if any abnormalities are noted. Following a regimen of regular screening for breast cancers will help detect minor changes in the breast tissue prompting early treatment.
Health News
- What Is Avascular Necrosis and How Does It Affect Bones?
- The Arch of the Human Foot Was Key to Upright Walking, Scientists Say
- Worried About Cataracts? Here's What You Need to Know
- FDA Issues Warning About Compounded Versions of Wegovy, Ozempic
- Sick Restaurant Workers Fuel Many Foodborne Illness Outbreaks
More Health News »
3 types of breast cancers
- Ductal carcinoma: Ductal carcinoma is the most common type of breast cancer. Ductal carcinoma is cancer of the epithelial cells lining the milk ducts that carry milk from lobules to the nipples of the breast. Ductal carcinoma in situ (DCIS) is also called intraductal carcinoma and is a kind of noninvasive breast cancer.
- Lobular carcinoma: Lobular carcinoma is a type of breast cancer that develops in the lobules or ducts (milk glands) of the breast. This type of cancer is called adenocarcinoma.
- Invasive breast cancer: Breast cancer that is invasive or has spread from its origin to surrounding normal breast tissue is called invasive breast cancer.
Invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) are the most common types. Invasive ductal carcinoma accounts for about 70 to 80 percent of all breast cancers.
2 types of invasive breast cancer
- Triple-negative breast cancer: Triple-negative breast cancer is an aggressive form of invasive breast cancer in which cancer cells lack estrogen or progesterone receptors (ER or PR) and produce little to no HER2 protein. So, all three tests are done to detect receptors or protein negative. It accounts for about 15 percent of all breast cancers and is a tough malignancy to cure.
- Inflammatory breast cancer: Inflammatory breast cancer is a kind of aggressive invasive breast cancer in which cancer cells obstruct lymph arteries in the skin, giving the breast an inflamed appearance. It is uncommon, accounting for roughly one to five percent of all breast cancers.
3 less common breast cancers
- Paget disease: Breast Paget disease is uncommon, accounting for about one to three percent of all instances of breast cancer. It begins in the breast ducts and spreads to the nipple skin and subsequently, to the areola (the dark circle around the nipple).
- Phyllodes tumor: Phyllodes tumors are uncommon breast cancers. In contrast to carcinomas, which originate in the ducts or lobules, they develop in the connective tissue (stroma) of the breast. The majority are benign, but some are cancerous.
- Angiosarcoma: Breast sarcomas are extremely uncommon, accounting for fewer than one percent of all breast malignancies. Angiosarcoma begins in the cells that line blood and lymph arteries. It can affect either the breast tissue or the breast skin. Some may be connected to earlier radiation therapy in that location.
7 signs and symptoms of breast cancer
The signs and symptoms of breast cancer vary among women. It is crucial to understand even slight changes in the breast.
- Breast lump: Most breast lumps are not cancerous, and they are referred to as benign lumps. It is always advised to get evaluated for a breast lump by a doctor to confirm if it is benign or malignant.
- The following are the most common benign breast lumps:
- Feeling a lump is often common before every period.
- The presence of cysts or fluid-filled sacs in the breast is common.
- Fibroadenoma is mostly seen in women younger than 30 years. It is a benign breast tumor made up of both glandular and stromal tissue.
- The following are the most common benign breast lumps:
- Changes in the breast: A cancerous breast may appear larger, have a different shape than usual, and feel different. Many healthy women experience lumps and soreness in the breasts right before their menstruation. Similar changes are seen with breast cancer, so it is recommended to pay attention to the size, shape, and texture of one’s breast.
- Skin changes: Puckering, dimpling, rash, or redness of the breast skin are examples of skin changes. Some women get a rash or redness around their nipples and surrounding skin. The skin may resemble orange peel or have a distinct texture.
- Changes in nipple positioning: One of the nipples may turn in or sink into the breast. It may seem or feel different than normal. Consult the doctor if any changes out of the ordinary are seen with one or both nipples.
