Breast Cancer

Last Updated November 2023 | This article was created by editorial staff and reviewed by Kyle Bradford Jones, MD, FAAFP

What is breast cancer?

Breast cancer is a cancer that begins in breast tissue. It usually shows up as a tumor. There are three types of breast tumors.

  • Benign (not cancerous). Most of the tumors that develop in breast tissue are benign.
  • In situ. These tumors are cancerous. The cancer is confined to the breast duct or lobule. This type of breast cancer can almost always be cured with treatment.
  • Invasive. This is the most serious type of breast cancer. It is when the cancerous tumors have spread to other parts of the body.

Breast cancer is the second most common cancer among women (after skin cancer). The good news is that the rate of death from breast cancer has declined over the last few years. This is probably because more tumors have been found early. This is when treatment can help the most. Regular mammograms can help find breast cancers early.


Symptoms of breast cancer can include:

  • A lump in the breast
  • Change in size or shape of the breast
  • Dimpling or puckering of the skin of the breast
  • Nipple turned inward toward the breast
  • Scaly, red, or swollen skin on the breast, nipple, or areola (dark area of skin around the nipple
  • Discharge from the nipple

What causes breast cancer?

It is not known exactly what causes breast cancer. There are certain risk factors that seem to increase your chance of getting the disease. It’s estimated that about 10% of breast cancer cases are hereditary (run in the family). In many of these cases, you inherited a gene from your parents that has mutated (changed from its normal form). This mutated gene makes it more likely for a person to get breast cancer.

Everyone has two genes called BRCA1 and BRCA2. Normally, these genes help prevent cancer tumors from growing. But sometimes a person inherits a mutated form of BRCA1 or BRCA2 from his or her family. This person’s chance of getting breast cancer increases. Mutations in these genes have also been linked to ovarian cancer.

There are other mutated genes that may make it more likely for a person to get breast cancer. Scientists know about some of these genes. They are working to identify others.

Breast cancer in 2 or more first-degree relatives is a sign that the mutated form of BRCA1 or BRCA2 might run in your family. First-degree relatives include your parents, siblings, and children. Another sign is a first-degree relative who got breast cancer before the age of 50.

Does everyone who has family members with breast cancer have these mutated genes?

The chances of inheriting breast cancer aren’t high. This is true even if someone in your family has had the disease. Many people have had breast cancer without carrying a mutated form of BRCA1 or BRCA2. Anyone with first-degree relatives who have had breast cancer is at increased risk. But most people don’t get the inherited kind of breast cancer.

Talk with your doctor about your family history. He or she will want to know your relation to any family members who have had breast cancer. Your doctor will also want to know how old your relatives were when their breast cancer was diagnosed.

Should I have a test to find out if I carry the breast cancer gene?

Your doctor can help you decide if a gene test might be useful to you. He or she can also discuss the pros and cons of taking the test. Talking with a genetic counselor might also be helpful.

Think about how you would feel if the test results showed that you are at greater risk of getting breast cancer. Some people want to know if they have one of the mutated genes. Knowing instead of wondering helps them deal with the risk of breast cancer. It allows them and their doctors to watch more closely for early signs of cancer. But other people would rather not know they have the abnormal gene. They feel that it would be too hard to cope with. Talk with your doctor about your feelings.

How is breast cancer diagnosed?

If you notice a lump or other change in your breast, see your doctor right away. He or she will do a physical exam. They will ask you about your health history and your family’s history of breast cancer. They will carefully feel your breasts and under your arms for lumps.

If they find something abnormal, your doctor may order a mammogram. A mammogram is a special X-ray of your breasts. Your breast will be pressed between two plates. This spreads out your breast so that a better X-ray picture can be taken. The entire process usually takes about 20 minutes.

If the mammogram shows something, your doctor may order more tests. These include:

  • Ultrasound – high-energy sound waves bounce off organs and tissues to create a picture
  • MRI– uses a magnet, radio waves, and a computer to make detailed pictures
  • Bloodwork – blood samples are checked for signs of disease
  • Biopsy – cells or tissues are removed from the breast and looked at under a microscope. This helps find cancer cells

There are different kinds of biopsies that look for breast cancer. These include:

  • Excisional – an entire lump of tissue is removed
  • Incisional – part of a lump or a sample of tissue is removed
  • Core – a wide needle removes tissue
  • Fine-needle aspiration (FNA) – a thin needle removes tissue or fluid

If cancer cells are found in a biopsy, your doctor will do more testing. This will help him or her find out how quickly the cancer may grow, how likely it will spread, and how certain treatments might work.

