Structure of the breast
What is breast cancer?
What is breast cancer?
Cancer in the milk ducts
Cancer in the lobes
Signs of breast cancer
Risk factors for breast cancer
Screening for breast cancer
Breast self-exam
Diagnosing breast cancer
Having a breast biopsy
Analyzing the breast biopsy
Understanding the behaviour of breast cancer
Types of breast cancer
Types of breast cancer
What is triple-negative breast cancer?
What are the stages and grades of breast cancer?
What are the stages and grades of breast cancer?
How is breast cancer treated?
Surgery to remove the tumor
Reconstructive surgery
Radiation therapy
Hormone therapy for breast cancer
Targeted therapy
What is metastatic breast cancer?
Managing your breast cancer
Understanding Breast Cancer

*This slide show represents a visual interpretation and is not intended to provide, nor substitute as, medical and/or clinical advice.

Structure of the breast

Breasts are made up of fatty tissue. They contain small chambers called lobules where breast milk is made. The milk travels through tiny channels called ducts to reach the nipples.

Lymph nodes are located inside your breasts and under your arms. They are connected by lymph vessels and they help your body fight disease.

What is breast cancer?

Breast cancer occurs when healthy breast cells become abnormal, grow out of control, and form tumors. Breast cancer can sometimes spread to other parts of the body.

What is breast cancer?

About 1 in 8 women have a lifetime risk of getting breast cancer. For men, the risk is 1 in 1,000.

Cancer in the milk ducts

Breast cancer that develops inside the milk ducts is called “ductal carcinoma in situ", or DCIS. When DCIS spreads into surrounding tissue, it is called “invasive ductal carcinoma”, or IDC.

Cancer in the lobes

Abnormal cells can develop in the lobules of the breast. They are called “lobular carcinoma in situ", or LCIS, and are not cancer. When these cells spread into surrounding tissue, they become a cancer called “invasive lobular carcinoma”.

Signs of breast cancer can include:

  • A lump in the breast or armpit;
  • A change in breast shape or size;
  • Nipple changes or discharge; and
  • Skin changes, including redness, inflammation or dimpling like the skin of an orange.

Risk factors for breast cancer include:

  • Older age,
  • Dense breasts,
  • Having breast cancer before, or having a parent or sibling who had it,
  • Having specific, inherited gene mutations called BRCA1 and BRCA2
  • Having Ashkenazi Jewish ancestry;
  • Drinking more than a small amount of alcohol, and
  • Being overweight or obese, especially after menopause.

Screening for breast cancer can help find cancer early and save lives.

Screening includes:

  • Examining your own breasts;
  • Having a healthcare provider examine them; and
  • Having an X-ray of the breasts called a screening mammogram.
Breast self-exam

You can check your own breasts about the same time each month. Feel each breast and armpit and look for any of the signs of breast cancer previously discussed.

Diagnosing breast cancer

A diagnostic mammogram is used when a change is seen on a screening mammogram. It includes extra detailed images of the breast.

A breast ultrasound is often used to determine if a suspicious lump is solid or fluid-filled. A fluid-filled lump is often benign or a cyst, while a solid lump can be cancerous or a benign fibrous growth.

A breast MRI shows more detail than a mammogram, and is often used for very small masses or changes in the breast that cannot be seen by mammogram.

Having a breast biopsy

A breast biopsy is a test that removes a few cells or a small amount of tissue from the suspicious area in the breast. There are various types of biopsies.

Analyzing the breast biopsy

A doctor called a pathologist will analyze the breast biopsy tissue by looking at the cells under a microscope and doing specific tests. Their report will let you know if you have cancer and if it grew because of estrogen, progesterone or HER2/neu protein on the cancer cell.

The results of these tests help your doctor choose the right treatment.

Understanding the behaviour of breast cancer

Doctors classify breast cancers based on how they behave. This includes:

  • Non-invasive – cancer that has not spread outside the tissue where it began,
  • Invasive – cancer that has spread and invaded healthy tissue,
  • Recurrent – cancer that returns after it was treated, and
  • Metastatic – cancer that has spread from the area where it started to other areas of the body.
Types of breast cancer

Common types of breast cancer are:

  • Invasive ductal carcinoma, and
  • Invasive lobular cancer.
Types of breast cancer

Less common types of breast cancer include:

  • Inflammatory breast cancer,
  • Tubular breast cancer,
  • Colloid breast cancer, and
  • Metaplastic breast cancer.
What is triple-negative breast cancer?