- Nipple discharge: Discharge from a woman's nipple who is not pregnant or nursing could be an indication of malignancy. However, this can be caused by other medical issues.
- Breast pain: Breast discomfort is usually not caused by cancer. It is common to experience soreness in one or both breasts for a short period. Sometimes, there may not be an evident cause for the discomfort even after undergoing several tests. However, it is advisable to consult a doctor to get evaluated for breast discomfort.
- Lump in armpit: Usually, lymph nodes are not palpable unless there is any possible infection or illness. Breast cancer can spread to adjacent lymph nodes causing lumps in the armpit and even around the collar bone.
Though most of the signs and symptoms incline toward benign conditions of the breast, it is always advisable to get evaluated by a doctor and rule out malignancy.
Subscribe to MedicineNet's Cancer Report Newsletter
By clicking "Submit," I agree to the MedicineNet Terms and Conditions and Privacy Policy. I also agree to receive emails from MedicineNet and I understand that I may opt out of MedicineNet subscriptions at any time.
How is breast cancer diagnosed?
Any structural changes in the breast or the presence of a lump or discomfort in the breast should be evaluated.
- Mammography: Mammography is an X-ray examination that is performed to inspect the breasts. This imaging technique includes exposing the breasts to a low dose of ionizing radiation to capture images of the interior of the breasts. It is recommended that all women aged 45 to 50 years, who are at low risk of developing breast cancers, undergo mammography one or two times each year.
- Breast ultrasound: Breast ultrasound creates images of the interior of the breasts using sound waves. Breast ultrasound can capture pictures of parts of the breast that mammography may not be able to view. It can help determine if a breast lump is solid or cystic.
- Magnetic resonance imaging (MRI): A high magnetic field, radiofrequency pulses, and a computer will be used during breast MRI to obtain detailed images of the interior of the breasts. MRI is useful to assess breast tumors that are not visible on mammography or ultrasound, especially in women with thick breast tissue.
- Positron-emission tomography/computer tomography (PET/CT): A nuclear imaging technique combines PET and CT scans to provide pictures that highlight the anatomic site of abnormal metabolic activity inside the breasts. It can identify breast cancer, determine whether it has spread, evaluate the efficacy of a treatment plan and establish whether the disease has relapsed following treatment.
- Scintimammography: Scintimammography examines a breast abnormality using small quantities of radioactive material, a special camera, and a computer. Scintimammography can identify cancer even in the presence of thick breast tissue and breast implants. It can identify whether a biopsy is necessary, hence reducing unnecessary interventions. If these tests show that a lump is benign, no further action is required. A biopsy may be required if these tests do not reveal that the lump is benign.
- Breast lump biopsy: Breast lump biopsy is a procedure where a needle is inserted into the breast lump and some tissue is extracted. This procedure can be done under the guidance of X-rays, ultrasound, or MRI. The extracted breast tissue is studied under a microscope to look for abnormal cells. If cancer is detected in a biopsy, then treatment will be administered according to the stage and location of cancer.
From 
Cancer Resources
Featured Centers
Health Solutions From Our Sponsors
5 stages of breast cancer
Breast cancer progresses through five stages. These stages are defined by the size of the tumor, the involvement of lymph nodes, and if cancer has spread to other parts of the body.
- Stage 0: Cancer is noninvasive or in situ (DCIS, LCIS). There is no sign of the spread of cancer cells. Cancer is confined to the breast tissue where it began. Paget's disease is commonly diagnosed at stage 0.
- Stage I: Breast cancer is invasive, has modest tumor size, and has little nodal involvement.
- Stage II: The tumor size ranges from 2 to 50 mm, with or without nodal involvement.
- Stage III: The tumor is more than 50 mm in diameter, involves more than four lymph nodes, and is in the chest wall or skin.
- Stage IV: Stage IV breast cancer is also called metastatic breast cancer. Cancer has progressed to other regions of the body, including the bones, liver, and lungs, in addition to the breast and lymph nodes.