Can breast cancer be prevented or avoided?

There are things you can do to reduce your risk of getting breast cancer. Lifestyle changes have been shown to decrease risk, even in high-risk women. These changes include:

  • Not smoking
  • Limiting alcohol
  • Eating a healthy diet
  • Keeping a healthy weight
  • Exercising regularly
  • Breastfeeding your babies if you can
  • Limiting hormone therapy
  • Minimizing exposure to radiation in screening tests if not medically necessary

You can’t always avoid breast cancer, but you can find it early. This increases your chances of a full, speedy recovery. There is no evidence that breast self-exams can help prevent breast cancer. The best way to find it early is with regular mammograms.

A mammogram is the most effective way to find breast cancer early. It can detect an abnormal area up to 2 years before it becomes large enough to feel. The American Academy of Family Physicians (AAFP) recommends all women 50 years of age and older get a mammogram every 2 years. If you have risk factors for breast cancer, your doctor may want you to have mammograms more often. He or she also may want you to start having them at a younger age.

Mammograms can be uncomfortable, but they don’t take very long. New technology is being developed that may improve the experience. You may find that scheduling your mammogram shortly after your period makes it less uncomfortable. Your breasts may be less tender at this time.

Doing these things gives you the best chance to find cancer as early as you can. Finding breast cancer early makes treatment much easier and more effective.


There are many treatment options for breast cancer. Your doctor may recommend more than one type of treatment. What is best for one person may not be the best treatment for you. Your doctor will make the decision based on several things, including:

  • Your general health
  • The stage of the cancer
  • Whether the tumor has hormone receptors
  • The size of the tumor
  • If you have gone through menopause

Available treatments include:

  • Lumpectomy – The tumor and a small amount of tissue around it is removed during surgery. Surgery is the most common treatment for breast cancer.
  • Mastectomy – If the cancer is widespread in the breast, all breast tissue is removed. This is called a mastectomy. If the cancer has spread to the underarm lymph nodes, the whole breast and most or all lymph nodes are removed. This is called a modified radical mastectomy.
  • Radiation therapy – High-energy rays are used to kill cancer cells. It may be used after surgery to destroy any cancer cells that are still there.
  • Hormone therapy – Lab tests could show that your breast cancer cells have hormone receptors. If they do, hormone therapy can prevent the cancer cells from using the natural hormones they need to grow.
  • Chemotherapy – Powerful drugs are used to kill cancer cells. They are given through an IV (directly into the vein) or in pill form. Chemotherapy can cause unpleasant side effects. These include weakness, tiredness, and hair loss.
  • Targeted therapy – Lab tests could show that your breast cancer cells have too much of a protein called HER2. If they do, you can receive targeted therapies. These block the action of the extra HER2 protein and stop growth. They can be given in an IV or as a pill.

Living with breast cancer

Many cases of breast cancer can be cured with treatment. How well you do after treatment depends on many things. This includes how early the cancer was diagnosed. Left untreated, breast cancer can spread to other parts of the body, including internal organs. This could cause serious health problems or be fatal. It is very important to get treatment as soon as possible.

Living with cancer during treatment can be stressful. Treatments can have different side effects on your body. Take good care of yourself. Eat a healthy diet, get plenty of sleep, and try to keep your energy up by staying mildly active.

Many women choose to do nothing and to be proud of their bodies after a mastectomy. Some women may choose to have a breast reconstruction. This is surgery that rebuilds the shape of the breast. If you don’t want more surgery, you have other options. Some women wear a breast form, a device that replaces the breast. They also may wear padding inside their bras.

Even after your cancer is gone, you are at higher risk of cancer returning to your body. You will need to get regular follow-up care and check-ups for years after your treatment.

Questions to ask your doctor

  • Am I at risk for breast cancer?
  • Should I have genetic testing to find out whether I have the breast cancer gene?
  • I have the breast cancer gene. Should I talk to my family members about getting tested to find out whether they have it, too?
  • I found something when I did my breast self-exam. What should I do now?
  • How often should I have mammograms?
  • I have breast cancer. What are my treatment options?
  • How often should I do breast self-exams?
  • I have breast cancer. Is my daughter more likely to have it, too?


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