Triple-negative breast cancer means the tumor has no estrogen, progesterone, or HER2/neu protein receptors on its surface. Triple negative disease may have a worse outcome and often requires more intensive treatment.

What are the stages and grades of breast cancer?

Breast cancer staging is determined by the size and location of the cancer and whether it has spread to other areas in your body.

What are the stages and grades of breast cancer?

Breast cancers are graded 1 through 3, with 1 being the most similar to normal, healthy cells and 3 being the most different from normal cells and the most aggressive.

How is breast cancer treated?

Breast cancer treatment depends on the type and stage of your cancer. You will need treatment from a cancer team specializing in different areas of medicine.

The main treatments include surgery, radiation, chemotherapy, hormone therapy, targeted therapy, and combination treatments.

Surgery to remove the tumor

Common types of surgery for breast cancer are:

  • Lumpectomy (removing the tumor and a small portion of healthy normal tissue around it);
  • Simple mastectomy (removing the entire breast);
  • Modified radical mastectomy (removing the entire breast and lymph nodes under the arm);
  • Prophylactic mastectomy (removing one or both breasts to reduce the risk of developing breast cancer);
  • Mastectomy with reconstruction (reconstruction at the same time as removal of the breast);
  • Sentinel lymph node biopsy (procedure to determine if one or more lymph nodes contain cancer cells); and
  • Axillary node dissection (surgery to remove lymph nodes in the armpit region).

Reconstructive surgery is a procedure done to restore the appearance of the breast after a mastectomy or large tumor removal.

Radiation therapy uses radiation energy to kill cancer cells. It is mostly recommended after surgery or chemotherapy.

Chemotherapy is the use of drugs to destroy cancer cells. Chemotherapy for breast cancer is given as an IV or a pill.

Chemotherapy can be used to:

  • Shrink a tumor before surgery (called neoadjuvant chemotherapy);
  • Kill cancer cells after surgery (called adjuvant therapy); and
  • Control metastatic breast cancer (called palliative chemotherapy).
Hormone therapy for breast cancer

Hormone therapy is given if your tumor is positive for the hormones estrogen or progesterone.

Hormone therapy is used to:

  • Lower the risk of breast cancer coming back; and
  • Help shrink or slow the growth of metastatic estrogen-receptor-positive breast cancers.

Tamoxifen and aromatase inhibitors are common hormone therapies for breast cancer.

Targeted therapy uses drugs or other substances to identify and fight specific types of cancer cells with less harm to normal cells.

Targeted therapies:

  • Stop cancer cells from growing;
  • Identify and kill cancer cells; and
  • Increase the immune system’s attack on cancer cells.

HER2 is a common protein that is blocked with targeted therapy, for example trastuzumab.

Targeted therapy is often given along with chemotherapy.

What is metastatic breast cancer?

Metastatic breast cancer is cancer that has spread from the breast to other areas of the body. The most common places are the liver, bones, lungs, and brain. There is no cure for metastatic breast cancer and treatment is to prolong survival.

Today, people are living 5, 10, or more years with metastatic breast cancer due to advances in treatment.

Metastatic breast cancer treatment may include ongoing chemotherapy, hormone therapy, targeted therapy, and new innovative medicines in clinical trials, such as immunotherapy.

Survivorship is a term used to describe any one who has had breast cancer and is still living.

As a survivor, you will have different care needs than when you were in treatment. Your cancer team and primary care doctor can help you meet these needs in the years after treatment.

Managing your breast cancer

It is frightening to learn you have breast cancer. However, the information available can help you receive timely, individualized, effective treatment that can give you the best chance of being cured.

Ask your doctor or cancer team if you have any questions about your treatment plan.

Slide Show - Understanding Breast Cancer

This slide show explains what breast cancer is and how it develops. You can learn about the signs and symptoms to watch for, and the factors that can increase the risk for getting breast cancer. Breast cancer screening, diagnosis, and types of breast cancer are also explained. You can also learn about the different ways that breast cancer is treated – including surgery, radiation, chemotherapy, hormone therapy, targeted therapy, combination treatments, and clinical trials.

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This educational activity has been developed by American Breast Cancer Foundation and Mechanisms in Medicine Inc.

This activity is supported by an independent educational grant from Pfizer and Genentech.

This website is part of the Animated Patient™ series developed by Mechanisms in Medicine Inc., to provide highly visual formats of learning for patients to improve their understanding, make informed decisions, and partner with their healthcare professionals for optimal outcomes.