Stages I to III are further divided into subtypes based on the size of the tumor and location of distant metastasis, such as lymph nodes.
What are the treatment options for breast cancer?
Treatment for breast cancer is determined by the location of cancer, size, whether it has spread to other parts of the body, and overall health. A group of physicians and other experts decide on the best treatment to get the desired outcome.
- Surgery: Most individuals start their breast cancer treatment with surgery. There are various surgical methods, they include:
- Breast-conserving surgery: Breast-conserving surgery is referred to as wide local excision. Depending on the size and location of cancer, only the malignant lump with a border of normal breast tissue may be removed.
- Mastectomy: Mastectomy removal of the entire breast. A breast reconstruction surgery may follow mastectomy, where a muscle flap can be used to create a breast-like structure.
- Excision of lymph nodes: Breast cancer has the potential to spread to other regions of the body. It frequently spreads to the lymph nodes in the armpit (axilla) near the breast initially. They are removed while performing tumor removal from the breast, especially during mastectomy.
- Radiation therapy: High energy radiation is used to kill cancer cells in the breast. This usually follows breast conservative surgery to kill the remanent cancer cells.
- Chemotherapy: Chemotherapy drugs are injected into the veins to kill cancer cells. This is usually done after surgery. In some cases, chemotherapy is administered before surgery to shrink a large tumor for easy removal.
- Targeted cancer therapy: Targeted therapy can be administered along with chemotherapy for tumors that are caused by genetic mutations.
- Hormone therapy: Administration of estrogen and progesterone in women to disrupt cancer cells.
These treatments can be performed alone or in combination for better results.
Many women have no further difficulties following their initial breast cancer therapy. However, breast cancer can reoccur following treatment. So, it is recommended to follow up closely with a doctor regularly to evaluate for recurrence of abnormalities.
Health Solutions From Our Sponsors
Sun YS, Zhao Z, Yang ZN, et al. Risk Factors and Preventions of Breast Cancer. Int J Biol Sci. 2017;13(11):1387-1397. Published 2017 Nov 1. doi:10.7150/ijbs.21635
Cedars-Sinai. Breast Cancer Risk Factors: Age, Genetics & Others. https://www.cedars-sinai.org/programs/cancer/we-treat/breast/about/risk-factors.html
Breastcancer.org. Breast Cancer Risk Factors. https://www.breastcancer.org/risk/risk-factors
Top What Age Group Is Breast Cancer Most Common In Related Articles
Bone Marrow Transplantation for Breast Cancer
Bone marrow transplantation is a treatment option for metastatic breast cancer. Check out the center below for more medical references on breast cancer, including multimedia (slideshows, images, and quizzes), related disease conditions, treatment and diagnosis, medications, and prevention or wellness.Breast Cancer
Breast cancer is an invasive tumor that develops in the mammary gland. Breast cancer is detected via mammograms, breast self-examination (BSE), biopsy, and specialized testing on breast cancer tissue. Treatment of breast cancer may involve surgery, radiation, hormone therapy, chemotherapy, and targeted therapy. Breast cancer risk may be lowered by managing controllable risk factors.
What you should know about breast cancer
- Breast cancer is the most common cancer among American women.
- One in every eight women in the United States develops breast cancer.
- There are many types of breast cancer that differ in their capability of spreading (metastasize) to other body tissues.
- The causes of breast cancer are unknown, although medical professionals have identified a number of risk factors.
- There are 11 common types of breast cancer and 4 uncommon types of breast cancer.
- Breast cancer early signs and symptoms include
- a lump in the breast or armpit,
- bloody nipple discharge,
- inverted nipple,
- orange-peel texture or dimpling of the breast's skin (peau d'orange),
- breast pain or sore nipple,
- swollen lymph nodes in the neck or armpit, and
- a change in the size or shape of the breast or nipple.
- Breast cancer can also be symptom free, which makes following national screening recommendations an important practice.
- Breast cancer is diagnosed during a physical exam, by a self-exam of the breasts, mammography, ultrasound testing, and biopsy.
- Treatment of breast cancer depends on the type of cancer and its stage (0-IV) and may involve surgery, radiation, or chemotherapy.
Young Women & Breast Cancer
Is breast cancer genetic? Should I get tested for the BRCA gene? What every young women should know about breast cancer. Discover the signs and symptoms of breast cancer and other crucial breast cancer facts.Breast Cancer Follow-Up Self-Exam
A breast cancer follow-up self-exam is a test that may help a woman detect a recurrence of the disease. A woman should perform a monthly self-exam of both breasts as well as attend scheduled follow-up appointments to detect any breast cancer recurrence early. Lymph node involvement, tumor size, hormone receptor status, histologic grade, nuclear grade, and oncogene expression help determine the likelihood of a recurrence.Breast Cancer Prevention
Lifestyle changes, a healthy antioxidant-rich diet, exercise, and weight reduction can help reduce a woman's risk of developing breast cancer. It's important to be aware of how risk factors such as family history, lifestyle factors, breast conditions, radiation therapy, and hormonal factors may influence your chances of developing breast cancer. Mammography and breast self-examinations are crucial steps in breast cancer prevention.Breast Cancer Quiz
This Breast Cancer Quiz features signs, symptoms, facts, causes, common forms, terms, risk factors, statistics, and more. Increase your awareness of breast cancer now!What Should I Know About Breast Cancer?
Breast cancer is the most common non-skin cancer of American women, but it can also occur in men. Every year in the U.S., there are over 266,000 new diagnoses of breast cancer. A woman has a risk of one in eight for developing breast cancer at some point during her lifetime.
Everyday Habits to Lower Breast Cancer Risk
Concerned about your breast cancer risk? Here are everyday health habits you can adopt to improve your odds.Breast Cancer: Female Celebrities Who’ve Had Breast Cancer
Celebrities face medical challenges too, including breast cancer. Find out how actors, entertainers, and other famous women dealt with their big health challenges.Genetic Testing for Breast Cancer
Intensive genetic counseling is required before undergoing genetic tests for breast cancer. During this educational counseling session, the health care provider can fully explain the benefits and risks of genetic testing and answer any questions you may have. You will also be required to sign a consent form prior to participating in any genetic tests. The form is an agreement between you and your doctor, showing that you have discussed the test and how its results might affect your family.Male Breast Cancer
Male breast cancer accounts for 1% of all breast cancers, and most cases are found in men between the ages of 60 and 70. A man's risk of developing breast cancer is one in 1,000. Signs and symptoms include a firm mass located below the nipple and skin changes around the nipple, including puckering, redness or scaling, retraction and ulceration of the nipple. Treatment depends upon staging and the health of the patient.Radiation Therapy for Breast Cancer
Radiation therapy for breast cancer is a form of treatment that utilizes high-energy rays to kill cancer cells. Check out the center below for more medical references on breast cancer, including multimedia (slideshows, images, and quizzes), related disease conditions, treatment and diagnosis, medications, and prevention or wellness.Role of Estrogen Receptors in Breast Cancer
Estrogen receptors (ERs) are receptors that are activated by the hormone estrogen (one of the female sex hormones). They are found most commonly in the inner lining of the uterus (endometrium), breast cells, ovarian cells, and a part of the brain (the hypothalamus).Triple-Negative Breast Cancer
Triple-negative breast cancer is more common in Hispanic and African-American women. Signs and symptoms include a lump in the armpit or breast, nipple discharge and inversion, and changes in the breast's skin. Treatment may incorporate surgery, chemotherapy, and radiation therapy.Breast Cancer: Visual Guide to Male Breast Cancer
Breast cancer isn't just a woman's disease. Learn about the symptoms and treatment of male breast cancer, and find out what can put you at risk for this cancer.